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Part II - Extended Abstracts Posters


Chemical composition, in vitro digestibility and nitrogen fractions of some grasses and other non grass plants, potentially ingested by dairy cattle

Luiz Aroeira, Jailton Carneiro, Domingos Paciullo, Deise Xavier, Maurílio Alvim

Introduction

Over the past years Brazilian and other international institutions have been developing silvopastoral systems and other interventions for the rehabilitation of degrading pasture lands considering the bio-physical, socio-economic and political conditions that prevail in each area. In Brazil, due its large extension, several silvopastoral systems are been used, employing different grasses and legumes trees. The nitrogenous compounds of the silvopastoral systems components, which are used for ruminant feed, may be fractionated for its adequate characterization and potential availability to be absorbed in the gastrointestinal tract. Specific information on the contents of nonprotein nitrogen (NPN), true protein, protein degradability, cell wall bound protein, etc are dependent on preliminary preparation and separation of nitrogenous components in the sample. The separation of protein and nitrogen fractions, as used by the Cornell Net Carbohydrates Protein Model, are done. Nonprotein nitrogen is denoted as the A fraction while true protein is broken down into B1, B2 and B3 fractions based on decreasing solubility. The respective fractions are dependent upon the estimation of insoluble nitrogen, true protein, and the nitrogen residual in acid detergent fiber (ADF) and neutral detergent fiber (NDF). The nitrogen that is insoluble in acid detergent is denoted as the C fraction, and is assumed to be indigestible.

The goal of this paper was evaluating the chemical composition, in vitro digestibility and nitrogen fractions of some grasses and other non grass plants, potentially ingested by dairy cattle in a silvopastoral system at Embrapa Dairy Cattle, Brazil.

Material and methods

The samples from Medicago sativa, Stylosanthes guianensis, exotic legumes trees (Acacia mangium, Acacia angustissima, Acacia auriculiformis, Gliricidia sepium) and shrub (Leucaena leucocephala), native legumes trees: (Mimosa artemisiana, Dalbergia nigra, Anadenanthera macrocarpa) and shrub (Cratylia argentea), Morus alba, Cynodon dactylon and Brachiaria decumbens, the latter under shade and at full sun, were collected at Embrapa Dairy Center, at Coronel Pacheco, Brazil, in May of 2000. This experimental station is located at approximately 22o latitude South and 43o longitude West, at an average altitude of 426 m. In this region there are two well-defined seasons, a dry season lasting from April/May to September/October, characterised by an average temperatures of 17 ºC and scarce rainfall (60 mm per month). The rainy season lasts from October to March, with an average temperature of 24 ºC and monthly rainfall of about 230 mm. The samples from the herbage were collected by simulated grazing (hand picked) and from the shrubs and trees by simulated browsing, were dried at 55 ºC during 72 hours and ground, before been analyzed. For the dry matter (DM) and crude protein (CP) analyses were adopted the AOAC (1990) recommendations. The NDF, ADF and acid detergent lignin (ADL) contents were determined following the method proposed by Goering and van Soest (1970). The in vitro dry matter digestibility was determined following the method proposed by Tilley and Terry (1963). The A fraction (NNP) was obtained by treating the sample (0.5 g) with 50 ml of distilled water for 30 minutes, and subsequent addition of 10 ml trichloroacetic acid (TCA) 10% w/v during 30 minutes (Krishnamoorthy et al., 1982). After a filtration in Whatman paper # 54 the residual nitrogen was determined. The NNP fraction was calculated by subtracting residual nitrogen from total nitrogen. The total soluble nitrogen determination was done after 3 hours incubation of the ground dry sample (0.5 g) in 50 ml borate-phosphate buffer with 1 ml of sodium azide solution. After the incubation the residual sample was filtered through Whatman # 54 using mild vacuum. The N in residue, determined by Kjeldahl, gives the insoluble fraction. Soluble protein is calculated by difference from total nitrogen. The soluble true protein (B1) can be obtained by subtracting the NNP by TCA procedure. The B3 fraction was determined by the difference between the insoluble nitrogen in neutral detergent (NDIN) and in acid detergent (ADIN) following the Sniffen et al. (1992) procedures. The C fraction was determined by ADIN. The B2 fraction was determined by difference between total N and fractions A + B1+ B3 + C (Licitra et al, 1996).

Results and discussion

The data of the legumes Stylosanthes guianensis and Medicago sativa were compared. The results showed the higher nutritional value of the alfalfa, with lower fiber content (34.1 and 54.0%), lower lignin percentage (6.6 and 10.8%), consequently higher IVDMD (69.6 and 52.5%) and higher CP content (22.6 and 11.8%). The analyzes of the nitrogenous components showed also the superiority of alfalfa in relation to S. guianensis. The sum of the A + B1 + B2, fractions respectively, soluble, insoluble rapidly degradable and intermediate degradable from alfalfa reached 94%, while from S. guianensis the result showed a percentage of 85%. The B3 and C, respectively slowly degradable and indigestible fractions were higher than the obtained from alfalfa. Once more, the data demonstrated the superiority of alfalfa upon the tropical forage legumes.

Among the legume trees, G. sepium with an IVDMD of 60.5%, a CP content of 19.6% and its indigestible fraction C of just 7.3% presented better results than the average of the other exotic legumes trees (Acacia mangium, Acacia angustissima, Acacia auriculiformes) and native legumes trees (Mimosa artemisiana, Dalbergia nigra, Anadenanthera macrocarpa), whose average values were respectively 21.4 and 21.2% of IVDMD, 18.8 and 16.7% of CP and 14.0 and 12.8% of C fraction.

The comparison between the two shrubs (Leucaena leucocephala and the native Cratylia argentea) showed higher fiber content for the Cratylia argentea (NDF of 42.6 and 59.0%, respectively), consequently lower IVDMD (56.7 and 48.3%), and lower CP content (28.9 and 21.4%). Although the sum of the A + B1 + B2 fractions were slightly higher for leucaena and its B3 value was much lower than the result found from cratylia. M. alba showed a potential nutritive value (IVDMD of 60.0%, CP of 14.8% and C fraction of 7.8%) comparable to the results obtained from G. sepium. However, its CP content was lower than that found for the legume.

However, the nutritional value of forages and trees on silvopastoral systems is a matter of concern, because the results are usually based on separated parts of the plant (e.g. leaves, stem etc). Of course, leaves will have always better nutritional qualities than others plant parts, as have been clearly stated in the literature. Leaves are not the only component of the diet in silvopastoral systems, therefore, the whole plant or if possible, a mixture of forages (legumes trees and grass) should be considered due to the associative effects on the diet fermentation (Mauricio, 2000). For a good estimation of the nutritional value of trees, shrubs and grasses it is essential to combine sampling methods, using simulated grazing and browsing, due to the multiples factors that determine the selection by the ruminant in a silvopastoral system (del Pozo, 2000).

The values found from B. decumbens in the full sun and under tree shade for NDF, IVDMD, CP and C fraction were, respectively of 64.8 and 62.3%, 55.5 and 50.0%, 8.6 and 7.0% and 3.3 and 4.2%. Malafaia, (1997) found a NDF of 75.8% characterizing a more mature grass. Consequently, his results showed lower CP content (7.2%) and higher C fraction (11.7%). For the C. dactylon results showed a lower NDF content (71.6%), higher CP content (12.3%) and lower C fraction (5.6%) than the results of Malafaia (1997), that found, respectively, values of 79.8, 10.2 and 16.9%.

Conclusions

Among the exotic legume trees, G. sepium showed better nutritive value, while the native legume trees presented the lower nutritive value. The legumes shrubs (L. leucocephala and C. argentea) and M. alba showed a potential nutritive value, been a good options for feeding cattle in silvopastoral systems. More studies should to be done, in different times of the year, with the goal of finding tropical legumes to fit in a silvopastoral systems, promoting available nutrients to the ruminant, mainly during the dry season.

References.

Association Of Official Analytical Chemists - A.O.A.C (1990) Official methods of analysis. 15.ed. Arlington. 1: 1117 pp.

Del Pozo, P (2000) Coments... in Osorio H. Agrofor2-L-@mailserv.fao.org, 12/19/2000 (in Spanish).Goering HK and Soest PJ (1970) Forage fiber analyses (apparatus, reagents, procedures and some applications). In “Agriculture Handbook”, pp. 1-19. United States Department of Agriculture, Washington, DC.

Krishnamoorthy U, Muscato TV, Sniffen CJ, et al. (1982) Nitrogen fraction in selected feedstuffs. Journal Dairy Science 65: 217-225.

Licitra G, Hernandez TM, Van Soest PJ (1996) Standardization of procedures for nitrogen fraction of ruminants feeds. Animal Feed Science Technology 57: 347-358.

Malafaia PAM (1997) Taxa de digestão das frações protéicas e de carboidratos de alimentos por técnicas “in situ”, “in vitro” e de produção de gases. Viçosa MG:UFV. Tese (doutorando em Zootecnia)- Universidade Federal de Viçosa, 85pp (in Portuguese).

Mauricio, RM 2000 Coments... in Osorio H. Agrofor2-L-@mailserv.fao.org, 210/27/2000.Sniffen CJ, O’Condnor JD, Van Soest PJ et al. (1992) A net carbohydrate and protein system for evaluating cattle diets: II- Carbohydrate and protein availability. Journal Animal Science 70: 3562-3577.

Tilley JMA and Terry RA (1963) A two-stage technique for the in vitro digestion of crops. Journal British Grassland Society 18: 104-111.

Estimating feed intake of browse species in biodiverse silvopastoral systems

Cajas-Girón YS, Mayes RW and Sinclair FL

Key words: diet composition, feed intake, forage, n-alkane, shrubs

Introduction

Multipurpose forage trees are increasingly being used as a source of nutrients for ruminants in attempts to achieve sustainable systems of animal production. However, not much is known about their nutritive value, and there is little information on feed intake of complex diets containing browse and grazing species. Most of the information that is available on feed intake of tree fodder species has been estimated using housed animals, mainly in metabolic crates and most research on feed intake in field situations has been carried out only for simple biomass (sown grass), which can be easily measured, though all measurement methods have limitations (Dove and Mayes, 1996). In studies of diets where browse species are combined with grazing species, diet composition and dry matter intake of the forage available to large ruminant animals, are important variables that may determine whether animals have an unbalanced diet, which could contribute to disturbances in their productive or reproductive status. A better understanding of the nutritive value of tree and shrub fodder is an important step in designing more appropriate feeding systems for sustainable animal production systems in the tropics.

Many different methods have been developed to estimate the amount of grass or herbaceous legumes eaten by grazing animals. However, many of these techniques may be unreliable. The majority of internal markers investigated for determining digestibility cannot be analysed as discrete compounds and incompatibility in their analyses in herbage and faeces can lead to errors in the estimation of digestibility and intake (Langlands, 1975). Long-chain fatty acids of chain length C19-C32, which are present in plant cuticular wax, were suggested by Grace and Body (1981) as internal markers as they are discrete compounds and are apparently indigestible. Following on from the work of Grace and Body (1981), Mayes and colleagues (Mayes and Lamb, 1984; Mayes et al., 1986a, 1986b) developed the n-alkane method for determining intake using a synthetic even chain alkane as an external marker for estimation of faecal output, together with a dietary odd-chain alkane as an internal (digestibility) marker. The n-alkane method appears to be more accurate than previous methods for estimating intake in grazing animals; it also accommodates differences in herbage digestibility occurring in individual grazing animals (Dove and Mayes, 1996). However, there is no published information on the use of the n-alkane method to determine both diet composition and feed intake of complex diets in the tropics for large ruminants grazing and browsing mixed herbaceous vegetation and shrub species.

The present study was designed to estimate voluntary feed intake of browse species by milking cows in silvopastoral systems and to evaluate whether the n-alkane technique could be applied to determine diet composition and feed intake in biodiverse silvopastoral systems.

Materials and methods

Field site: location and general description

The experimental work was carried at Turipana Research Centre, Cereté Córdoba, Colombia (8º51’N, 75º49’W, 18 m above sea level), a regional centre of CORPOICA, the national agricultural research institute of Colombia. Mean annual rainfall recorded at the site between 1995 and 1999 was 1380 mm. The driest period occurs between December and March, and the wettest period is from May to November.

The area used for this study is part of a multistrata silvopastoral system, which was established using four treatments of increasing botanical and structural complexity, plus a control with pasture only (see Cajas-Girón and Sinclair, in press for a complete description of the multistrata system). One plot of a dual strata treatment was used for this pilot study, comprising pasture (mainly Dichanthium aristatum and herbaceous legumes) and three shrub species (Crescentia cujete, Gliricidia sepium and Leucaena leucocephala), each at a density of 208 plants ha-1. Five milking Holstein x Zebu cows grazing this site were dosed twice-daily with paper pellets impregnated with 279mg dotriacontane (C32) over a ten-day period in March 2000 (dry season). The cows had an average daily milk yield of 5.5 kg and average live weight of 450 kg. Milking occurred once daily; the cows were dosed once in the morning after milking (7:30 am) and in the afternoon (3:00 p.m.). During the last five days of the dosing period, faecal grab samples were taken from each animal after the morning (am) and afternoon (p.m.) dosing. These samples were kept separately for each animal. A total of ten samples were therefore generated for each cow.

Samples of two grass species (Dichanthiun aristatum and Brachiaria mutica), of the five herbaceous legumes (Centrosema pubescens, Desmodium uncinatum, Teramnus uncinatus, Rhynchosia minima and Vigna sp.) and of the three shrub species (Crescentia cujete, Gliricidia sepium and Leucaena leucocephala) were collected manually by following the cows and sampling a similar fraction of the plant as grazed or browsed by the cows. Forage samples and faeces samples were dried at 60º C to a constant weight. Dried faecal and herbage samples were ground through hammer mills fitted with a 1 mm mesh sieve. Samples of herbage and faeces were taken to the Macaulay Land Use Research Institute (MLURI) in Aberdeen (UK) to determine n-alkane concentration. The alkanes were extracted from 0.1g dried faeces and 0.2g dried herbage using the modification described by Salt et al. (1992), of the method of Mayes et al. (1986a). The equipment used was a Unicam PU 4500 Gas Chromatograph (GC) fitted with a flame-ionisation detector. The column Supelco, a SPB-1 bonded phase gas column, was 30 m long x 0.75 mm i.d. glass with a film thickness of 1 mm. Data was captured on a Thermo-separations Chromjet Integrator and transferred to a computer via Spectra-Physics “Labnet” Software. Data was processed using Spectra-Physics “Winner” software followed by Microsoft Excel. The plant species composition of the diet was estimated from the patterns of alkanes found in the faeces and in the dietary plants using a least-squares optimisation routine (Excel Solver); the algorithm selected dietary plant proportions such that the sum of the squared discrepancies between the actual faecal alkane concentration (corrected for incomplete recovery), and the calculated concentration was minimised. After calculating the C32 and tritriacontane (C33) concentrations of the whole diet of each cow, feed intake was calculated using the equation described by Mayes et al. (1986a).

Results and discussion

Herbaceous and browse species - n-alkane concentrations

There were marked differences in the levels of alkane concentration between the individual species in this study (Table 1). There are a number of studies which have demonstrated large differences of the alkane patterns between species (Dove, 1992; Dove and Mayes, 1992; Laredo et al., 1991). The most abundant alkane within the herbaceous vegetation was C33, except for Dichanthium and Desmodium, which had a predominance of C27 and C31 respectively. Between the shrub species the results show a clear dominance of C33 and C31 for Crescentia and there was a marked difference between the concentration of these alkanes relative to that of Gliricidia and Leucaena. Gliricidia had substantial amount of nonacosane (C29). By contrast, the alkane concentrations in Leucaena were in general low, and the highest concentration of this species was for C29. Similar concentrations for Leucaena (C29 = 37, C31 = 29, and C33 =18) were found by Laredo et al. (1991). The results of this study agree with previous reports that the predominant alkanes of cuticular wax are C25-C35 in chain length, with C29, C31, and C33 present in the highest concentrations (Mayes et al., 1986a; Dove, 1992; Dove et al., 1996; Hameleers and Mayes, 1998).

Table 1. Concentrations of n-alkane in the cuticular wax of tropical grasses, herbaceous legumes and shrub species

Species

mg kg-1 DM

C24

C25

C26

C27

C28

C29

C30

C31

C33

C35

Grasses











Dichanthium aristatum

4

19

9

61

12

52

9

49

31

6

Brachiaria mutica

3

7

4

13

7

25

7

79

112

28

Herbaceous legumes











Centrosema pubescens

3

6

5

10

7

45

7

60

105

10

Desmodium uncinatum

2

4

3

9

7

33

7

85

52

3

Rhynchosia minima

2

5

3

5

3

11

3

63

109

6

Teramnus uncinatus

3

5

5

6

14

19

8

33

49

4

Vigna sp

2

4

3

10

5

21

7

90

185

8

Shrub species











Crescentia cujete

2

3

3

4

4

10

12

108

145

49

Gliricidia sepium

3

5

8

39

17

144

7

36

19

10

Leucaena leucocephala

2

5

5

13

19

39

11

22

11

3

Diet composition and feed intake

Mean feed intake for the five cows used in this study was 13 kg DM day-1. Hendricksen and Minson (1980) reported values of feed intake of 11.5 kg DM day-1 for cattle grazing a Lablab purpureus sward and Kibon and Holmes (1987) reported 15.1 kg DM day-1 for lactating cows. Figure 1 shows the proportion of each component for the daily intake of each cow and Figure 2 shows the mean dietary proportions of herbage (grasses and herbaceous legumes) and shrub fodder; the dietary proportions of each species contributing to the shrub fodder component are also shown.

Figure 1 Proportion of each component of the daily diet eaten by milking cows grazing a biodiverse silvpastoral system

The most remarkable result of this study was the finding that about half of the diet was provided by shrub fodder. The study was conducted during the dry season, when mean dry matter of herbaceous vegetation at the site showed a decrease from 6.2 t ha-1 in the wet season to 3.8 t ha-1 in the dry season (Cajas-Girón and Sinclair, unpublished data). Therefore, the results of this study confirm that shrub species have an enormous potential as a feed source for ruminants, on seasonally dry pastures, especially when availability of herbaceous vegetation is low.

Figure 2 Mean estimates of the proportions of the herbage and shrub species in the diet of milking cows grazing a biodiverse silvopastoral system. Dietary proportions of the three shrub species comprising the shrub fraction are also shown.

The estimates of intake obtained using the n-alkane method appear to be reasonable, in consideration of the milk yields and animal liveweights. Thus the results of this study suggest that the n-alkane technique can be successfully used to estimate feed intake of the two major dietary components: herbaceous vegetation and shrub fodder. However, due to large differences in the overall concentrations of alkanes in different plant species, the contribution of some individual species in the diet may not be accurately estimated. The differences between C. cujete and Leucaena in their overall alkane concentrations (Table 1) could have affected the estimation of the proportion of Leucaena in the diet. Despite the fact that Leucaena intake may have been underestimated, the n-alkane method provides a basis for separating four components of a complex diet and estimation of the overall feed intake of large grazing ruminants. Other methods, such as 13C and 12C isotopes, only estimate the proportion of C3 and C4 plant species in the diet. These approaches do not allow the separation of mixtures to the level of individual plant species (Dove, 1992). Visual scoring of grazed and browsed species can provide information to estimate species contributing to diet but gives little indication of the proportions of each species in the diet. The use of visual scoring to establish which species are present in the diet, together with the n-alkane method to determine the proportions of those species with sufficiently high alkane content and other markers for species with low alkane content may be an appropriate means of determining dietary composition of complex vegetation.

References

Cajas-Giron YS and Sinclair FL (in press) Characterisation of multistrata silvopastoral systems on seasonally dry pastures in the Caribbean Region of Colombia. Agroforestry Systems

Dove H and Mayes RW (1991) The use of plant wax alkanes as marker substances in studies of the nutrition of herbivores: a review. Australian Journal of Agricultural Research 42:913-952

Dove H (1992) Using the n-alkanes of plant cuticular wax to estimate the species composition of herbage mixtures. Australian Journal of Agricultural Research 43:1711-1724

Dove H and Mayes RW (1996) Plant wax components: A new approach to estimating intake and diet composition in herbivores. The Journal of Nutrition 126:13-26

Grace ND and Body DR (1981) The possible use of long chain (C19-C32) fatty acids in herbages as an indigestible faecal marker. Journal of Agricultural Science, Cambridge 97:743-745

Hameleers A and Mayes RW (1998) The use of n-alkanes to estimate herbage intake and diet composition by dairy cows offered a perennial ryegrass/white clover mixture. Grass and Forage Science 53:164-169

Hendricksen RE and Minson DJ (1980) The feed intake and grazing behaviour of cattle grazing a crop of Lablab purpureus cv. Rongai. Journal of Agricultural Science, Cambridge 95:547-554

Kibon A and Holmes W (1988) The effect of pasture and concentrate composition on dairy cows grazed on continuously stocked pasture. Journal of Agricultural Science, Cambridge 109: 293-301

Langlands JP (1975) Techniques for estimating nutrient intake and its utilisation by the grazing ruminant. In: McDonald IW and Warner ACI (eds) Digestion and Metabolism in the Ruminant. Armidale. The University of New England. Publishing Unit pp 320-332

Laredo MA, Simpson GD, Minson JD and Orpin CG (1991) The potential for using n-alkanes in tropical forages as a marker for the determination of dry matter by grazing ruminants. Journal of Agricultural Science, Cambridge 117:355-361

Mayes RW and Lamb CS (1984) The possible use of n-alkanes in herbage as indigestible faecal markers. Proceedings of the Nutrition Society 43:39

Mayes RW, Lamb CS and Colgrove PM (1986a) The use of dosed and herbage n-alkanes as markers for the determination of herbage intake. Journal of Agricultural Science, Cambridge 107:161-170

Mayes RW, Wright, IA, Lamb CS and McBean A (1986b) The use of long-chain n-alkanes as markers for estimating intake and digestibility of herbage in cattle. Animal Production 42:457 (Abstract)

Salt CA, Mayes, RW and Elston, D.A. (1992) Effects of season, grazing intensity and diet composition on the radiocaesium intake by sheep on re-seeded hill pasture. Journal of Applied Ecology 29:378-387.

Ruminal function in sheep supplemented with Pithecellobium saman pods

Alberto Navas Camacho[176], Claudia Restrepo Saenz[177], Gisselle Jimenez Tovar[178]

Introduction

The necessity to reduce pressure of pasture systems on ecosystems where cattle zones are located, necessarily passes through diversification of vegetal cover in pastures and conservation of zones of forests. The recovery of natural association of vegetal species in pasturing areas allows, besides to contribute to conservation of productive capacity of ecosystems, to count on producing trees fats (Ocampo, 1999), sugars (Roncallo et al, 1996) and proteins (Botero, 1996; Cardona and Suárez, 1995), expensive and highly restrictive as nutrients for increasing productivity on bovine production systems in tropics.

In tropical dry forest, where cattle areas are located, there are several species of legumes tree such as Rain Tree or Saman (Pithecellobium saman), Trupillo (Prosopis juliflora), Aromo (Acacia farnesiana) and Orejero (Enterolobium cyclocarpum) which, additional to environmental services of provision of shade, wind control and contribution of nutrients to plants associated, offer up to 70 tons of sugar and 24 tons of protein by tree per year (Roncallo et al, 1996).

Materials and methods

The experiment was carried out at National Centre of Research Tibaitata, of CORPOICA, localized at 2620 masl, its average temperature is 13°C. It was used 8 males sheep, with 54 kg of body weight and cannulated ruminally. The diet was based on Dishantium aristatum and Cynodon nlemfluensis hay was offered with 50% plus of their initial intake. Sheep was supplemented with urea (1% of hay intake) and mineralised salt ad libitum.

To evaluate supplementation level effect was used a Latin square design with 4 pod levels (0, 10, 20 y 30% of dry matter intake) and to evaluate supplementation form was used a completely random design with factorial arrangement 2 (whole and grounded) by 4 (level).

Results

Nutritional value of saman pods

The saman pods have shown high nutritional quality (Restrepo y Jimenez, 1999; Roncallo et al, 1996; Kathaperumal, 1988): Dry matter 90-95%, crude protein 14-20%, soluble carbohydrates 30-45%, neutral detergent fibre 16-20%, acid detergent fibre 8-10% and ash 3-4.5%.

An important characteristic of these pods is the great amount of protein existing in the seed (between 35 and 45% MS), but hardness of the seed does not allow protein and other nutrients to be used by ruminants. However, in Colombia the traditional form to offer these pods is without grinding.

Effect of saman pods supplementation on pasture’s degradability

Supplementation with low soluble carbohydrate levels has a positive effect on degradation of fibre, while high levels cause drastic reductions in their digestion. It was founded that high level Saman pods supplementation caused reductions in effective as in potential pasture dry matter degradability. This reduction was associate mainly with the degree and moment of reduction of pH, which was below 6,2 between 2 and 6 hours post-feeding. Reduction on ruminal pH during first hours post feeding, unlike were found thing in animals without supplementation in which less pH level is between 8 and 12 hours post feeding, this can be critical, because it is the same period of adhesion of bacteria to particle (Mould et al, 1982).

These reductions, typical in supplementation with starches and sugars, could be corrected by offering high fibre sources along with pods stimulating salivation (Sanchez and Preston, 1980).

Table 1. Effect of saman pods supplementation in Effective and Potential Degradability of Dry Matter Hay (%), assuming 5% of passage rate.

Saman Pods Level (% DMI)

Effective Degradability Hay (%)

Potencial Degradability Hay (%)

Whole

Ground

Whole

Ground

0

35.03

35.75

58.11

59.70

10

33.42

34.6

61.21

57.84

20

35.30

33.17

56.79

56.88

30

35.17

31.92

59.02

54.25

Trend

NS

Lineal (P<0.01)

NS

Lineal (P<0.05)

Supplemented Average

34.63a

33.23a

59.01a

56.32a

Values followed by the same letter are not significantly different.

Increasing dry matter intake with saman pods

Under adequate forage offer, dry matter intake is the main restriction to improve production in tropical livestock. The encourage of dry matter and digestible energy intake, is one of the main advantages of ground Saman pods supplementation. These one does not affect forage intake, however, increase total dry matter intake and digestible energy intake for animals with and without supplementation (See Table No.2; Navas, et al, 1999).

Microbial protein flow in ruminants supplemented with saman pods

Ground pods supplementation increases voluntary dry matter intake and size of population of ruminal fibrolytic bacteria (Navas et al, 1999). In animals supplemented with ground pods, concentration of fibrolytic bacteria was almost twice higher than animals without pods. That is nearly related with higher microbial protein flow to duodenum.

Results obtained by increasing voluntary feed intake are associated with higher digestible energy intake and microbial protein flow (Ludden and Kerley, 1997; Clark, 1993). It is suggested that supplementation with Saman pods increases these microbial protein flow. It would exist a higher dietetic protein flow, because Saman seed has a medium level of protein degradation (effective degradability 70,5% and 60,4% with 5% and 4% of passage rate respectively; Navas et al, 1999).

Table 2. Fibrolytic bacteria population (Colony Units x 108/ml), dry matter intake (gr/kg0.75) and digestible energy intake (kcal/kg0.75) as indicator of increases in microbial protein flow in saman pods animal supplemented.

Saman PodsLevel (% DMI)

Fibrolytic Bacteria Population (CUx108/ml)

Dry Matter Intake (gr/kg0.75)

Digestible Energy Intake (kcal/kg0.75)

Whole

Ground

Whole

Ground

Whole

Ground

0

3.34

5.69

64.77

67.62

76.75

80.53

10

4.47

7.14

61.21

77.81

108.31

101.38

20

5.18

11.07

54.57

74.33

104.71

131.48

30

3.86

6.53

63.26

86.90

114.06

153.96

Trend

NS

Quadratic (P=0.06)

Quadratic (P=0.08)

NS

Lineal (P<0.05)

NS

Supplemented Average

4.50a

8.25b

59.58a

79.68b

109.03a

128.94b

Values followed by the same letter are not significantly different.

Ciliates protozoa population shown a quadratic tendency, due to increases in pods intake, showing decreases in higher levels of pods supplementation (> 20%; Navas et al, 1999). It is possible because of presence of saponins in Saman pods (10% MS) explains the reduction of protozoa in high levels of supplementation and increases in microbial protein flow.

Improvement of the nutrients absorbed balance by saman pods supplementation

Saman pods supplementation increases production and proportion of propionic in total of volatile fatty acids, improving balance between fatty acids glycogenic and cetogenics. Navas et al, (1999) found that concentration of propionic in rumen was increased in quadratic relation (P<0.05) with the level of supplementation with ground Saman pods. (see table No. 3).

The most used sugar source in tropical countries are molasses, in relation to molasses, legumes pods supplementation as sugar source presents advantage to not increasing proportion of butyric in total VFA (Navas et al, 1999).

Table 3. Volatile Fatty Acids in Rumen.

Saman Pods Level (% DMI)

Total Volatile Fatty Acid Concentration (mM/Lt RF)

Propionic Acid (% Total VFA)

Glycogenic: Cetogenic Volatile Fatty Acid

W

G

W

G

W

G

0

108.09

101.00

16.48

16.61

22.93

22.79

10

104.43

131.54

18.62

18.04

25.98

24.69

20

121.60

122.12

19.77

22.05

25.85

29.43

30

106.49

116.36

18.50

21.00

23.57

27.39

Trend

NS

Quadratic(P<0.05)

NS

Lineal (P=0.08)

Lineal (P<0.05)

Lineal (P<0.05)

Supplemented Average

110.84a

123.34a

18.96a

20.36a

25.13a

27.17a

Values followed by the same letter are not significantly different.

Conclusions

The supplementation with ground Saman pods improves the efficiency of use of nutrients and the animal performance due to its effect on the balance between the glycogenic and cetogenic VFA and increasing in the relation between protein/energy in absorbed nutrients.

The increase in dry matter intake and bacteria population size in supplemented animals with ground Saman pods, suggests important increases in bacterial protein flow to small intestine. Also, macerating pods allows to incorporate protein seeds. Suplementación with these sugar sources increase digestible energy intake, but its effect is higher when pods are grounded.

This supplementation is an alternative to improve productive efficiency of bovines in pasturing, not only in dry period, but in phase of greater supply of forages, since it improves efficiency of use and voluntary consumption of these.

References

BAQUERO, L.A., A. Becerra, B. Roncallo y J.E. Silva (1999). Suplementación de vacas doble propósito con frutos de algarrobillo (Pithecellobium saman) durante el verano. IV Seminario Internacionas sobre sistemas agropecuarios sostenibles. Cali, Octubre 28-30.

BOTERO R y Botero LM (1996) Manejo de praderas y cobertura arbórea con ganado doble propósito en la costa caribe. En: II Seminario Internacional. Silvopastoreo: Alternativa para una ganadería moderna y competitiva. Valledupar, Neiva y Villavicencio. Pp. 125-140

CARDONA y Suárez (1995) Utilización de Leucaena en bancos de proteína y en asocio con gramíneas. En: I Seminario Internacional: Sistemas silvopastoriles casos exitosos y su potencial en Colombia. Bogotá, La Dorada, Santa Marta. pp 91-108

HESS D y Lascano CE (1994) Comportamiento del consumo de forrajes por novillos en pasturas de gramínea sola y asociada con una leguminosa. Pasturas Tropicales. 10, 2:12-20

KATHAPERUMAL V, Murugan M y Thirumalai S (1988) Evaluation of rain tree fruit meal (Enterolobium saman) as feed for sheep. Indian Veterinary Journal. 65: 404-406.

LUDDEN PA and Kerley MS (1997) Amino acid and energy interrelationship in growing beef steers: 1. The effect of level of feed intake on ruminal characteristics and intestinal amino acid flows. 75:2550-2560.

MINSON DJ (1990) Forage in Ruminant Nutrition. Academic Press. pp 352.

MOULD FL, Saadullah M, Haque M, Davis C, Dolberg F and Orskov ER (1982) Investigation of some of the physiological factors influencing intake and digestion of rice straw by native cattle of Bangladesh. Tropical Animal Production. 7:147:181.

NAVAS A (1991) Effect of varying the ratio of fiber to soluble sugars in the diet on rumen function and productivity of faunated and defaunated sheep. Master of Rural Science. Thesis. University of New England. NSW, Australia pp. 202.

NAVAS A and Leng RA (1991) Effect of varying the ratio of fiber to soluble sugars in the diet on rumen function and productivity of faunated and defaunated sheep. Recent Advances in Animal Nutrition in Australia, pp. 168-175.

NAVAS A, Restrepo C y Jiménez G (1999) Funcionamiento ruminal de animales suplementados con frutos de Pithecellobium saman. IV Seminario Internacional sobre sistemas agropecuarios sostenibles. Cali, Octubre 28-30.

OCAMPO, A.; J. Lean. 1999. Palm oil: an efficient and sustainable energy source in pig production: A Review. Pig news and information.20: 88-95.

ORSKOV ER (1991) Manipulation of fiber digestion in the rumen. Proceedings of the Nutrition Society. 50: 149-159.

PALMA JM y Román L (1999) Prueba de selectividad con ovinos de pelo de harinas de frutos de especies arbóreas.. IV Seminario Internacional sobre sistemas agropecuarios sostenibles. Cali, Octubre 28-30.

PETITCLERC D, Lacasse P, Girald CL, Boettcher PJ and Block E (2000) Genetic, nutritional and endocrine support of milk synthesis in dairy cows. Journal of Animal Science. 78(S3):59-77.

RESTREPO C y Jiménez G (1999) Funcionamiento ruminal de animales alimentados con forrajes de baja calidad y suplementados con frutos de Pithecellobium saman. Tesis de grado. Facultad de Zootecnia, Universidad de la Salle. Bogotá.

RONCALLO B, Navas A, Garibella A (1996) Potencial de los frutos de plantas nativas en la alimentación de rumiantes. En: II Seminario Internacional. Silvopastoreo: Alternativa para una ganadería moderna y competitiva. Valledupar, Neiva y Villavicencio. pp 231-244.

RONCALLO B, Torres E y Alvarez M (1999) Producción de vacas de doble propósito suplementadas con frutos de algarrobillo Pithecellobium saman durante la época de lluvias. IV Seminario Internacional sobre sistemas agropecuarios sostenibles. Cali, Octubre 28-30.

SANCHEZ M y Preston TR (1980) Sugar cane juice as cattle feed: Comparison with molasses in the presence or absence of protein supplement. Tropical Animal Production. 5:117-124.

Adaptation and seasonal production of 17 accessions of Leucaena in the Ponome plains

Esteban Arosemena[179], David Urriola[180]

Introduction

The studies of adaptation and biomass yield have shown that the Leucaena grows well in areas with period of drought longer than 4 months but on more alkaline soils (pH>5.6), without drainage limitations and -compaction. The poor adaptability of the Leucaena is usually owed to a combination of restrictive factors (CATIE, 1991).

Hulton (1983) points out that the satisfactory growth of the Leucaena in acid soil depends mainly on the efficient absorption of the radical calcium (Ca) and less on the tolerance to aluminum toxicity. Hulton (1983) also have shown that some varieties of L. leucocephala and L. diversifolia can use the Ca of the complexes that are formed in the low levels of pH and that the crossing between varieties and L. leucocephala act well acid soils.

The present work aimed to evaluate seventeen accessions of Leucaena with different origins, intra and inter specific crossing to identify resistant materials to plagues and diseases, high forage production and good adaptations to acid soils.

Materials and methods

This research was carried out in the experimental station Pacifico Marciaga of Instituto de Investigación Agopecuaria de Panamá (IDIAP) located at El Coco of Penonomé which is characterized to have an annual mean rainfall of 1340 mm distributed in 7 months and an mean temperature of 26.4 o C.

The soil of the experimental place possesses has the following characteristic: pH 5.3, phosphorus 2 ppm, calcium 2 meq/100, aluminum saturation 16 %, organic matter 2 % and poor drainage.

The Leucaena was sown at the rate of three seed/site at a distance of 0.75 m, to get after 30 days a plant/site. The plots were initially fertilized with 60 kg/ha of P2O5 an annually with 40 kg/ha of P2O5 and 20 kg/ha of nitrogen. The weed control was carried out manually three times a year.

The experimental unit size was of 9 m2 (16 plants/plot) to get a population of 17,777 plants/hectare.

The evaluation of leaf yield began after the year of the Leucaena growth through foliage cuts every 90 days at 1.0 m from the soil.

Seventeen accessions of Leucaena with different origins and intra inter specific crossing were evaluated: Leucaena leucocephala CIAT 17488, LI CIAT 17495, LI CIAT 17491, LI CIAT 17467, LI CIAT 17498 (K-29), LI CIAT 17502, LI K-28, LI K-60, local accessions LI cv El Coco, LI cv Río Hato, L. shannoni CIAT 17487, L. diversifolia CIAT 17461, Ld CIAT 17388, hybrid L. leucocephala CIAT 17475, hybrid L sp CIAT 17478 and hybrid L. pulverulenta CIAT 17490.

A completely randomised block design was used with three repetitions. As estimator of the superficial drainage, it was used as co variable the steepest soil slopes in the experimental units. The soil slopes were estimated from the central point of each one of the experimental units, based on the curved at level with difference of three cm between them.

The statistical model used was Yij= M+B1+Aj+? (nij - Ñ.) + Eij.

Results and discussion

A significant effect (P=0.004) of the soil slope on the forage yields was observed (Table 1). The yield was reduced in experimental units with smaller soil slope. The slope is a good estimator of the superficial drainage gradient and corroborates the susceptibility of the Leucaena genero the soil with poor drainage.

Significant statistical difference (P=0.0002) was detected in the yield of leaves among the accessions of Leucaena evaluated (Table 1). Forage production fluctuated between 6.03 to 1.96 MS t/ha/year. The best forage producer were local accessions L. leucocephala cv El Coco (coming from an Ultisol), hybrid L. Leucocephala CIAT 17475, LI CIAT 17467, hybrid L sp CIAT 17478 and LI CIAT 17498 (Table 2). Some of these accessions such as L. leucocephala CIAT 17467 and hybrid L sp CIAT 17478 have stood out in other localities of Panamá (CIAT, 1985).

Species of L. diversifolia and L. shanoni have produced the lowest forage yield. Contrary to the hybrids that produces superior forage level. L. leucocephala had a wide variation range of biomass production (Table 2).

The mean number of plant established for accessions varied little (13-15.66 plants/plot).

Conclusion and recommendations

The forage yields detected for accession of Leucaena were relatively low at El Coco plain, compared to the ones obtained in other ecosystems. However, they are acceptable for the area that presents soil limitations (drainage and acidity).

The ecotypes identified as promissory for later investigations were the following ones: local accessions L. leucocephala cv El Coco, hybrid L. leucocephala CIAT 17475 and L. leucocephala CIAT 17467.

References

CATIE 1991. Leucaena, leucaena leucocephala (LAM de Wit): Especie de árbol de uso múltiple en América Central. CATIE. (C.R.). Serie Técnica. (Informe Técnico No. 166:60 p.)

Centro Internacional De Agricultura Tropical. 1986. Proyecto Pastura en Panamá (IDIAP/RUTGERS/CIAT). In Programa de Pastos Tropicales. Informe Anual 1985. Cali, Colombia. Pp 99-110.

Gutierrez, A. 1985. Crecimiento y rendimiento de procedencia Leucaena leucocephala en Loma Larga, Panamá. Silvo energía (C.R.) 5:1-4.

Hutton, E.M. 1983. Selection and breeding of Leucaena for very acid soils. In Leucaena research in the Asian-Pacific Region in Proc. Of Singapore 1982. Ottawa, Can IDCR. Pp 23-26.

Table 1. ANOVA

Variable

Rainy period

Dry period

Annual

(Level of

Significance PR > F)

Block

0.01

0.0047

0.0027

Accessions

0.001

0.0065

0.0002

Slope

0.01

0.12

0.004

Table 2. Yield of leaf, in MS t/ha, of seventeen accessions of Leucaena. Penonomé plains. Panama.

Accesión #

Periodo Lluvioso

PeriodoSeco

Total

LI cv El Coco

5.40

0.63

6.03 a

LI CIAT 17475

5.24

0.65

5.89 ab

LI CIAT 17467

4.93

0.45

5.38abc

Lsp CIAT 17478

4.89

0.45

5.35 abc

LI CIAT 17498

4.93

0.39

5.32 abc

LICIAT 17488

4.85

0.47

5.18 abcd

Lp CIAT 17490

4.40

0.45

4.85 abcd

LI CIAT 17491

4.21

0.36

4.57 abcde

LI cv Rio Hato

3.83

0.22

4.05 bcdef

Ld CIAT 17388

3.57

0.37

3.94 cdef

LI K-28

3.34

0.24

3.57cdefg

LI CIAT 17495

3.13

0.20

3.33defg

Lsp cv Divisa

2.82

0.18

2.99 defg

Ld CIAT 17461

2.55

0.18

2.73efg

LI CIAT 17502

3.34

0.24

2.68 efg

L sh CIAT 17487

2.16

0.10

2.26 fg

LI K-60

1.88

0.08

1.96 g

a,b,c,d Means with same letters are not significantly different (P<0.05)

Potential from production of Mulberry (Morus alba) in El Salvador

Napoleón Mejía[181]

Introduction

The improvement of the quality and forage production with forage trees, represent, at the moment, a concrete and viable alternative in anyone of the modalities agroforestales and well-known silvopastoriles.

However, in a small country, as the case of El Salvador, with an evident pressure and it demands of the agricultural earth for cultivations and species of high profitability, the introduction of arboreal can be limited to conditions of marginal floors with production modalities in alive fences or I eat dispersed trees in herdsmen. But also, the paradigm for the forage production with not specialized producers, with little or almost null handling and little inversion in the pastures, drives, in a same way, to the small productivity of the systems. So that see the alternative silvopastoriles implies to exercise production conditions with modalities and species that respond to the alternatives and competitiveness of use of the earth.

The arboreal ones with high nutritious value, as the case of the mulberry (Morus alba) constituted in one of the sustainable alternatives that can respond to these conditions of competitiveness, by that that next you will discuss the environment and the conditions characteristic of the species so that it is adapted in the different ecosystems and systems of animal production in El Salvador.

Edafoclimatic characteristisc

The characteristic edafoclimáticas has to be clearly defined, since these they influence mainly in the establishment of the cultivations forages. In this it is necessary to highlight factors like the precipitation bimodal, with a rainy period that extends from may to octuber with precipitation from 1,200 to 1,600 mm annual. It is also necessary to consider the periods dry interestival or “caniculas” that it is a defined phenomenon as a dry period that happens during the rainy station, with several days with same or inferior rains to 1 mm that affects the area frequently to the lake of Guija, to the north and east of the river Lempa (north and east the country). The duration of this dry period is variable, but it can reach up to 30 days or more, and the months of occurrence are of july-august. 85% of the country corresponds to the area of life hot subtropical humid forest (Bh-ST(c)). 65% of the territory presents slopes bigger than 15%.

These characteristics should be considered since the mulberry is a bush whose critical points or requirements that it has shown for its adaptation are frank texture floors to francloamy, well drain, rich in organic matter and precipitation of 600 to 2500 mm annual, or a sheet of water of 1.5 to 2 inches under watering each 8 to 14 days.

Origin and introduction of mulberry in El Salvador

The mulberry variety Kanva-2 was introduced El Salvador from Cali, Colombia in 1991, through a project of silk worm, in that 5 hectares were planted then in San Andrés’ experimental station, in the department of La Libertad, which is property of the National Center of Agricultural and Forest Technology (CENTA, MAG).

For principles of 1994, the project of silk worm had concluded, and the plantation was recaptured by the Program of Animal Production of the CENTA, but with propose forages, beginning with it a program of evaluation of the mulberry in the components of agronomy of the plantation, use with different animal species and conservation methods. After 6 years the plantation has decreased to a hectare third in the experimental station, more the parcels that have been established in the properties of the producers that are considered in a total of 4 additional hectares.

For final of 1999 the variety was introduced Indonesia coming from the CATIE, Costa Rica that there is the date is in small areas for its multiplication.

The experience with mulberry in the country

In El Salvador it has been completed the production cycle and mulberry evaluation, of which you can expose the following results.

Forage production

In accordance with the evaluations carried out under the conditions agriculture and ecology of the country you can end up taking place during the rainy station 8.5 and 3.9 tons of MS for hectare and for year of total and eatable forage (FT and FE), respectively, in cutting every 8 weeks, and lower watering conditions it can take place in four prunings for year 17 and 7.7 t of MS ha-1 a-1. However, these yields are smaller to those reported in the Atlantic of Costa Rica of 28 and 12 t of MS ha-1 a-1 of FT and FE in three prunings per year; however, the results are superior to those obtained under conditions of dry tropic of Guatemala that in prunings every 12 weeks 13 and 5.7 t of MS ha-1 a-1 of FT and FE achieved, respectively. Demonstrating with these the restrictive one that exercises the humidity, among other, for the mulberry production in areas with dry station of more than six months, but even lower these conditions and with one of production of 3.9 t of MS ha-1 a-1 of eatable material the mulberry produces 45% more protein that the grain of corn and 38% more than the soja grain, therefore under conditions of the pacify of El Salvador the mulberry it is one of the promissory alternatives for the production of forage of high quality.

Quality of the forage

The foliage is considered as one of the foods of great nutritious value for many species of animals, it stands out the high energy content and total protein, of which is known that 86% of the total protein is true. In a same way the quality of this protein reflected as the content of essential amino acids is superior to that of the cereals, corn and sorghum; for example the lysine of the mulberry is 7 times superior that the contained one in the grain of corn, the methionine 3 times and the thriptofan 6 times. So that the use of these species constitutes a concrete alternative for the feeding of the hen and other monogastricos species.

Table 1. Least means of the eatable yield (Kg of M.S. ha-1) under five distancings of sows and three frequencies of mulberry pruning

DistancingSows (m)

Frequencies of prunings

Means

F-8

F-12

F-16

1.2x0.6

1096.10

1393.09

2033.82

1507.67

1.2x0.5

941.80

1682.54

1504.04

1376.13

1.2x0.4

1028.26

1827.62

2384.45

1746.78

1.0x.04

1195.96

1777.21

1332.66

1435.28

0.8x0.4

1333.11

1792.27

1778.08

1634.48

TOTAL

1119.05

1694.55

1806.61

1416.51

RR eat/total,%

48.49

40.35

39.73

42.10

Source: Mejía and Araujo (1997)

Table 2. Nutritional content of the whole and eatable plant of mulberry (percentage of dry matter)

Nutriment

Plants whole

Eatable foliage (leaf and tender stem

Dry matter

32.89

24.96

Crude protein

16.00

24.00

Cellular wall (FDN)

40.60

32.00

Protein in cellular wall

8.84

12.38

FDA

32.00

21.00

DIVMS

-

80.00

Calcium

1.01

2.98

Phosphorus

0.37

0.44

Source: Mejía and Araujo (1998)

Conservation

The conservation methods, as hay or silage in cool air have shown different degree of difficulty. Since you practice them they associate an additional quantity of manpower for the cut, transporting, dive, packed, drying, milled and storage. So that if the yield per day man is low the costs of the forage and their components can even be higher than those of the cereals mentioned previously.

The silage with it takes to considerations like: the age of court of the plantation should be around 8 to 10 weeks like maximum, since to more age the content of woody material is increased, what hinders the dive and it lowers the quality of the material; and the size of the dive that should be smaller than 1 inch, for that which should have a cut that facilitates this work.

The hay is also one practices that it demands a lot of manpower, therefore the activity can only be justified with materials of high quality. In the event of the mulberry it should be foreseen to harvest it of “10 to 12 weeks of age or post cut”, it is also necessary to consider that the time of exhibition in the sun it should be more than one day, for this that indicated is to defoliate the plant manually or with hooked and to expose the leaves and eatable part during some 6 hours of intense sun and with “turn over every hour”, then to store it in sacks stops later on to mill it and to incorporate it in the portion or to offer it as supplement.

Animal answer

In the feeding with bovine, the mulberry use has important implications for the material volume that it is necessary to manage under it cuts and transporting. The results in growth of heifers and in production of milk they have demonstrated reduction in the production cost with good production levels for the conditions of the country.

For the case, it can stand out the reduction in the feeding cost in 35% in the development of heifers maintaining a rate of growth up of 800 g d-1, using mulberry meal like a component of the portion, being with the use of the mulberry a more competitive production system that with other supplements acquired proteicos outside of the property and cared. With cows in milking consuming in MS 1% of the PV, it has been possible to take place under different conditions of handling from 6 to 11 liters vaca-1 día-1. On the content of fat of the milk it has cleared up the query of a possible reduction with the suplementación of fresh mulberry, by means of a work of Fuentes (1998) it was demonstrated that the suplementación with fresh mulberry during 16 serial days the variation in the percentual content of fat of the milk was of -0.77, 0.02, 0.28 and 0.25%. Reporting a minimum value of 3.6%, 7 days after the beginning of the evaluation, and at the end of the period with an average up of 3.8%.

Table 3. Weigh, gain of weight and variable costs of heifers with rations with and without mulberry meal.


Weigh initial kg/animal

WeightFinal, kg

GainDaily, g

Cost$/kg P.V.

Ration without Mulberry

108.4

169.40

871.40

1.84

Ration without Mulberry

108.7

166.00

817.09

1.27

Source: Araujo and Alfaro (1997)

With broiler commercial it has been demonstrated that the substitution of 5% of mulberry meal for concentrated commercial it doesn’t affect the speed of growth, but with levels bigger than substitution is in a backwardness of the same one, mainly with levels of the 15 and 20%, with that which the growth can backwardness from 10 to 20 days to reach 1.6 kg of weight live. Under these intensive systems of upbringings this situation should be noticed with special emphasis, considering that the real reduction of the costs settles down 15% around.

Table 4. Weigh live off four lines of broiler commercial with different levels of substitution of mulberry meal to the 42 days of age.

Percentage of Substitution

Broiler lines

Line 1

Line 1

Line 1

Line 1

5%

1257

1454

1370

1461

15%

1013

1100

1287

1288

20%

930

1006

1039

954

Source: Mejía (2001)

In other monogástricos species, as pigs the best results have been obtained with 15% of substitution of concentrated, equally with rabbits the best results are achieved with 20% of the portion.

Table 5. Biological and economic parameters of pigs fed with and without mulberry meal

 

Concentrated commercial

Level of mulberry substitution,%

Means

5

10

15

20

Daily gain, g d-1

680

650

700

740

560

662.5

Nutritious conversion

3.37

3.00

2.99

2.98

3.61

3.15

Net profit, $

117.98

208.71

225.25

237.16

128.88

200.00

Source: Trigueros and Villalta (1997)

Expectations for the production and use

Just as they have thought about the climatic conditions of the country (precipitation bimodal), the mulberry use for the animal feeding is justified given its quality. So that the expectations are bigger when including it as alternative to take place in properties in marginal areas and of hillsides, with producing of scarce resources. However, they are even many challenges that to overcome for the adoption of the species, and this is it associated to the traditional practices of production, since aptitudes of abandonment and wrong handling of the grasses, characteristic in the country, they are an obstacle that induces to that the mulberry is not adopted in the short term.

The development of the evident feasibility bioeconomic of the mulberry in the country, it should generate trust to foment it and to increase the productivity in a sustainable way in the systems of animal feeding, the same thing should be considered in countries with a rainy station concentrated on 5 or 6 months per year.

References

ALFARO, M., MARTÍNEZ, R., CENTENO, F Y ARAUJO G. 1997. Producción de leche y grasa láctea de vacas alimentadas con morera fresca (morus alba) vav kanva-2. Archivos Latinoaméricanos de producción animal (Venezuela). Vol. 5: 139-143.

ARAUJO, G., ALFARO, M. 1997. Suplementación de terneras en crecimiento con harina de morera (Morus alba) var. Kanva 2. CENTA. El Salvador. P. irr.

BENAVIDES, J.; LACHAX, M.; FUENTES, M. 1994. Efecto de la aplicación de estiércol de cabra en el suelo sobre la calidad y producción de biomasa de morera (Morus spp.). In Árboles y arbustos forrajeros en América Central. Ed. por Jorge Benavides. San José, C. R. CATIE. Vol. 2:495-514.

COTO AMAYA, O.M.; TREJO ARAUJO, J.A.; PAREDES, J. 1991. La sericultura. Agricultura de El Salvador (El Salvador). 18(1): 5-15.

FUENTES, J. 1998a. Evaluación de la fertilización con estiércol de ganado sobre la producción de morera (Morus alba). (No publicado).

FUENTES, J. 1998b. Producción y calidad de leche de vacas alimentadas con forraje verde de morera (Morus alba). (No publicado).

MEJIA, N. 1999. experiencias con árboles forrajeros en los sistemas de producción animal en el salvador. CENTA, EL Salvador. 18 p.

MEJIA, N. 2001. Datos no publicados.

MEJÍA, N.; ARAUJO G. 1997a. Evaluación de la fertilización nitrogenada sobre la producción de morera (morus albus var. kamva-2). (Datos no publicados)

MEJÍA, N.; ARAUJO G. 1997b. Producción de morera (morus albus var. kamva-2) bajo cinco densidades de siembra en el salvador. CENTA. El Salvador. P. irr.

TRIGUEROS, R.0. 1997. Evaluación del uso de concentrado artesanal suplementado Con f’arina de follaje de madrecacao (gliricidia sepium), pito (Erytrhina berteroana) y morera (Morus alba) en Ia alimentación de Conejos de la raza californiana en etapa de engorde. In Resultados de investigaci6n. CENTA. El Salvador. p. irr.

TRIGUEROS, R. O.; VILLALTA, P. 1997. Evaluación del uso de follaje deshidratado de morera (Morus alba) en la alimentación de cerdos de la raza landrace en etapa de engorde. CENTA. El Salvador. P. irr.

Advances in the implementation of high tree-density silvopastoral systems

Carlos Hernando Molina D[182]., Carlos Hernán Molina C[183].,
Enrique José Molina D. [184], Juan Pablo Molina D., Alexander Navas P.[185]

Key words: Leucaena leucocephala, Pannicum maximum var. Tanzania and Mombasa

Introduction

Researchers and producers have tested different options in order to increase the economic efficiency of milk production, an activity characterized by its low performance. These options range from systems highly dependent on chemical inputs, especially fertilizers and herbicides, to associations of grasses and trailing Leguminosae, in which one of the species included shows persistence problems in numerous cases.

In response to this situation, since 1984 El Hatico Natural Reserve and CIPAV Foundation have been investigating and implementing high tree-density silvopastoral systems with up to 10,000 Leucaena leucocephala trees/Ha. Native trees have been left within these systems in densities between 15 and 20 trees/Ha. Species include Albizzia saman, Pithecellobium dulce, Guazuma ulmifolia, Enterolobium cyclocarpum; palms such as Syagrus sancona and Attalea butyracea, and exotic species such as Prosopis juliflora, Roystonea regia and Chlorophora tinctorea, associated with grasses such as Cynodon plectostachyus and Panicum maximum var. Tanzania and Mombasa. El Hatico is located at the municipality of El Cerrito, Valle del Cauca department, Colombia, at 1000 m above sea level, with an average temperature of 24EC, annual precipitation of 750 mm and relative humidity of 75%.

Material and methods

Panicum maximum var. Tanzania and Mombasa (grasses with low protein content) were introduced in 1998 in association with Leucaena with the objective of further diversifying the silvopastoral system described in Table 1 while improving the protein to energy ratio. Before this, the system was characterized by its high offer of degradable protein from Leucaena leucocephala (30% in dry matter) and Cynodon plectostachyus (12 to 13%).

The first trial with Pannicum maximum was done in 9.6 Ha. The planting of Leucaena began in September 1998 with a distance of 1.3 meters between furrows. P. maximum was introduced 30 days after (7 kilograms of seeds/Ha), with var. Tanzania occupying 70% and var. Mombasa, 30% of the area. The animals began using the plot four months after the Leucaena was planted, allowing for rest periods of 45 days between grazing bouts.

Within the system areas were identified where P. maximum was in association with Leucaena in densities of 0, 6000, and 10000 plants/Ha. These were sampled independently in order to establish the effect of the leguminous tree on the production and quality of the grass. The sample unit was 2.6 square meters. The procedure consisted in harvesting the forage imitating animal consumption for both species. This was done once in the dry season and once in the rainy season during the second semester of 1999.

Table 1. Forage and nutrient availability in a silvopastoral system for cattle grazing compared to a Cynodon plectostachyus monoculture


Availability Ton. DM/Ha/year

RP Ton DM/Ha/year

ME Mcal/Ha/ year

Ca Kg DM/Ha/year

P Kg DM/Ha/year

Cynodon plectostachyus

25.2

3.0

59472

90.72

80.64

Leucaena leucocephala

4.3

1.1

10750

51.6

8.17

Prosopis juliflora

0.4

0.05

NA

NA

NA

Silvopastoral system (total)1 without chemical fertilization

29.9

4.15

70222

142.32

88.81

Cynodon plectostachyus monoculture with 400 kg of urea/Ha x year

23.2 (2)

2.5 (2)

56876 (3)

83.2 (3)

74 (3)

1 Mahecha (1998) 2 Ramirez (1997) 3 Ramirez & Mahecha
RP= Raw protein ME= Metabolizable energy
DM = Dry matter

Results

The effect of the density of Leucaena is shown in Table 2. Significant differences were found for the majority of variables. The best performance was detected in the highest Leucaena density treatment (10,000/Ha).

Table 2.Variation in green forage and dry matter production with tree density for P. maximum and Leucaena per grazing bout

Variable

Density of Leucaena (trees/Ha)

P

SD

0

6000

10000

P. maximum G.F. g/m2)

1505

1546

1996

0.002

107

Leucaena G.F. (g/m2)

-

120

212

0.006

17

Total G.F. (g/m2)

1505

1666

2208

0.001

107

Dry matter (g/m2)

385

322

506

0.001

30

G.F. = Green forage
SD = Standard deviation

In the evaluation of dry matter production for both varieties of P. maximum, a higher value was found for var. Mombasa (37.2 ton/Ha/year) than for Tanzania (26.89 ton/Ha/year). The latter is similar to the value shown in Table 1 for Cynodon plectostachyus, while the production of Mombasa exceeded in 30% that of Cynodon plectostachyus in association with Leucaena and Prosopis.

The results shown in Table 3 are in concordance with the consumption behavior displayed by the cows (a preference for Tanzania).

Table 3. Forage quality for P. maximum varieties

 

P. maximum

P

ES

Mombasa

Tanzania

DIVMS

59.15

61.78

0.077

0.85

RP (%)

7.94

8.99

0.102

0.37

NDF%

79.99

79.33

0.44

0.50

ADF%

48.23

45.65

0.016

0.60

Ca (%)

0.4916

0.4688

0.432

0.02

P (%)

0.3066

0.3467

0.064

0.01

RP(%) = raw protein; NDF = neutral detergent fiber; ADF = acid detergent fiber

After evaluating the raw protein contents in both varieties of P. maximum significant differences (P<0.001) were found between the association with Leucaena (9.86%) and the system without leguminous trees (6.79%).

Table 4. Impact of silvopastoral systems at El Hatico Natural Reserve (1996-2000)

Variable

YEAR

1996

1997

1998

1999

2000

Total Area (Ha)

89

89

89

73

51

Area without Leucaena (Ha)

75,4

68,2

61,8

29,8

0

Area with Leucaena (Ha)

13.6

20.8

27.2

43.2

51

# of milked cows

299

286

259

266

230

Animal load/Ha x yr

3.35

3.21

2.91

3.74

4.50

Milk production (l/Ha x yr)

7436

8298

9770

11684

17026

Table 4 summarizes the impact of high tree-density silvopastoral systems at El Hatico. Production values per hectare with active milking cows (excluding cows in dry period) during the last 5 years are presented. The 129 % increment in milk production/Ha from 1996 to 2000 stands out. The main factor responsible for this is the growth in silvopastoral systems (Cynodon plectostachyus, Panicum maximum, Leucaena leucocephala and Prosopis juliflora).

The reduction in carrying capacity from 1997 to 1998 is due to the decision of eliminating chemical fertilization (400 kg of urea/Ha x yr) in the systems without Leucaena.

Out of the 51 hectares of silvopastoral systems in the year 2000, 25 Ha. were in association with Cynodon plectostachyus, Leucaena leucocephala and Prosopis juliflora with an average age of 5 years. 16 hectares have P.maximum (Tanzania and Mombasa varieties) associated with Leucaena and Prosopis with two years of service. The remaining 10 Ha initiated production during the first months of year 2000 with a mixture of grasses (Cynodon plectostachyus, Panicum maximum var Tanzania) associated with Leucaena and Prosopis juliflora.

Conclusions

P. maximum varieties Tanzania and Mombasa show very good performance in the agroclimatic conditions of El Hatico Natural Reserve reaching and surpassing the biomass production of the association Cynodon plectostachyus-Leucaena-Prosopis. Keeping into account the erect growth of P. maximum, it is convenient to associate it with C. plectostachyus which covers all the empty spaces left by P. maximum.

High levels of milk production per hectare per year (>15.000 l/Ha x yr) are possible with a high tree-density system without relying on chemical inputs, such as fertilizers, herbicides, and insecticides.

Silvopastoral systems differ from systems based on grass monoculture in that productivity (represented in terms of biomass quality and quantity) increases with time.

Diversification of grass and tree species within the system not only benefits cattle but also offers proper habitats for different biological communities (birds, butterflies, ants) as has been shown by studies done recently in the Reserve (Cárdenas G. 1997, Ramírez M. et al. 2000 and García T. Ramos A.F.2000).

References

Cárdenas G. 1998. Comparación de la composición y estructura de la avifauna en diferentes sistemas de producción. Universidad del Valle, Facultad de ciencias, Departamento de biología, Cali, Colombia.

Mahecha L. 1998. Análisis de la relación planta-animal desde el punto de vista nutricional, en un sistema silvopastoril de Cynodon plectostachyus, Leucaena leucocephala y Prosopis juliflora, en el Valle del Cauca. Tesis de Maestría en producción animal Tropical. Universidad Nacional de Colombia. Palmira 153 p.

Mahecha L. Rosales M. Y Molina C.H. 1999. Experiencias de un sistema silvopastoril de Leucaena leucocephala, Cynodon plectostachius y Prosopis juliflora en el Valle del Cauca. Agroforestería para la producción animal en América Latina, CIPAV-FAO. Páginas 407-419.

Navas A. (1999) Producción y calidad de Guinea var. Tanzania y Mombasa asociada a Leucaena leucocephala en la Reserva Natural El Hatico. Trabajo de pasantía de último año en Medicina Veterinaria y Zootecnia Univeresidad de Caldas, Manizales-Colombia.

Ramírez H. 1996 Evaluación de dos Sistemas Silvopastoriles Integrados por Cynodon plectostachyus, Leucaena leucocephala y Prosopis juliflora. Trabajo de tesis para optar por el título de Ingeniero Agrónomo, Universidad Nacional de Colombia.

Rumen dry matter degradability of browse species in semiarid areas of Mexico in the dry season

Camacho Morfín D.[186], Sandoval Castro C.[187] y Ayala Burgos A.[188]

Key words: chemical constituents, forage quality, semiarid Mexico, tree fodder

Introduction

Arid and semiarid areas occupy most of the total surface of Mexico, that region exhibit considerable diversity in plant community and selective utilization by the animals. Native tree fodder and shrubs occur throughout that areas and cattle, goats and sheeps browse them under extensive systems of grassing. Although, some woody fodder had been studied by different researchers (Eg.: Ramírez and Lezama-Torres, 1997), but, the information in Mexico is scarce on the nutritive value of trees and shrubs fed the ruminant livestock. The aim of this study was evaluate the parameters of ruminal degradation of woody fodder from semiarid area. The results should help us better understanding the feed potential of such forages.

Materials and methods

The samples come from Mezquital Valley, it is located at an altitude from 1000 to 2600 m asl, latitude 20º 22' N; longitude 98o 54' and 99º 38' W, and has an average annual rainfall between 150 and 1000 mm, temperature between 15 and 20 ºC, the climate is BS1 kw(w), semi dry temperate with rainfall in summer and scarce winter precipitation. The soil is an feozem. Approximately 5 kg of branches samples from browse trees and shrubs were collected at the dry season in the Mezquital Valley region, March and April 1999. Samples from each plants species were collected from at least 10 individual trees or shrubs, they were oven dried at 60 oC for 48 h and stored in sealed plastic bags; samples were milled through a 3 mm screen for sacco analysis and a 1 mm screen for chemical analysis.

The dry matter (DM) in sacco degradation analysis was carried our according to the procedure described by Bhargava and Ørskov (1987). 3 g samples were weighed into nylon bags and incubated in three rumen-fistulated cows (284+53 kg) for 3, 6, 12, 24, 48, 72 and 96 h. The cows were fed one time daily on a 93 % Taiwan grass (Pennisetum purpureum) and 6 % concentrate. On removal the nylon bag were thoroughly washed 4 times of 5 minutes in a washing machine in cold water and dried at 60 oC for 48 h. Washing soluble were measured by soaking every sample at 39 oC for 15 minutes, filter and dried at 60 oC for 48 h. The dry matter in sacco degradation data were fitted to the exponential equation: P=a+b(1-e-ct) (Ørskov and McDonald, 1979).

Where a is the soluble fraction; b, fermentable fraction; a+b, potential degradability; c, degradation rate.

Dry matter, nitrogen and ash analyses were completed as described by AOAC (1990), neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin were determined according Goering and van Soest (1970). Correlation analysis was used to evaluate relationships between chemical composition and ruminal degradation parameters.

Results

The species studied are given in Table 1, there were many families that can use like fodder in dry season. The characteristic of the sample spices are shown in Table 2, in general the plants were in flowering except Bellota and Tepozan, the branches diameters were how the literature enjoin, less than 10 mm.

Table 1. Common and scientific name of browses from semiarid areas in Mexico at dry season

Common name

Scientific name

Family

Azibuche

Celtis sp

Ulmaceae

Bellota

Quercus sp.

Esterculiaceae

Huizache

Acacia farnesiana L. Willd

Leguminoceae

Madroño

Arbutus xalapensis H.B.K.

Ericaceae

Membrillo

Amelanchier denticulata (H.B.K.)

Rosaceae

Mezquite

Prosopis laevigata

Leguminoceae

Pirúl

Schinus molle L.

Anacardiaceae

Tamarindo

Dodonaea viscosa Jacq.

Sapindaceae

Tepozán

Buddleia cordata H.B.K.

Loganiaceae

Table 2. Branches characteristic of browses from semiarid areas in Mexico at dry season.

Common name

Scientific name

Branches longitude cm

Diameter mm

Maturity stage

Azibuche

Celtis sp

7

3.1

Flowering

Bellota

Quercus sp.

4.6

3

Vegetative

Huizache

Acacia farnesiana

17

2.5

Flowering

Madroño

Arbutus xalapensis

5.65

3

Flowering

Membrillo

Amelanchier denticulata

4

3

Flowering

Mezquite

Prosopis laevigata

21

4

Flowering

Pirúl

Schinus molle

27.5

1.6

Flowering

Tamarindo

Dodonaea viscosa

16

1.65

Flowering

Tepozán

Buddleia cordata

14

4.5

Vegetative

Chemical composition of browse plant branches is shown in Table 3, generally, there were wide variation between chemical components. The content of dry matter was high for all woody; Mezquite and huizache had the highest contents of nitrogen and intermediate of lignin. Tepozan shows an interest behavior low lignin and high NDF.

Table 3. Chemical composition of of browses from semiarid areas in Mexico at dry season.

Specie

DM
%

N
%

Ash
%

NDF
%

ADF
%

LIGNIN
%

Azibuche

48,50

1,09

5,13

52.21

31.87

14.81

Bellota

76,12

1,05

6,78

64.97

69.16

26.10

Huizache

53,13

1,97

3,61

57.62

32.23

15.19

Madroño

54,54

0,71

6,21

38.98

23.92

13.18

Membrillo

69,03

0,73

4,25

48.61

32.71

13.93

Mezquite

35,14

2,76

6,05

45.01

27.98

11.71

Pirúl

53,87

1,43

7,70

40.17

21.36

10.41

Tamarindo

46,50

1,26

4,84

36.35

25.14

11.42

Tepozán

53,67

1,05

4,73

58.47

34.14

9.09

DM= Dry matter; N= Nitrogen; NDF= Neutral detergent fibre; ADF= Acid detergent fibre

In sacco degradabilty data are shown in Table 4. The highest contents of a correspond to Madroño and Mezquite and the lowest to Tepozan. There was significant negative correlation between NDF content and soluble fraction (a)(p<0.05; R= -0.733).

The fermentable fraction (b) was high of Tamarindo, Tepozan and Pirul were significantly highter (p<0.05). There was significant negative correlation between lignin content and b (p<0.001, R=-0.838) and potential degradability (p<0.001, R=-0.855).

The in sacco degradability data suggest that leaves from woody species studied are of high nutritive value.

Table 4. Dry matter ruminal degradability parameters (%) of browses from semiarid areas in Mexico at dry season.

Specie

Parameters

a

b

a+b

c

Azibuche

22.27 de

47.29 bc

69.57 c

0.044 ab

Bellota

24.41 cd

14.19 g

38.60 e

0.022 d

Huizache

23.17 d

24.64 f

47.81 d

0.024 d

Madroño

38.87 a

43.60 cd

82.47 b

0.016 d

Membrillo

33.43 b

40.35 de

73.78 c

0.034 c

Mezquite

36.07 ab

36.82 e

72.89 c

0.042 abc

Pirúl

27.32 c

65.43 a

92.74 a

0.021 d

Tamarindo

32.85 b

52.05 b

84.89 b

0.051 a

Tepozán

18.77e

63.83 a

82.60 b

0.035 bc

Acknowledgements

D. Camacho Morfín acknowledges the scolarship received from CONACYT-Mexico

References

A.O.A.C. Association of Official Analytical Chemists (1990) Official Methods of Analysis. 15 th ed. Association of Official Analytical Chemists. Washington D.C. USA. pp.69-88

Goering K. and van Soest P.J (1970) Forage fibre analysis: Apparatus, reagents, procedures and some applications. Agric. Handbook 379. 1-20.

Ørskov E.R. and McDonald I (1979) The estimation of protein degradability in the rumen from incubation measurements weighted according to the rate passage. J. Agric. Sci. Camb. 92. 499-503.

Bhargava P.K. and Ørskov E.R (1987) Manual for the use of nylon bag Technique in the evaluation of feedstuffs. The Rowett Research Institute. Bucksburn. Aberdeen. Scotland. 1-21

Investigating the biological basis of tree fodder evaluation by farmers

D.B. Subba[189], P.J. Thorne[190], F.L. Sinclair[191]

Key words: cattle, feeding trials, local knowledge, Nepal, palatability

Introduction

Farmers in the hills of Nepal have a detailed indigenous knowledge system for describing the nutritive value of tree fodders (Thapa et al., 1997) that they use in the management of fodder resources to cope with feed scarcity during the winter. Previous investigation of farmers’ knowledge in Solma revealed two local classification systems for tree fodders, posilopan and obhanopan (Thapa et al., 1997). This terminology has also been reported from elsewhere in Nepal (Rusten and Gold, 1991; Sinclair and Joshi, 2001).

Walker et al. (1999) found that farmers’ ranking of fodders for obhanopan and posilopan were independent of each other, suggesting both that farmers’ knowledge is sophisticated in differentiating nutritive value into more than one component and that its biological interpretation may be complex. Thorne et al. (1999) compared farmers’ ranking of fodders with chemical analyses and found that posilopan appeared to correspond to protein supply to the duodenum in cattle, while obhanopan appeared to correspond to in-vitro digestibility of tree fodders. Farmers, in preferring more obhano fodders, contradicted animal nutritionists’ ranking of the same group of fodders. The farmers were valuing less digestible feeds, which is rational if feed is scarce and the satisfaction of animal appetite, thereby controlling behaviour, is a major objective.

The previous research on the biological basis of farmers’ knowledge has relied upon comparison of in vitro measurements of the nutritive value of fodders with farmers’ ranking. The present research uses on-farm feeding trials to confirm and to further investigate the biological interpretation of the local criteria used by farmers to describe and assess fodder value.

Materials and methods

Local knowledge of tree fodder quality

Six tree fodder species (Table 1) were selected for study following a participatory rural appraisal at Patle that identified them as the most important dry season fodder resources. A randomly selected group of 10 farmers (five men and five women) from Patle were interviewed about their perception of these fodders and the attributes that they used to evaluate them. They were asked to rank the six different tree fodders separately in terms of their posilopan (see above), obhanopan (see above), adilopan (this refers to satisfaction of appetite - a small quantity of a very adilo fodder will satisfy appetite for a long time) and their effect on milk yield and butterfat content. The group of farmers was further asked for overall ranking of the species in terms of fodder quality.

Table 1: List of common and scientific names of the six tree species studied.

Tree species

Scientific name

Nebharo

Ficus nerrifolia

Raikhanyu

Ficus semicordata

Amliso

Thysanolaena maxima

Ghotli

Sambucus hookeri

Gogun

Saurauria nepaulensis

Malbans

Bambusa nutans

Palatability study

A palatability study was carried out on farms in Sinjaligaon (Dhankuta district) using four cattle to evaluate five of the six species of fodder trees under study (ghotli was unavailable in Sinjaligaon at the time of the study). One kilogram of each species was intermixed and the animals were allowed access to the test mixture for one hour. Selective preferences (sequence of first selection and bites observed at specific time intervals) were noted by trained, individual observers. Refusals at the end of the test period were weighed and intake of each test fodder was calculated. The study was conducted twice per day over a three day period; early in the morning (before the first feed of the day) and after noon (when the animals were full).

Feeding trial

The proposed experiment was introduced to farmers in the Patle area in order to explain its purpose and the potential benefits for them. Farmers willing to participate in the study who also possessed enough fodder trees of the species under study were selected for inclusion. A total of 27 lactating cows were selected, with four cows were allocated to the malbans, amliso, ghotli and nebharo treatments, five cows to the gogun treatment and six cows to the raikhanyu treatment. These allocations reflected the distribution of the different tree species amongst the participating farms. Each treatment diet was offered at 3% of estimated body weight to supplement a basal diet consisting of a commercial ration fed at 1% of estimated body weight and rice straw fed ad libitum. The experiment covered a period of 22 days with three days pre- and post-experimental feeding of the trial rations. Milk samples were collected at three day intervals before, during and after the experiment to allow the impact of treatment diets on changes in the levels of milk volume, milk fat and milk solid not fat (SNF) to be examined. Responses in the experimental variables to tree fodder feeding were analysed using a REML variance components analysis.

In-situ analysis of feeds

The samples collected during the on-farm feeding trial were bulked for each fodder tree species and transported immediately to the lab for analysis. Rumen degradability of the dry matter was determined using three buffalo calves. The disappearance of dry matter from nylon rumen bags was measured at 4, 8, 16, 24, 48 and 96 hrs of incubation and fitted to the exponential model of Orskov and McDonald (1979).

Results

Local knowledge of tree fodder quality

Farmers’ perceptions of overall fodder quality corresponded exactly to their posilopan rankings (Table 2).

Table 2. Farmers rankings of tree fodders for different nutritive value criteria.

Rank order

Posilopan

Obhanopan

Adilopan

Overall quality

1

Malbans

Ghotli

Malbans

Malbans

2

Ghotli

Malbans

Amliso

Ghotli

3

Amliso

Amliso

Ghotli

Amliso

4

Nebharo

Raikhanyu

Nebharo

Nebharo

5

Raikhanyu

Nebharo

Raikhanyu

Raikhanyu

6

Gogun

Gogun

Gogun

Gogun

Palatability study

Results of the palatability study are summarised in Table 3.

Table 3. Preferences of cattle and intake over a one hour period for five fodder tree species.

Rank

Order of preference

Intake

Rank order

% consumed

1

Malbans

Nebharo

92

2

Amliso

Raikhanyu

78.5

3

Nebharo

Amlsiso

77

4

Raikhanyu

Gogun

72

5

Gogun

Malbans

47

Feeding trial

The two most readily consumed tree fodders under the conditions of the study appeared to be gogun and nebharo whilst malbans and amliso were least readily consumed (p<0.01). Significant impacts on milk solids not fat (SNF) contents were also observed (p<0.01), with ghotli and raikhanyu reducing SNF content and the other four tree fodders apparently enhancing it.

In-situ analysis of feeds

Rumen degradability parameters for the six tree fodders, calculated using the equations of Orskov and MacDonald (1979), are presented in Table 4.

Table 4. Degradation characteristics of dry matter of tree fodders.

Tree species

Fitted parameters

Potential degradability (%) (a+b)

Effective degradability at outflow rate (h-1)

a (%)

b (%)

c (h-1)

0.05

0.02

Raikhanyu

17.6

52.3

0.026

69.9

35.4

47.1

Amliso

21.1

44.2

0.011

65.2

29.25

37.1

Gogun

16.7

66.6

0.015

83.3

31.99

45.2

Ghotli

14.8

66.5

0.036

81.3

42.5

57.4

Nebharo

21.4

36.6

0.017

58.0

30.89

38.5

Malbans

14.4

30.8

0.032

45.2

26.53

33.5

Discussion

Degradability data were broadly consistent with impacts on feed intake observed in the on-farm feeding trial, although these contradict somewhat the findings of the short term palatability and intake studies. For example, gogun certainly appeared to be consumed most readily by animals in the longer term study and was readily degraded in the rumen. This would suggest, perhaps, a limitation due to unacceptable organoleptic properties rather than intrinsic nutritional characteristics. These findings are actually quite consistent with farmers’ observations that gogun is not palatable but does not normally exert a great fill effect on the animal. Interestingly, palatability would appear to be an important component of farmers’ criteria for assessing tree fodder. Comparison between Table 2 and Table 4 indicates that farmers’ most preferred species, malbans, was the least degradable whilst their least preferred species, gogun, was most degradeable and consumed to the greatest extent in the longer-term feeding trial. This observation tallies with earlier findings reported by Thorne et al. (1999). These authors suggested that farmers’ preferences for less digestible tree species might reflect a need to moderate the behaviour of stalled animals experiencing periods of feed shortage.

Conclusion

The biological bases of the indigenous knowledge of farmers for evaluating tree fodder quality has been to some extent confirmed in terms of effects on animal performance. It is clear, however, that when selecting tree fodder species, farmers consider multiple factors (feed intake, digestibility, nutrient availability, productive parameters and control of animal behaviour), creating a complex domain for providing decision support. While serious methodological challenges remain, further investigation using local feeding management as the basal diet may confirm expectations emerging from interpretation of the results of the present trials, provide new insights and enable predictive systems to be developed for effective utilisation of tree fodder on-farm.

Acknowledgements

The authors are thankful to the farmers of Patle, Phalante, Pakhribas and Barbote VDCs for their support in the feeding experiment and their active participation throughout the study period. Messers UB Wagle, BB Tamang, Y Basnet, AS Mehera and N Bhandary are also gratefully acknowledged for their support on knowledge acquisition, conducting field experiments and laboratory support activities on-station. This publication is an output from a research project funded by the United Kingdom Department for International Development (DFID) for the benefit of developing countries. The views expressed are not necessarily those of DFID. R7637 Livestock Production Programme.

Reference

AOAC (1980) Official Methods of Analysis. 13th Edition, Association of Official Analytical Chemists, Washington, DC

Orskov ER and McDonald I (1979) The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. Journal of Agricultural Science 92: 499-503

Rusten EP and Gold MA (1991) Understanding an indigenous knowledge system for tree fodder via a multi-method on farm research approach. Agroforestry Systems 15: 139-165

Sinclair FL and Joshi L (2001) Taking local knowledge about trees seriously. In: Lawrence A (ed) Forestry, Forest Users and Research: New Ways of Learning. ETFRN, Wageningen pp 45-61

Thorne PJ, Sinclair FL and Walker DH (2000) The interactive role of fodder trees in hillside landscapes: using fuzzy sets to combine farmers’ knowledge with science. In: Krishnapillay B, Soepadmo E, Arshad NL, Wong AAH, Appanah S, Chik SW, Manokaran N, Tong HL and Choon KK (eds) Forests and Society: the Role of Research. XXI IUFRO World Congress, 7-12 August 2000, Kuala Lumpur, Malaysia. Sub-plenary sessions Volume 1. IUFRO, pp 743-751.

Thorne PJ, Subba DB, Walker DH, Thapa B, Wood CD and Sinclair FL (1999) The basis of indigenous knowledge of tree fodder quality and its implications for improving the use of tree fodder in developing countries. Animal Feed Science and Technology 81: 119-131

Thapa B, Walker DH and Sinclair FL (1997) Indigenous knowledge of the feeding value of tree fodder. Animal Feed Science and Technology 67: 97-114

Van Soest PJ and Robertson JB (1985). Analysis of Forages and Fibrous Foods. A Laboratory Manual for Animal Sciences. Cornell University, USA

Walker DH, Thorne PJ, Sinclair FL, Thapa B, Wood CD and Subba DB (1999) A systems approach to comparing indigenous and scientific knowledge: consistency and discriminatory power of indigenous and laboratory assessment of the nutritive value of tree fodder. Agricultural Systems 62: 87-103

Phenology and nutritive value of the foliage of some forage tree species of Caatinga

João Ambrósio de Araújo Filho, Fabianno Cavalcante de Carvalho[192],
Nilzemary Lima da Silva[193]

Introduction

Researches on the botanical composition of the diet have shown the importance of native forage trees as source of fodder for the ruminants in caatinga. A total of 23 tree species, corresponding to 70% of the arboreous species on the sites, was found to participate in the botanical composition of the diets of goats and sheep (Araújo Filho et al., 1998). Due to high predominance of leguminous species among the caatinga forage trees, the protein content of the diet has been found adequate, even in the dry season, in most of the researches (Pfister, 1983 and Araújo Filho et al., 1996). The protein content in those diet studies varied from 25% in the wet season to 9,0% in the dry period. However, very few researches have been conducted on the nutrient content of the foliage of the caatinga trees and even less on their phenology (Pereira et al., 1989). This research dealt with the study of the nutrient content and digestibility of the foliage of some caatinga forage trees, with respect to their annual phenologic cycle.

Material and methods

The data were collected at the Goat National Research Center, of EMBRAPA, Sobral, Ceará Brazil, in a representative area of the Sertão ecosistem, in the period from 1993-1995. The climate of the area is BShw’ type and the soils are predominantly non-calcic brown, on a rolling topography.

Auxemma oncocalyx Bauhinia Cheilantha, Caesalpinia bracteosa, Caesalpinia ferrea, Mimosa caesalpinifolia, Mimosa hostilis and Zyziphus Joazeiro, the most common forage trees, on the site of study, were selected. From these, Caesalpinia ferrea, Mimosa hostilis and Zyziphus Joazeiro were evergreen. Ten plants per species were permanently marked and visited every week, when the phenophases were observed and samples were harvested from each tree species for laboratory analysis. The following phenophases were considered: vegetative, flowering, fruiting and dormancy. The samples were analyzed for their dry matter (D.M. at 105 0C), crude protein, lignin and total tanins contents and dry matter in vitro digestibiliy.

Results and discussion

The dry matter content plays an important role on the fodder intake. The results presented by Table 1 indicate that from the vegetative to the fruiting stage the foliage of the trees species were adequate for consumption by the animals. The crude protein contents of all the tree species were above the minimum needed for the diet of the ruminants (c. 7,0%), along the phenologic cycle, except for the dormancy phase, when only Bauhinia cheilantha and Caesalpinia bracteosa would meet the minimum requirements (Table 1). The lignin percentage was always high for Auxemma oncocalyx and low for Bauhinia cheilantha and Caesalpinia bracteosa, along the phenologic cycle (Table 2). As an average, it varied from 12.1% at the vegetative stage to 20.0% at the dormancy. Total tanins were high for the two species of Caesalpinia, while Zyziphus Joazeiro kept the lowest value (Table 2). The total tanin content apparently does not interfers with the palatability of the tree fodder. In fact, Caesalpinia ferrea, presenting a high total tanin percentage, has a very palatable forage. On the other hand, the odor, associated with Caesalpinia bracteosa, seems to be the major consumption restrainer. Zyziphus Joazeiro, Bauhinia cheilantha and Caesalpinia bracteosa showed the best digestibility values, at the vegetative phase. However the last two species kept the high percentage up to the fruiting stage (Table 3). The lignin content seemed to affect de fodder digestibility of the caatinga trees. In fact, high lignin content was always associated with low digestibility (Tables 2 and 3).

Conclusions

The nutritive value of the tree foliage varied according to the phenologic phase, being higher at the vegetative stage, when the forage production is also at its high. The total tanin content may not be an intake restrainer for caatinga forage trees, while high lignin percentage reduces digestibility. Caesalpinia, bracteosa and Bauhinia cheilantha are the best selections for hay production among the studied forage trees of caatinga.

References

Araújo Filho JA, Gadelha JA, Souza PZ, Leite ER, Crispim SMA and Rego MC (1996). Composição botânica e química da dieta de ovinos e caprinos em pastoreio na região dos Inhamuns, Ceará. Revista da Sociedade Brasileira de Zootecnia 25(3): 383-395.

Araújo Filho JA, Leite ER and Silva NL (1998). Contribution of woody species to the diet composition of goat and sheep in caatinga vegetation. Pasturas Tropicales 20(2): 41-45.

Pereira, RMA, Araujo Filho JA, Araujo ZB, Lima RV, and Paulino FDG (1989). Estudos fenológicos de algumas espécies da caatinga. Ciência Agronômica 20(1,2): 11-20.

Pfister JA (1983). Nutrition and feeding behavior of goat and sheep grazing deciduous shrub woodlandin Northeastern Brazil. Utah State University. PhD dissertation.

Table 1. Mean dry matter and crude protein content of caatinga forage trees, according to their yearly phoenologic phases of vegetative (VEG), flowering (FLO), fruiting (FRU) and dormancy (DOR), in the 1993-1995 period. Sobral, Ceará, Brazil.

Phoenophase/Species

Dry Matter (%)

Crude Protein (%)

VEG

FLO

FRU

DOR

VEG

FLO

FRU

DOR

Auxemma oncocalyx

21.8

31.9

36.4

83.7

20.3

16.5

16.5

8.3

Bauhinia Cheilantha

25.1

33.4

37.4

90.9

20.7

18.1

13.3

9.7

Caesalpinia bracteosa

45.4

45.8

46.6

87.1

16.9

15.6

14.4

11,2

Caesalpinia ferrea

53.7

57.3

53.7

-

15.1

14.3

13.3

-

Mimosa caesalpinifolia

33.6

32.6

34.9

90.2

19.2

15.7

14.3

5.6

Mimosa hostilis

34.5

38.7

36.1

-

19.6

16.6

12.1

-

Zyziphus Joazeiro

24.3

30.6

44.8

-

20.6

16.1

12.2

-

Average

34.1

38.6

41.4

88.0

18.9

16.1

13.7

8.7

Table 2. Mean lignin and total tanin content of caatinga forage trees, according to their yearly phoenologic phases of vegetative (VEG), flowering (FLO), fruiting (FRU) and dormancy (DOR), in the 1993-1995 period. Sobral, Ceará, Brazil.

Phoenophase/Species

Lignin (%)

Total tanin (%)

VEG

FLO

FRU

DOR

VEG

FLO

FRU

DOR

Auxemma oncocalyx

20.9

20.9

18.8

20.2

3.7

7.2

9.1

3.0

Bauhinia Cheilantha

9.1

12.5

12.6

15.3

5.7

6.4

12.2

3.9

Caesalpinia bracteosa

6.6

11.2

12.7

11.7

20.6

19.1

16.2

9.5

Caesalpinia ferrea

8.7

15.2

15.9

-

17.7

18.9

18.7

-

Mimosa caesalpinifolia

13.5

18.2

19.7

22.9

4.9

11.0

16.7

8.6

Mimosa hostilis

14.4

16.2

17.4

-

9.9

11.6

16.2

-

Zyziphus Joazeiro

11.9

13.3

14.2

-

0.1

0.1

1.3

-

Average

12.2

15.4

15.9

17.5

8.9

10.6

12.9

6.3

Table 3. Mean in vitro dry matter digestibility (%) of caatinga forage trees, according to their yearly phoenologic cycle, in the 1993-1995 period. Sobral, Ceará, Brazil.

Phoenophases/Species

Vegetative

Flowering

Fruiting

Dormancy

Auxemma oncocalyx

25.9

24.4

21.9

12.7

Bauhinia Cheilantha

59.7

58.9

55.9

35.5

Caesalpinia bracteosa

58.4

52.5

50.4

30.9

Caesalpinia ferrea

43.1

37.5

30.4

-

Mimosa caesalpinifolia

39.2

33.0

28.7

22.9

Mimosa hostilis

29.5

32.8

26.0

-

Zyziphus Joazeiro

66.6

35.3

30.0

-

Average

46.1

39.2

36.0

25.5

Yield and nutritive quality of Zapoteca formosa (Kunth) H. Hern. Subsp. formosa: A new forage shrub in Venezuela

H. J. Delgado Gómez[194], R. González Anciani[195], G. López, D. Urdaneta[196]

Key words: defoliation frequency, cutting height, shrub legume, Zapoteca formosa

Introduction

The tropical America is the center main of the diversity and origin of legumes. Most of the livestock production in the sub-humid region of Maracaibo highlands, Venezuela, is based on guinea grass (Panicum maximum, Jacq.) under grazing conditions. This region is the nature habitat of Zapoteca formosa (Kunth) H. Hern. Subsp. formosa, and has an area of about 200 000 ha used for milk and meat production. Currently, the main problems that negatively affect animal production in the region is the irregular distribution of the forage production and quality during the year and bad management grazing practices, consequently, the farms have high costs of supplementary feed.

An alternative to these problems is the use of legumes, specially the native ones. Z. formosa is a native shrub from Maracaibo that is well accepted by livestock and appears to have a high nutritive value. The use of this legume in the animal production systems could be an economical alternative, since it is well adapted to the edafoclimatic conditions of the livestock of that region. Nevertheless, there is not documented information regarding its management. Therefore, the objetive of the present study was to asses the influence of the defoliation frequency and cutting height on forage yield and nutritive quality of Z. formosa.

Materials and methods

The study was undertaken in the Zulia state, Venezuela. The experimental site is located on the town Jesus Enrique Lossada, in the livestock region El Laberinto, at 10°30’,11°00’ LN y 72°00’, 72°30’ LO at 10 msnm (COPLANARH, 1974). Mean annual rainfall ranges from to 900 to 1200 mm, with a bimodal distribution (April to June and September to December). Monthly mean annual maximum and minimum temperature is 36 and 22°C, respectively (MAC, 1968). The vegetation climax of the region is a tropical dry forest. Main grass is guinea grass. Soils are classified as Ultisol and Alfisol, with a pH of 6 and low mineral content.

Treatments and experimental design

Three defoliation frequencies (6, 8 and 10 week interval) and two cutting heigh (40 and 80 cm) were evaluated from May 1998 to April 1999. A randomized block design with three repetitions was used. Treatments were arrange in a split plot, where the cutting height was designed to the main plots and defoliation frequencies to the split-plots. A total of main plot eighteen of 61.5 m2 which were divided into three sections of 20.5 m2 each with trees spaced 1m apart both within and between rows (10 000 plants ha-1). Seeds of Z. formosa were sowed in poly-bags and then transplanted in the different plots, the period of establishment was about ten months. During the whole experimental period, weeds were controlled manually and with herbicides.

A total of four plants per split-plot was harvested, by cutting them down to 0.40 and 0.80 m above the soil, according to the frequency of defoliation. Before cutting, plant height and number of shoots were determined from each of the four harvested plants. Harvested forage was weighed and separated in fine fraction (leaf and stem < 6 mm of diameter) and gross fraction to determine dry matter (DM) percentage in both components and chemical composition, crude protein (Kjeldahl), FDA, FND and Lignin (Van Soest, 1967). Data were submitted to an analysis of variance using (SAS, 1982). Means were compared with Tukey procedure.

Results and discussion

There was a significant (P<0.05) interaction between cutting height and defoliation frequency on dry matter yield of fine fraction (YDMFF). The dry matter yield of the gross fraction (YDMGF) was not significantly affected (P<0.05) for cutting height and defoliation frequency. The YDMFF of Z. formosa increased with cutting intervals. The 6 weeks harvest regime gave significantly lower yield (P<0.05) than both 8 and 10 week regimes. This increasing of YDMFF was greater with a cutting height of 80 cm than a cutting height of 40 cm above the ground level (Fig. 1). Similar results were found in Leucaena leucocephala and Gliricidia sepium (Adejumo and Ademosun,1985; Clavero et al., 1999), where the lower dry yields associated with shorter intervals between cuttings seemed to be related to the increased number of lag recovery phases, during which the rate of dry matter production was very low.

Fig. 1. Interaction between cutting height and defoliation frequency on yield of dry matter of fine fraction.

The YDMFF registered an increasing when defoliation intervals were greater. The best defoliation frequency was on 10 week regime with a height of 80 cm and 239.70 g/plant. The YDMFF also increased with increasing cutting height. This may related to better root development, increased number of potential sites from which growth can take place, higher residual photosynthetic area left after defoliation and/or greater light interception credited to taller stubbles (Catchpoole and Blain, 1990; Faría et al., 1998). Cutting height affected significantly (P<0.01) the plant height. The cutting height of 80 cm totalled the highest growth of the plant with 115.03 cm than cutting height of 40 cm which obtained 82.68 cm. The number of shoots was affected significantly (P<0.01) by interaction between cutting height and defoliation frequency (Fig. 2). A high intensity of defoliation decreased the number of shoots since the defoliation interval decreased too. A low cutting height of the shrub legumes reduced the substance of reserves and the rate of growth of plants (Clavero, 1991; Carrete et al., 1993). With cutting height of 80 cm, the number of shoots increased when cutting intervals were longer compared with a cutting height of 40 cm. The cutting height and defoliation frequency did not affect significantly (P<0.05) the chemistry composition of PC, FDA, FND and Lignin, which were 23.48 %, 15.76 %, 28.36 % and 4.56%, respectively. Similar results were obtained in Z. formosa (Newman et al., 1999).

Fig. 2. Interaction between cutting height and defoliation frequency on number of shoot.

Conclusion

The growth and development of Z. formosa was affected by the cutting height and defoliation frequency. The best YDMFF, number of shoots and plant height were obtained when defoliation intervals were of 10 weeks with a cutting height of 80 cm. Z. formosa is a forage with definitive potential to improve the feed quality of livestock because its well adaptation with high yield of dry matter and nutritive quality. Further studies are required to determine its influence on animal performance.

References

Adejumo, J.O.; Ademosun, A.A. (1985) Effects of planting distance, cutting frequency and height on dry matter yield and nutritive value of Leucaena leucicephala sown alone in mixture Panicum maximun. Journal of Animal Production. Research. 5(2):209-221.

Carrete, F.; Equiarte, J.; Sánchez, R. (1993) Comparación de cuatro alturas de cortes en la producción y calidad del forraje de dos variedades de Leucaena. Técnica Pecuaria de México. 31(2):122-127.

Catchpoole, D.W.; Blair, G. (1990) Forage Tree Legumes. I Productivity and N economy of Leucaena, Gliricidia, Calliandra and Sesbania and Tree/Green Panic Mixtures. Australian Journal of Agriculture Research. 41:521-530.

Clavero, T. (1991) Consideraciones fisiológicas en el manejo de los forrajes, defoliación, fertilización y rebrote. En: I Curso sobre Producción e Investigación en Pastos Tropicales. Maracaibo, Venezuela. pp. 17-24.

Clavero, T.; Razz, R.; Rodríguez, A.P. (1999) Efecto de la densidad de siembra y la frecuencia de corte sobre la producción de biomasa y energía bruta en Gliricidia sepium. Revista de la Facultad de Agronomía. Universidad del Zulia. 16(1):226-240.

COPLANARH (Comisión de Plan Nacional de Aprovechamiento de los Recursos Hídricos) (1974) Inventario Nacional de Tierras. Región del Lago de Maracaibo, Venezuela.

Faría, J.; Morillo, D.; González, R.; Faría, N.; Chirinos, Z. (1998) Efecto de la frecuencia de defoliación en la producción de materia seca de Centrosema macrocarpum y Centrosema pubescens. Revista Científica, FCV-LUZ, Vol. VII, Suplemento 1:72-74.

M.A.C. (Ministerio de Agricultura y Cría) (1968) Zonas de Vida de Venezuela. Memorias Explicativas sobre el Mapa Ecológico. Caracas.

Newman, Y.; Delgado, H.; Zambrano, J.; Sthormes, G. (1999) Zapoteca formosa (Kunth) H. Hern. Subsp. Formosa: Nueva especie forrajera arbustiva natural para Venezuela. I. Estudio de fenología y contenido nutricional. Revista de la Facultad de Agronomía. Universidad del Zulia. 16:196-203).

SAS (1982) SAS User's Guide: Statistics 4th ed. SAS Institute INC Cary, NC. USA. 956p.

Van Soest, P.J. (1967) Development of a comprehensive system of feed analysis and its applications to forages. Journal of Animal Science. 26:119-125.

Nutritive assessment of Gliricidia sepium (JACQ.) KUNTH EX WALP. foliage and its effects on rumen environment

Redimio M. Pedraza Olivera[197]

Key words: browse, chemical composition, legume, ruminants.

Introduction

Gliricidia sepium is a classical example of a multipurpose tree; in some regions this specie seems to be a substitute for Leucaena leucocephala (McDicken and Raintree, 1992). The potential of its foliage in animal nutrition has been recognised (Nochebuena and O'Donovan, 1986), nevertheles, research on some aspects of its chemical composition and the effect on rumen enviroment are not abundant. The aim of this work is to distinguish the merits and nutritive limitations of G. sepium foliage, particularly those related to its chemical composition, rumen degradability and the effect on rumen environment.

Materials and methods

Sampling scheme

Compose samples of leaves (L) and petioles (P), including or not stems (S), from more than 10 trees of Gliricidia sepium were collected at different times and places; Cape Coast, Ghana (5°, 05' NL and 1°, 13' WL), Havana province, Cuba (22°, 55' NL; 82°, 01' WL), Camagüey province, Cuba (21°, 23' NL; 78°, 59' WL). Samples are indentified by its collection places, components (L, P and/or S) and age of regrowth.

Chemical composition

Proximate analysis, minerals, volaty fatty acids and ammonia were determined according to AOAC (1995) methods. Amino acids (Llames and Fontaine, 1994) and sugars (Englyst and Cummings, 1984) composition were also analysed.

Rumen degradation

Dry matter (DM) and nitrogen (N2) rumen degradation analysis were carried out according to the nylon bag procedure (Meherez and Ørskov, 1977), using rumen fistulated sheeps fed on forage diets. The data were fitted to the exponential equation: p = a + b (1 - e-ct) (Ørskov and McDonald, 1979)

In vitro gas production

Determination was completed by procedure described by Menke and Steingass (1988). Browse samples, both original foliage and original foliage plus polyethyleneglycol (PEG) 4000 were introduced into 100ml calibrated glass syringes with 30ml rumen fluid-buffer solution; the contribution in gas of the soluble and insoluble fractions was determined by incubating separetly water insoluble residues and samples without washing.

Experiments on rumen environment

The in vitro study was carried out by using three G. sepium: Cynodon nlenfluencis dryed samples proportions (0:100, 15:75 and 30:70%, respectively) incubated at 39° C with rumen fluid during 24 hours. Culture techniques were developed according to the general procedures described by Hungate (1970). Two in vivo studies were developed: in the first, were used three rumen fistulated bulls according a group-period design, the animal were fed on fresh King Grass (Pennisetum purpureum x Pennisetum typhoides) and recieved 0.5kg of soya meal or 1kg DM intracannula of G. sepium fresh leaves and petioles. In the second study were used four rumen cannulated sheeps in an incomplete 4x4 latin square design. The animal were fed on barley straw plus urea (22g of degradable N2/kg Degradable Organic Matter) and vitamins-minerals supplement mixture; treatments were 9, 6, 3, or 0g of G. sepium foliage’s sun dried mill offered for kg W0.75. Forage standars were rumen incubated in both experiments; rumen liquid samples were taken for chemical analysis and protozooa counting.

Statistical procedure

ANOVA and regression analysis were developed; differences between means were determined according Tukey test. All statistical procedures were done by using SYSTAT 7.0 statistical package.

Results

The chemical composition in a Camagüey cultivar showed better values in the leaves - petioles fraction (Table 1). The increase of the crude fiber with age influences negatively the nutritive value; after 120 days of regrowth the crude fiber contents became higher, mainly in whole foliage.

Table 1. Chemical composition of G. sepium foliage at different regrowth ages (% DM).

Days

Whole foliage

Leaves+petioles

60

90

120

180

±SE

60

90

120

180

±SE

Dry Matter, %

19.6c

26.0b

36.7ª

37.7ª

1.6***

27.5ab

28.7ª

24.6b

26.5ab

1.0***

Crude Fiber

28.4c

31.6b

33.5ab

35.5ª

0.9**

23.3b

26.1ª

27.4ª

27.2ª

0.6*

Crude Protein

20.4ª

18.8ª

15.1b

14.7b

0.7***

21.7a

19.4ab

17.2bc

16.3c

0.6***

Ca

1.6ª

1.5ª

1.5a

1.2b

0.1**

1.5 6

1.7 0

1.7 9

1.4 7

0.0 6

P

0.2b

0.1b

0.3a

0.2ab

0.1*

0.12

0.16

0.20

0.24

0.02

Cu

10.0

11.0

7.0

5.0

0.9

9.0

7.0

6.0

5.7

0.5

Co

2.0

2.0

2.3

1.3

0.2

2.3

1.3

2.3

1.7

0.2

Fe

17.0

23.0

18.0

13.0

1.9

52.0a

18.0b

29.0b

15.0b

5.3*

* P< 0.05 ** P<0.01 *** P <0.001

All the samples have a total nitrogen content superior to 2% in the DM; as a rule, the fractions L+P and with smaller ages of regrowth have the greater concentrations. The amino acids in greater proportion in the leaves + petioles of Havana and Ghana cultivars (Table 2) are glutamic and aspartic acids, while methionine and cystine are found in smaller concentration.

Table 2. Contents of some ammino acid and sugar in the L+P of two contrasting G. sepium cultivars.

Amino acids (AA)

Sugars

AA, g/16 g N2

Cv. Ghana

cv. Havana

Pooled SD

Sugar, g kg DM-1

cv. Ghana

cv. Havana

Pooled SD

Glu

9.70

8.89

0.58

Rhamnose

16.5

21.5

0.7

Asp

7.34

8.77

0.85

Fucose

2.0

2.5

0.1

Leu

7.20

6.05

0.38

Arabinose

17.5

24.5

0.5

Lys

4.86

4.05

0.21

Xylose

18.5

27.5

0.5

Ile

4.01

3.80

0.62

Manose

8.5

10.5

0.3

Pro

3.62

3.56

0.19

Galactose

24.0

26.0

0.5

Cys

1.36

0.98

0.10

Glucose

117.0

122.0

4.3

Met

0.61

0.52

0.11

Uronic acid

51.0

72.0

0.8

The greater value of sugars concentration in both G. sepium foliage studied belongs to the glucose, the smaller concentration corresponds to the fucose (Table 2). The DM and nitrogen rumen degradability paramenters (Table 3) showed the hight values in all studied samples. The degradable fraction at zero time had the greatest variability, while degradation rates were less variable.

Table 3. Parameters of dry matter and nitrogen rumen degradability (5 samples studied).

Dry Matter

Nitrogen

Parameter

Min.

Max.

Average

CV

Min.

Max.

Average

CV

a, %

9.0

35.3

23.5

47.3

0.5

22.6

14.9

60.5

b, %

37.1

64.3

48.7

26.5

58.7

81.2

66.8

16.2

c, % h-1

0.070

0.099

0.088

14.4

0.063

0.104

0.077

21.3

a- degradable fraction at zero time, b- insoluble but fermentable fraction, c- degradation rate.

Table 4. In vitro gas production of both soluble and insoluble fractions of G. sepium foliages (ml).

 

Leaves+Petioles+Stems 60 days, Havana

Leaves+Petioles 60 days Havana

Leaves+Petioles+Stems 100-120 days Camagüey

Fraction


Fraction


Fraction


Incubation time

Insoluble

Soluble

± SE

Insoluble

Soluble

± SE

Insoluble

Soluble

± SE

12h

10.9a

11.5a

0.4

8.5b

12.0a

0.8

7.9ª

4.5b

0.8

48h

18.9ª

14.1b

1.2

17.9ª

14.5b

0.8

16.1ª

4.7b

2.6

The greater in vitro gas production occurs in the smaller age of regrowth foliages, despite if they includ stems. There are not significative differences (P>0.05) in the gas production accumulated to 6, 48 and 96 hours with and without the use of the PEG 4000. The results in Table 4 suggest that the soluble or quickly degradable fraction of G. sepium foliage it is not fermented totally at 0 time, on the contrary it accomplishes an important energetic contribution during the first hours after incubation; new research on the nutritive meaning of this fraction is necesary.

Table 5. Some indicators of rumen environment in vitro incubating three Cynodon nlenfluencis: G. sepium dryed sample proportions.


Proportions Cynodon nlenfluencis: G. sepium, %


Indicadores

100:0

85:15

70:30

± SE

Total bacteria, 1011 colonies/ml

1.85 (70.79)

1.90 (79.43)

1.43 (76.92)

0.42

Celulolitic bacteria, 106 colonies/ml

0.83a (6.31)

0.90a (7.94)

1.14b (13.90)

0.14**

Celulolitic fungi, 106 colonies/ml

0.87ª (7.41)

0.92ª (8.34)

1.19b (15.53)

0.29*

Total protozoa, 106 cell/ml

1.60ª (5.83)

0.92b (3.31)

0.04c (1.48)

0.11***

- Data transformed, original data between parenthesis.

The total volaty fatty acids concentration and their proportions were not seen affected by the inclusion of G. sepium foliage. The celulolitic bacteria increased its population (P<0.01) when G. sepium was included at 30%, as well as celulolitic fungi (P<0.05). It was observed a reduction of protozoa population using 15 and 30% G. sepium (Table 5). The NH3 concentration in the rumen reached values from 130.7 to 182.7mg/L in the animals that recieved 1kg DM intracannula of G. sepium fresh leaves and petioles, while the volaty fatty acids and protozoa concentration, as well as forage standard degradation, tended to be similar to those animals supplemented with 0.5kg of soya meal. G. sepium foliage’s sun dried mill (15.0% Crude Protein) intake lower to 6.3g DM/kg W0.75/animal/day, and when easy degradable nitrogen was not limited, there were not showed additional beneficial effects on rumen environment.

Discusion

The higher nutritive value of Gliricidia sepium foliage is found in the fraction leaves - petioles and at smaller ages of regrowth. The nutritive value of this legume can be compared to that as the leucaena, clover and alfalfa (McDonald et al., 1995; Abdulrazak et al., 1996). In all the ages, both the whole foliage and leaves - petioles, were found protein values very superior to those described by Martín (1998) for 15 genus of grasses usually used in the tropic; this reafirms the potential of G. sepium as an option as supplement in many low quality tropical ruminant diets. The high potential of nitrogen degradability indicates the great capacity of G. sepium foliage as source of nitrogen to the rumen ecosystem. The contribution of both water soluble and insoluble fractions of the foliage confirms partially the results of some feeding trials (Pathirana and Ørskov, 1995; Abdulrazak et al., 1996) that attribute G. sepium the property of supplying easily fermentable fiber. D'Mello (1992) considers the antinutritive substances as the major limiting to increase the use of the tropical legumes in animal nutrition, nevertheles the use of PEG 4000 demonstrated that tannins do not make a negative effect on the nutritive value of this foliage. The nutritive value of G. sepium foliage, measured by its in vitro gas production, can surpass that of forages of very good quality as L. leucocephala, Trichantera gigantea and others (Tuah et al., 1996; Blümmel and Becker, 1997). The behavior of in vitro and in vivo populations of protozoa, did not show consistent results on a possible defaunating activity in this browse, so this topic deserve more research work. The levels of NH3 in rumen using G.sepium fresh foliage were sufficient to guarantee an adequate rumen DM degradability and can assure a good voluntary intake by the ruminants Hogan (1996).

Conclusions

The value of G. sepium foliage as supplement is based mainly on the supply of degradable nitrogen and organic matter to the rumen ecosystem. It is convenient to differentiate the use of the whole foliage or its leaves - petioles fraction according to age of regrowth.

Acknowledgments

Thanks are due to the International Foundation for Science (Project B/1732-2), the University of Camagüey and Animal Science Institute (ICA), Cuba; as well as to the International Feed Resources Unit (IFRU) at Aberdeen, UK.

References

Abdulrazak, S. A., Muninga, R. W., Thorpe, W. and Ørskov, E. R. (1996). The effects of supplementation with Gliricidia sepium or Leucaena leucocephala forage on intake, digestion and live-weight gains of Bos taurus x Bos indicus steers offered Napier grass. Animal Science. Vol 63 (3). pp. 381-388.

AOAC (Association of Official Analytical Chemist). (1995). Official Methods of Analysis. 16th Edition. Association of Official Analytical Chemist. AOAC International. Washington, DC.

Blümmel, M. and Becker, K. (1997). The degradability characteristics of fiftyfour roughages and roughage neutral-detergent fibre as described by in vitro gas production and their relationship to voluntary feed intake. British Journal of Nutrition, 77. pp. 757-768.

D'Mello, J. P. F. (1995). Anti-nutritional substances in legume seeds. In: Tropical Legumes in Animal Nutrition (ed. D'Mello, J. P. F. and Devendra, C.), CAB International, Wallingford, UK. pp. 135-172.

Englyst, H. N. and Cummings, J. H. (1984). Simplified method for the measurement of total non-starch polysaccharides by gas-liquid chromatography of constituent sugars and alditol acetates. Analyst 95. pp. 181-193.

Hogan, J. (1996). Feed intake. Ruminant Nutrition and Production in the Tropics and Subtropics. Bakrie, B., Hogan, J., Liang, J. B., Tareque, A. M. M. and Upadhyay, R. C. (eds.). ACIAR Monograph No. 36, pp. 47 - 58.

Hungate, R. E. (1970). A roll tube method for cultivation in microbiology. J. B. Morris and D. B. Ribbons (Eds.). New York Academic Press Inc., pp.117.

Llames, C. R. and Fontaine, J. (1994). Determination of amino acids in feeds: Collaborative study. J. AOAC Int., 77: pp. 1362-1402.

Martín, P. C. (1998). Valor nutritivo de las gramineas tropicales. Rev. cubana Cienc. agríc., 32 (1), pp. 1-10.

McDicken, K. G. and Raintree, J. B. B. (1992). An overview of multipurpose tree species. Research on multipurpose tree species in Asia. Procedings of an International Workshop held Nov. 19-23, 1990, Los Baños, Philipines. Editors: D. A. Taylor and K. G. MacDicken. IFS. Winrock International Institute for Agricultural Development, Thailand. pp. 5-10.

McDonald, P., Edwards, R. A., Greenhalgh, J. F. D. and Morgan, C. A. (1995). Animal Nutrition. Fifth Edition. Longman Scientific and Technical. pp. 546-563.

Mehrez, A. Z. and Ørskov, E. R. (1977). A study of the artificial fibre bag technique for determining the digestibility of feeds in the rumen. J. Agric. Sci., 88: 645-650.

Menke, K. H. and Steingass, H. (1988). Estimation of the energetic feed value obtained from chemical analysis and in vitro gas production using rumen fluid. Animal Research and Development. Vol. 28, pp. 7-55.

Nochebuena, G. and O'Donovan, N. (1986). Valor nutritivo del follaje rico en proteína de Gliricidia sepium. Revista Mundial de Zootécnia, 57: 48-4.

Ørskov, E. R. and McDonald, I. (1979). The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. J. Agric. Sci., 92: 499-503.

Pathirana, K. K. and Ørskov, E. R. (1995). Effect of supplementing rice straw with urea and gliricidia forage on intake and digestibility by sheep. Livestock Research for Rural Development, Vol. 7, No. 2.

Tuah, A. K., Okail, D. B., Ørskov, E. R., Kyle, D., Shand, W., Greenhalgh, J. F. D., Obese, F. Y. and Karikari, P. K. (1996). In sacco dry matter degradability and in vitro gas production characteristics of some Ghanaian feeds. Livestock Research for Rural Development. Vol. 8, No. 1.

Agronomic study of silvopastoral system Cynodon nlemfuensis-Leucaena leucocephala with sheep

J. G. Escobedo-Mex[198], L. Ramírez-Avilés[199], V. R. Chan-Poot[200]

Key words: Cynodon nlemfuensis, Leucaena leucocephala, sheep, yield

Introduction

Animal production in the tropical regions of Mexico is based on grasslands under grazing conditions, which have low productivity (Koppel et al., 1999). This type of production systems has reduced the areas of natural vegetation, which damage the ecology (flora, fauna and soil). In view of this, it is important to implement silvopastoral technologies as promising tools to improve the welfare and economic conditions of rural population and, consequently, to preserve their natural resources (Nair, 1997; Krishnamurthy and Avila, 1999; Murgueitio et al., 1999). The current work, was designed to assess the introduction of Leucaena leucocephala under silvopastoral systems on Cynodon nlemfuensis grazed by sheep.

Materials and methods

The present experiment was carried at the Instituto Tecnologico Agropecuario 2, located at Conkal (20º 59’ North Latitude, 89º 39’ West Longitud), Yucatan, Mexico. The climate of the area is Awo with a mean annual rainfall and temperature of 850 mm and 26.5 oC, respectively. Soils are classified as Lithosols with pH of 7-8 (Duch-Gary, 1988). The experiment was conducted from September 1999-February 2000. A completely randomized design with three repetitions and a factorial arrangement (2x2) were used. The experimental factors were: Systems T1) Star grass alone, and T2) Star grass + L. leucocephala cv. Peru. These treatments were evaluated during two seasons (i.e. Late-rainy and Dry seasons). Availability of green dry matter (GDM), percentage of leaf, stem and dead material of the forage grass, and daily liveweight gain (DLG) of Pelibuey sheep were determined. Availability of forage grass was determined by cutting ten quadrants of 0.25 m2/paddock, located at random in each experimental paddock. L. leucocephala green forage was determined by cutting six plants selected at random in the central rows of the paddocks. Experimental paddocks were of 525 m2 in size, which were rotationally grazed, with 7/28 days of graze and rest periods, respectively, during the late-rainy season, and 5/35 days graze and rest periods, during the dry season, the grazing cycles were 16. Experimental paddocks were not fertilized. Star grass was sown 15 years ago, and rows of Leucaena were planted into star grass 3 m apart and 50 cm between plants, after planting, Leucaena allowed to grow for one year and then cut down to 0.50 m, subsequently, it was cut every three months during the following year and was grazed by sheep. Twenty four male sheep young (Pelibuey) were used, which were treated against parasites, vaccinated and weighed. Experimental data were submitted to an analysis of variance using SAS (SAS, 1985). Treatment means were compared by Tukey test.

Results

In the Figure 1 the trends of GDM yield are shown, in the late-rainy season was greater (P< 0.0001), with 2678 kg GDM/ha, than, in the dry season with 2272, respectively. The GDM was lower (P<0.01) with T1 than with T2, 2350 and 2600 kg/ha, respectively. The leaf:stem index was significantly (P<0.001) lower during late-rainy season than in the dry season, 0.28 and 0.39, but was similar (P>0.05) in both Systems.

Figure 1. Availability of Green dry matter (GDM) from Star grass (Cynodon nlemfuensis) alone and Silvopastoral systems (SS) grazed by sheep in Yucatan, Mexico.

Some agronomic characteristics of L. leucocephala are shown in Table 1. It can be observed that, at the beginning the trial, the Leucaena was at the flowering phase, which is demonstrated with high values of flowers and pods observed after cutting. It is important to note the high number of branches of L. leucocephala. Therefore, it can be easily consumed by sheep. The stem diameter was similar in both seasons.

Table 1. Means of some agronomic characteristics of Leucaena leucocephala grazed by sheep in Yucatan, Mexico.

Season

Diameter at 20 cm (cm)

Number of secondary branches

Number of floral buttons

Number of flowers

Number of pods

Late rainy

3.155

6.5

1.7

11.5

6.2

Dry season

3.132

4.9

7.7

0.6

2.9

The DLG of Pelibuey sheep was 29 and 46 g for T1 and T2, respectively (P<0.01). But was similar the DLG (P>0.05) between both seasons.

Discussion

The low GDM yield contribution of L. leucocephala to SS was, perhaps, a result of the edhafic and climatic conditions of the experimental paddocks (Duch-Gary, 1988) where carried these essay. In addition, the regime of cutting used affected the legume yield. Similar information was found by Román-Miranda (1997). The daily liveweight gain of Pelibuey sheep was higher in SS. In this respect, Alayon et al. (1998) found a positive effect of Gliricidia sepium as a supplement to low quality Star grass (C. nlemfuensis) hay upon dry matter, organic matter and crude protein intake, when used Pelibuey sheep. Then, it is possible to hope a similar effect when use Leucaena in SS agrees with results of others (Ku-Vera et al., 1999). Nevertheless, the low GDM yield results in low daily liveweight gain under grazing conditions. It is important to emphasize that, the benefit of the use any legume tree in silvopastoral systems is reached in a long period.

Conclusions

The incorporation of L. leucocephala under a silvopastoral systems with C. nlemfuensis grasslands has a limited contribution to green dry matter of forage biomass during the late-rainy season and, consequently, it has low the daily liveweight gain of Pelibuey sheep under the edhafic and climatic conditions at Yucatan, Mexico. However, it is possible that Leucaena could contribute to agroecosistem on a long-term in the dry seasons, mainly to improve soil conditions.

Acknowledgements

J. A. Escobedo-Mex is grateful to Consejo Nacional de Ciencia y Tecnologia (CONACYT, Mexico) for the award of a post-graduate (Ph.D.) scholarship at the Faculty of Veterinary Medicine and Animal Production, University of Yucatan. The authors are grateful to IFS (Sweden), CoSNET (Mexico) and to CONACYT (31661 B) for providing funds that allowed to carry out the present study.

References

Alayón JA, Ramírez-Avilés L and Ku-Vera JC (1998) Intake, rumen digestion, digestibility and microbial nitrogen supply in sheep fed Cynodon nlemfuensis supplemented with Gliricidia sepium. Agroforestry Systems 41: 115-126

Duch-Gary J (1988) La conformación territorial del Estado de Yucatán. Los componentes del medio físico. Universidad Autónoma Chapingo. Centro Regional de la Península de Yucatán. México, D.F. pp. 295-395

Koppel-Rizo ET, Ortíz-Ortíz GA, Avila-Durán A, Lagunes-Lagunes J, Castañeda-Martínez OG, López-Guerrero I, Aguilar-Barradas U, Román-Ponce H, Villagómez-Cortés JA, Aguilera-Sosa R, Quiróz-Valiente J and Calderón-Robles RC (1999) Manejo de ganado bovino de doble propósito en el trópico. INIFAP-CIRGOC. Libro Técnico No. 5. Veracruz, México. 158 p

Krishnamurthy L and Avila M (1999) Agroforestería básica. Serie Textos Básicos para la formación Ambiental. Programa de la Naciones Unidas para el Medio Ambiente (PNUMA). Oficina Regional para América Latina y el Caribe. México, D.F. 340 p

Ku-Vera JC, Ramírez-Avilés L, Jiménez-Ferrer G, Alayón JA and Ramírez-Cancino L (1999) Árboles y arbustos para la producción animal en el trópico mexicano. In: Sánchez MD and Rosales M (eds) Agroforestería para la producción animal en América Latina. Estudio FAO Producción y Sanidad Animal No. 143. Roma, Italia. pp. 231-250

Murgueitio RE, Rosales MM and Gómez ME (1999) Agroforestería para la producción animal sostenible. CIPAV. Cali, Colombia. 67 p.

Nair PKR (1997) Agroforestería. Centro de Agroforestería para el Desarrollo Sostenible-Universidad Autónoma Chapingo. Chapingo, México. 543 p

Román-Miranda ML (1997) Determinación de altura inicial al pastoreo de Leucaena leucocephala en un banco de proteína para ovinos. Tesis de Maestría. Facultad de Medicina Veterinaria y Zootecnia. Universidad de Colima. Colima, México. 76 p

SAS (1985) SAS User's Guide. Statistics. 5th ed. SAS Institute Inc. Cary, NC. USA. 956 p

The use of fruit and forage of woody species in livestock production systems in Boaco, Nicaragua

Sheyla Zamora Lopez[201], Jeymi Garcia[202], Glenda Bonilla[203],
Holmes Aguilar[204], Celia Harvey[205] and Muhammad Ibrahim[206]

Introduction

In Nicaragua, livestock production systems are often limited by the shortage of fodder during the dry season and by the inappropriate management of pastures and cattle. In order to overcome forage shortages, livestock farmers are beginning to manage the woody plants in their pastures as sources of fodder and fruits for cattle during the dry season. Although woody species hold potential for improving cattle production during the dry season, there is little information available on which woody plants provide forage and fruits suitable for cattle consumption, how farmers manage woody plants, and how farmers prepare and store different forages and fruits.

In this study, we document how farmers in Boaco, Nicaragua, manage and use the woody plants present in their pastures to provide fruits and forage to cattle during the dry season. The specific objectives of this study were:1) to conduct surveys of the abundance and diversity of woody plants in pastures; 2) to document farmer knowledge about the use of woody plants for cattle production; and 3) to identify the technologies used to process woody plant fruits and forage so that they may be fed to cattle. As the study is ongoing, the data presented here are preliminary.

Methods

The study was conducted in the department of Boaco (including the municipalities of Teustepe, Boaco, San Lorenzo and Camoapa) which is one of the largest cattle-producing regions of Nicaragua. The department of Boaco is located at an elevation of 2200 ft (12º 25’N, 85º30’ W), and receives an annual rainfall of 900-2000 mm/year.. Livestock farms are generally large (50- 250 ha), and are managed extensively (with few or no inputs). The cattle are dual purpose and are mixes of Brahman, Jersey, Holstein, Santa Gertrudis, Reina, and Swiss Brown. In the dry season where grass is scarce, farmers either move their cattle to the mountains or sell cattle for meat production to diminish herd size.

To assess the abundance and diversity of woody species in the pastures, we surveyed the density and diversity of wood species in pastures on 10 randomly-selected farms. In each farm we established 4 perpendicular transects, each 500 m long and 20 m wide (0.1 per transect; 4 transects = 0.4 ha/farm), forming the shape of a cross. In each of the transects we counted, identified and measured (dbh, height) all woody plants > 1.5 m in height.

In order to document farmer knowledge of the use of woody species as forage for cattle, we conducted semi-structured interview with 30 cattle farmers (selected randomly from a list of 250 cattle farmers in the region). Farmers were asked about the use and management of woody species in their pastures, the woody species that are suitable for cattle consumption, and the use and preparation of forage and fruits from woody species.

Results

Livestock production system

The cattle farms in the Boaco region have an average of 76 cows (dual-purpose), with a range from 8-300/farm. Milk production is highly seasonal, with milk yields being significantly greater in the wet season (mean daily production of 4 liters/cow) than in the dry season (mean daily production of 2.5 liters/cow). In the dry season, milk yields are reduced by an average of 40% (SE = 22.1%), with some farms experiencing reductions of up to 71%.

Trees in pastures

A total of 692 trees were surveyed in the pastures representing 25 tree species (Table 1). Of these species, the most common species were Guazuma ulmifolia (16% of all trees found), Bursera simarouba (15.1%) and Cordia alliodora (9.9 %).

Woody species that offer forage and fruits to cattle

According to the farmers, there are a total of 21 woody species in their pastures that provide forage to livestock and 16 woody species that provide edible fruits for cattle (Table 1). The most-frequently mentioned forage species were Gliricidia sepium (mentioned by 26 of the 30 farmers), Guazuma ulmifolia (23 farmers), Pithecellobium saman (10 farmers) and Enterolobium cyclocarpum (9 farmers). With the exception of Gliricidia sepium, the same species were also the most important species for fruit production. It interesting to note that the most abundant tree species, Guazuma ulmifolia, provides both fruits and forage to cattle.

Many of the trees in pastures have additional value as sources of timber (e.g., Laurel, Guanacaste, Genizaro, Roble, Güiligüiste, Coyote, Granadillo, Cedro, Aceituno, Tempisque) firewood (Guacimo, Tiguilote, Melero, Nacacola, Quebracho, Madero Negro, Carbon, Chiquirin, Frijollio, Leucaena Tempisque, y Vanillo), material for fence posts (Madero Negro, Guacimo, Helequeme, y Guiliguiste) and other products.

Use of tree forage

Although trees are common in the Boaco pastures, few farmers actively manage trees or process forage and fruits to feed their cattle. The majority of the farmers simply allow their cattle to browse on the tree foliage that is within their reach. However, a subset of farmers, periodically cut the branches and leaves of woody species in the pastures so that the cattle can feed directly on the fallen, fresh leaves. A even smaller number of the farmers actively manage tree foliage and fruits, and use them to supplement their cattle diets.

Table 1. Abundance and densities of the most common tree species present in pastures of 10 cattle farms in Boaco, Nicaragua. Tree species are listed in descending order of abundance.

Species

Common name

Total # of individuals

% of all trees (of 692 total)

Number of farms in which present (of 10 possible)

Average number of trees per farm

Source of forage for cattle?**

Source of fruits for cattle?**

Guazuma ulmifolia

Guácimo

113

16.3

9

11.3

23

27

Bursera simarouba

Jiñocuabo

105

15.1

5

10.5

6


Cordia alliodora

Laurel

69

10.0

5

6.9



Cordia dentata

Tiguilote

58

8.4

2

5.8

3

4

Hippomane mancinella

Manzano

49

7.1

1

4.9



Tabebuia rosea

Roble

40

5.8

3

4



Byrsonima crassifolia

Nancite

37

5.3

2

3.7

2


Platymiscium pleiostachyum

Coyote

29

4.2

2

2.9



Gliricida sepium

Madero Negro

28

4.0

3

2.8

26

1

K arwinskia calderonii

Güiligüiste

26

3.8

3

2.6



Pithecellobium sp.

Espino de playa

25

3.6

2

2.5

1


Thouinitium decandrum

Melero

21

3.0

1

2.1



Platymiscium pinnatum

Granadillo

15

2.2

1

1.5



Pithecellobium saman

Genízaro

13

1.9

1

1.3

10

23

Caesalpinea coriaria

Nacascolo

12

1.7

1

1.2


1

Inga sp.

Guaba

11

1.6

1

1.1

1


Cassia grandis

Carao

7

1.0

1

0.7



Lysiloma sp.

Quebracho

6

0.9

1

0.6

1


Crescentia alata

Jicaro

6

0.9

1

0.6


3

Ficus sp.

Chilamate

5

0.7

1

0.5

2

3

Sciadodendron sp.

Jobo

4

0.6

1

0.4



Enterolobium cyclocarpum

Guanacaste

4

0.6

1

0.4

9

22

Cedrela odorata

Cedro

3

0.4

1

0.3



Hymenaea courbaril

Guapinol

3

0.4

1

0.3



Spondias mombin

Jocote

3

0.4

1

0.3

1

1

Simarouba glauca

Aceituno*





1


Acacia pennatula

Carbon*





1


Myrospermum frutescens

Chiquirin*





2


Leuceana shannoni?

Frijollillo*





1

1

Citrus sp.

Grapefruit*






1

Psidium guajava

Guayaba*






2

Erythrina sp.

Helequeme*





7


Leucaena leucocephala

Leucaena*





6


Mangifera indica

Mango*






1

Citrus sp.

Naranja*






2

Mastichodendron capiri

Tempisque*





1

1

?

Vainillo*






1

Acacia glomerosa?

Zarcillo*





3



Total # of trees surveyed:

692



Total # species

21

16

*These tree species were mentioned by farmers as being present in their farms, but were not recorded in the pasture sites surveyed.

** The numbers reflect the number of farmers who mentioned the use of this woody species for forage and/or fruit (out of 30 farmers total).

One way in which farmers may supplement their cattle diets is by making silage out of the leaves of Gliricidia sepium, Enterolobium cyclocarpum, Pithecellobium saman, and Taiwan grass. The Taiwan grass is allowed to grow for 45 days and is then cut and chopped into small pieces; the foliage of the tree species is cut and similarly chopped into small pieces. To create the silage, the farmers place alternate layers of Taiwan grass and tree foliage, with each layer averaging about 2 inches in depth. Once the silo has been created, it is covered with plastic to prevent water from entering and is turned over roughly every 15 days. After 30 days of storage, the silage can be fed to the cattle. Generally, farmers provide 15 lbs of silage to each animal each day, mixing it with melaza.

Some farmers also produce hay from Gliricidia sepium, by cutting the foliage and storing it under a roof for 15 days, until it is well-dried. During the first 7 days of drying, the foliage is turned over three times a day to ensure that it dries consistently; in the final 7 days, the foliage is only moved twice a day. After 15 days of drying, the hay is stored under a black plastic tarp (to prevent it from getting wet) and is ready to be used. Farmers typically provide of 6 lbs of hay per animal per day, in combination with melaza or gallinaza.

Use of tree fruits

The majority of the farmers do not use or manage the fruits of the woody species present in their pastures, although their cattle feed on fruits that fall naturally. Only 4 of the 30 farmers surveyed collect and use fruits to supplement their cattle’s diet. The most commonly collected fruits are from Enterolobium cyclocarpum, Pithecellobium saman and Guazuma ulmifolia trees. Before feeding the fruits to the cattle, the farmers crush (pulverize) the fruits with a manual press into a fine powder that the cattle can easily digest. This mixture of fruits is provided to cows at a rate of 2-4 lbs per animal per day (without the addition of melaza or other products). During the dry season, the use of fruits to supplement cattle diets may increase milk yields up to 50% (i.e. to levels found in the wet season).

Some farmers also prepare jicaro fruits to feed their cattle. The jicaro fruits are cut from the trees when they are ripe and are stored in shade for another 10-15 days. The fruits are then broken with a spade or hammer and the flesh of the fruit is extracted and separated from the shell. This pulp can be given directly to the cattle (doses of roughly 4-5 lbs per animal/day) and can increase milk yields in cows up to 50%.

Acknowledgements

The authors thank the CATIE-DANIDA Agroforestry Project for funding this research.

Tagasaste: promisory fodder shrub for areas of subhumid mediterranean dryland

Fernando Fernández E.[207]; Carlos Ovalle M[208] y Julia Avendaño R[209],[210]

Key words: cattle, fodder shrub, forage production, ruminal degradability, sheep, Tagasaste (Chamaecytisus proliferus spp. palmensis)

Introduction

In Mediterranean areas, animal production depends on forage from annual natural pasture, which have null growth in summer and early autumn, due to lack of humidity of the soil. The nutritive requirements of the animals in this period are covered by dry grass of the natural pasture, stubbles of cereals, leguminous, and “hawthorn” (Acacia caven). The forage availability is not enough because besides it is necessary to have reserves for five or more months, situation which may worst when precipitation begin late in autumn (Ovalle et al.,1993).

This has leaded to look for species that subsist to summer drought conditions, that can be used as green forage in this critical period, can be integrated to silvopastorales systems and also that contribute with shade and nitrogen fixation. It was done a research, in order to find bushes and trees fodder, being Tagasaste the species with better performance.

Botany and ecology

Tagasaste is a fodder leguminous, always green, belongs to the family Fabaceae, subfamilia Papilionaceas, specie Chamaecytisus proliferus (L.Fil) Link ssp. proliferus var. palmensis. Native of island of The Palm, in the Spanish archipelago of Canarias. In its origin area, it grows at 500 to 1200 m.s.n.m., in an area with 500 to 700 mm of annual rainfall, that fall betwen autumn and spring, the temperature range between 5 º and 15º C in winter and betwen 20 º and 30 º C in summer (Ortega et al., 1990), similar to the dryland area of central Chile. It requires good drainage soils, with pH of 5 at 7, with textures from sandy to franc and deep (Fraga et al., 1999).

Dispersion outside of Canarias and in Chile

In the last century it was distributed to the English colonies of Australia, India and Sudáfrica through the Royal Botanic Garden. In South Australia was introduced in 1879, being quickly naturalized; however, research on its use as a forage began around 1950 (Snook, 1961). It has been planted in New Zealand, in areas with long summer droughts, without frost, in light and sandy floors (Snook, 1961).

It was introduced to Chile in 1988 from Australia, and in 1991 from New Zealand, by the Institute of Agricultural Research (INIA).However, the introduction of this specie to the country is mentioned as early as the beginning of the 20th century (Opazo, 1930).

Behavior in areas of dryland of Chile

In 1990 were carried out the first plantations, from the IV to the VIII Region; results show low survival in the premountain range because of the frost and in the arid and semi-arid area because of the low rainfall. In the subhumid area the adaptation was good, but it is necessary to irrigate during the summer on the first year (Ovalle et al., 1993). In 1995 was evaluated among VI (34º 10 S, 71º 56 W) and the IX Región (38º 30 S, 72º 37 W), in diverse climate and soils conditions, embracing the main animal production area of the mediterranean dryland. The best survival was achieved in costal areas, because of the marine effects that minimizes frost, and reduce evapotranspiration during summer (Fernández et al., 1999).

Forage production

The coastal dryland from VI to IX Region is very well adapted for plants growth, because of soil fertility and the favorable environmental conditions. In evaluations carried out in 4 year-old plantations in this area, productions of consumable dry matter, leaves and shafts smaller than 0.5 cm of diameter, ranged from 2381, 1759 and 672 kg DM ha-1 (Figure 1) (Fernández et al., 1999).

Figure 1. Evolution of the production of plants of Tagasaste during four seasons, in different areas of Mediterranean Central Chile.

Chemical composition and nutritive value

It have a high content of brut protein on the leaves (Table 1), similar to that found by Borens 1986; the content of new leaves is comparable to red clover or lucerne hay (NCR, 1984); the content of mature shafts are comparable to degraded pasture. The values of fiber acid detergent was between 19,7 and 59,7%, in the consumable and not consumable forage, these levels increase according to the plant component. The lignin content increases with maturity, its content in leaves and tender shafts range between 7.2 and 7.9%, up to 12% in ligneous shafts (Arredondo et al., 1997).

Table 1. Chemical composition of the components of the Tagasaste plant.

Component

Protein (%)

Fiber detergent acid (%)

Lignin (%)

Ash (%)

Metabolizable energy (Mcal/kg of DM)

Leaf tender

21,0 2

19,7

7,2

5,7

2,64

Leaf mature

0,3

19,8

7,3

5,0

2,64

Stalk tender

12,5

42,1

7,9

4,2

2,06

Stalk ligneous < 1 cm

6,5

55,0

11,2

2,4

1,69

Stalk ligneous > 1 cm

3,8

59,7

12,1

1,2

1,55

Source: Arredondo et al., 1997

The energy levels were between 2.6 and 2.0 Mcal kg -1 of DM for leaves and consumable shafts; these values are lower to those of lucerne hay, and they are lower in comparison with the cereals grains. The energy values of ligneous shafts are comparable to cereals straws.

The digestibility in situ using steer and measuring the degradability of the different components in a period of 72 hours is quite good, with values of 87% for mature leaves and 85% in tender leaves, values comparable to those obtained in maize silage and lucerne hay. The ligneous shafts bigger than 1 cm diameter have a lower degradability with values of 15,9% (Arredondo et al., 1997).

Management and utilization

The plant must be managed to have a height that assures good use by the animals; this is achieved with prunings. The maximum height for sheep consumption is 1,3 m; bovine calves can browse between 1,5 and 1,7 m, while mature animals can prune between 2,5 and 3 m.Both animal species reject branches with diameter in the base and apex of 4,6 and 2,8 mm, respectively, and length superior to 23 cm (Avendaño et al., 1999).

The most economic form of utilization is grazing, but it can be also supplied as soiling; in grazing the animals consume 100% of the leaves and near 70% of branches and buds.

The time of utilization with sheep will depend on the critical periods for the animal, such as mating or lambing; in the case of bovines will depend on the production system and the desired finishing period, such as breeding or fattening.

Nitrogen fixation

Tagasaste, like other woody leguminous, have an important role in restoration and rehabilitation of soil in degraded areas, being a great nitrogen fixating plant; in evaluations carried out during six seasons in a plantation of 1.666 trees ha-1 the total fixed nitrogen was 496 kg ha-1 as compared with A.caven, that only fixes 56,15 kg of N ha-1 in the same period (Ovalle et al., 1996).

Conclusions

It was evaluated the productive potential of Tagasaste in this area, in which offer forage in critical periods of deficit, as it is summer and autumn - winter. It is very well accepted by sheep and cattle, being the last more selective; nitrogen contribution to the soil is very important. In relation to forage composition, it presents a high protein content and low fiber acid detergent, especially in the leaves, which have high digestibility of the dry matter.

References

Arredondo, S; Jahn, E. y Ovalle, C. 1997. Degradabilidad ruminal de distintos componentes de la planta de tagasaste (Chamaecytisus proliferus spp. palmensis) mediante el uso de la técnica de novillos fistulados en el rumen. Agricultura Técnica (Chile). 57(2): 127-135.

Borens, F. 1986. The nutritive and feeding value of tagasaste (Chamaecytisus palmensis). Thesis Ms. Sci. Lincoln College, New Zealand University of Canterbury, Departament of Animal Science. 76 p.

Fernández, F.; Ovalle, C. y Fraga, A. 1999. Adaptación de tagasaste (Chamaecytisus proliferus spp. palmensis) en el secano mediterráneo subhúmedo y húmedo. En: Soto, P. y Teuber, N. (Eds.) XXIV Reunión Anual Sociedad Chilena de Producción Animal (SOCHIPA) A.G. p. 25-26.

Fraga, A.; Cortes, K. y Ovalle, C. 1999. Distribución y descripción En: Ovalle, C; Fraga, A.; Fernández, F.; Avendaño, J. y Cortés, K. (Eds.) El tagasaste en Chile p. 15-18.

National Research Council. 1984. Nutrient requirements of beef cattle. 90 p.

Opazo, R. 1930. Agricultura. monografía cultural de las plantas agrícolas. Tomo III. Plantas forrajeras y Plantas Industriales p.156.

Ortega, F.; Méndez, P.; Fernández, M. y Santos, A. 1990. (Chamaecytisus proliferus (l.f.) link spp. palmensis (christ kunkel). Una leguminosa forrajera arbustiva originaria de la isla de la Palma. Revista Canarias Agrarias y Pesqueras 8:328-332.

Ovalle, C.; Aronson, J.; Longeri, L.; Herrera, A.; and Avendaño, J. 1996. Nitrogen fixation, nodulation and biomass accumulation in three Chilean legumes trees and tagasaste Chamaecytisus proliferus subsp. palmensis. Proceeding of the eleventh Australian Nitrogen Fixation Conference. Perth 22 - 27 september 1996 p.65-67.

Ovalle, C.; Aronson, J.; Alvarez, H.; Meneses, R. y Neira, L. 1993. Alfalfa arbórea o tagasaste (Chamaecytisus proliferus subsp. palmensis) un árbol forrajero leguminoso con potencial para sistema agrosilvopastorales en Chile mediterráneo. Agricultura Técnica 53 (3): 264 -271.

Snook, C. 1961. Tree lucerne a fodder crop with a future. Journal of agriculture of western Australia. 4th series. 2:173-179.

Nutritive value of fodder trees in the mountains of Northern Chiapas, Mexico

Jiménez-Ferrer, Guillermo[211], Ramírez-Avilés[212], Luis, Kú-Vera, Juan[213]
Soto-Pinto, Lorena[214], Villanueva-López, Gilberto[215]

Key words: degradability, Mayas, on-farm research, participatory research

Introduction

Cattle production in the tropical areas of Mexico is based primordially on extensive systems. The use of trees for fodder is a marginal practice in southeastern Mexico (Soto, 1990). Indigenous fodder trees play important cultural and economic roles. In the southeast of Mexico, the Indian farm producers have good potential for the development of sustainable systems of cattle production since there is a wide diversity of forage trees in their communities. In the Maya-Tzotzil region of northern Chiapas producers practice an agrosilvopastoral mountain system (AMS) in temperate zones (±2000 m above sealevel) that utilizes grassland forests and fallow land (acahuales). One of the main restrictions is the scarcity of fodder from November to march due to frost and the dry season. Considering the importance of designing robust agroforestry systems for cattle, the objective of this study was to evaluate the chemical composition and degradability of the foliage of the principal trees used for fodder in the AMS: Acacia angustissima, A. pennatula, Eysenhardtia adenostylis, Chromolaena lobuta and Saurauia scabrida.

Materials and methods

The present study was carried out during 1998 in Lázaro Cárdenas and Rincón Chamula, Mayan communities located in the mountains of northern Chiapas, Mexico. During the research was focus on participatory research in livestock (IIED, 1994) and on-farm research (Stroud, 1993).

Selection of woody species

The evaluated species were selected according to the criteria of the producers who indicated each of the species consumed regularly in AMS (Jiménez et al., 1997).

Animals

Four entire steers Cebú x Swiss from the community herds of L. Cárdenas, with a mean (± SD) live-weight of 300 ± 6.1 kg were surgically fitted in the rumen by means of Dugerthy’s technique (1955).

Selection of samples and chemical analysis of foliage

In Rincón Chamula, samples of foliage (leaves and petiole) of the five selected species were collected in the rainy season (July) as well as in the dry season (March). Dry matter (MS) and crude protein (PC) were evaluated according to AOAC (1980). Neutral detergent fiber (FDN) and acid detergent fiber (FDA) were determined according to Van Soest et al. (1991).

Degradability of dry matter and crude protein

A degradability trial was carried out in the community of L. Cardenas, Simojovel, Chiapas (September 1998). The steers were housed indoors in individual pens measuring 4 x 4 m. The steers were fed ad libitum a basal diet of Taiwan grass (Pennisetu. purpureum) cut and mixed with green foliage (leaves and petiole) of “Shanté” (Gliricidia sepium) in the ratio 75:25 for 14 days. The feed was given in the morning (06.00 h). Incubation times were 3, 6, 12, 24, 48, 72 and 96 h. The MS and PC degradability constant and effective degradability (ED) were estimated using the equations of Orskov and MacDonald (1979). The degradability data was analyzed using the NAWAY computer programme (RRI, 1995) and the program SAS General Linear Model Procedure (SAS, 1990). The differences between species and seasons were assessed by Student Range Test.

Results and discussion

Chemical composition of foliage

The chemical composition for the species are presented in Table 1. There is a large variation among species and between seasons. These results coincide with those reported by Joshi and Sing (1990) and Nahed et al. (1998).

Degradability of MS and PC

The mean rumen degradation constants for dry matter (DM) of the five fodder trees are given in Table 2. The potentially degradable fraction was higly significantly different (P <0.01) among species, but not between seasons. The highest average annual values were for C. lobuta (90.2 %), S. scabrida (76.7 %) and E. adenostylis (71.7 %). Lowest values were for A. angustissima (36.7 %) and A. pennatula (40.02 %). The rapidly degradable fraction for dry matter was significantly deifferent (P < 0.05) among species and between seasons, being the highest average for Acacia species. The slowly degradable fraction of MS was significantly different (P <0.05) between species. Highest values for both seasons were observed in C. lobuta (85.9 - 71.2 %) and S. scabrida (67.1 - 61.2 %). The degradation rate constant for MS was significantly different (P < 0.01) among species and between seasons, This parameter was high for A. angustissima (29 %/h), E. adenostylis (18 %/h) and C. lobuta (12 %/h), in comparison with A. pennatula (8 %/h) and S. scabrida (7 %/h). The effective degradation (DE) of MS was significantly different (P < 0.01) among species and was not significantly different (P > 0.05) for season. Average annual values were high for C. lobuta (79.7 %), intermediate for E. adenostylis (66.0 %) and S. scabrida (61.0 %), and lowest for A. angustissima (39.1 %) and A. pennatula (37.7 %).

A. angustissima and A. pennatula presented a slight reduction of DE when the rumen fractional outflow rate increased, while S. scabrida and E. adenostylis had a reduction of more than 25 %.

The rumen degradation constants for crude protein (PC) are given in table 3. All constants were significantly different (P< 0.01) due to season and species The potentially degradability fraction of PC showed an average range between both seasons ranging from 36.9 to 62.0 %. The degradation rates of PC was significantly different among species (P<0.01) and seasons (P< 0.05), being low for all species (2 %/h to 4 %/h). The effective degradation (ED) of PC were different (P<0.01) between species and seasons. Increasing rumen fractional outflow decreased ED.

Conclusions

Some species such as A. angustissima and A. pennatula show limitations characteristic of this genus (low degradability) for the nutrition of ruminants; however, this resource needs subsequent evaluation, since it is widely used as browsing material in AMS. C. lobuta, S. scabrida and E. adenostylis deserve special attention for their acceptable degradation levels of MS, making necessary subsequent toxicity studies of animal and agroforestry establishment. This research allowed a successful experience on farm-research with Mayan producers in the context of searching for agroforestry alternatives.

Bibliography

AOAC (1980) Official Methods of Analysis of the Association of Official Analytical Chemist, 15th Ed., Association of Official Analytical Chemist, Washington, DC, USA.

Dougherty, R.W (1955) Permanent stomach and intestinal fistulas in ruminants: Some modifications and simplifications. Cornell Veterinary 45 (3):331-357.

IIED (1994) Rapid Rural Appraisal. Special Issue on Livestock. International Institute for Environment and Development. RRA Notes No. 20. UKA 173 p.

Jiménez-Ferrer, J.G., De Jong, B., Soto, P.L., Montoya, G (1997) Aprovechamiento agroforestal sustentable y captura de carbono en la región norte del estado de Chiapas, México. El Colegio de la Fronteras Sur (ECOSUR), Chiapas, Mex. 102 p.

Jhosi, N.P., y Sing, S.B (1990) Availability and use of shrubs and tree fodder in Nepal. In: Devendra, C. (Ed.), Shrubs and Tree fodder for farm animals. Proceedings of a Workshop in Denpasar, Indonesia, IDRC, Ottawa, Canada, pp. 211-220.

Nahed, J., Sánchez, A., Grande, D., y Perez-Gil, F (1998) Evaluation of promissory tree species for sheep feeding in the Highlands of Chiapas, México. Animal Feed Science and Technology 73:59-69.

Orskov, E.R., y McDonald, I (1979) The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. Journal of Agricultural Science. Cambridge. 92:449-503.

RRI (1995) Software para calcular parámetros de degradación. Rowett Research Institute, Aberdeen, Great Britain. http://www.rri.sar.ac.uk

SAS (1990) SAS Institute Inc., SAS Campus Drive, Cary, NY, North Carolina, USA.

Soto-Pinto, M. L (1990) Plantas útiles de cuatro comunidades de Chiapas: perspectivas en el uso sostenible de la tierra. Revista Fitotecnia Mexicana 13:149-168.

Stroud, A (1993) Conducting On-Farm Experiments. Pub. No. 228, CIAT, Cali, Colombia, 118 p.

Van Soest, P.J., Robertson, J.B., y Lewis, B.A. (1991) Methods for dietary fiber, neutral detergent fiber, and no starch polysaccharides in relation to animal nutrition. Journal of Dairy Science 74:3583-3597.

Table 1 Chemical composition (g kg-1DM) of five fodder trees in dry season (D) and rain season (R) from agrosilvopastoral mountain system in north Chiapas, Mexico.

Specie

Season

DM

CP

NDF

ADF

Acacia angustissima

D

478

195

442

293

R

369

242

570

419

Acacia pennatula

D

531

110

495

423

R

419

205

412

345

Eysenhardtia adenostylis

D

328

190

433

250

R

301

158

614

402

Chromolaena lobuta

D

324

101

366

354

R

234

108

588

522

Saurauia scabrida

D

323

71

481

388

R

276

82

620

384

Table 2. Dry matter degradability (g/Kg) of five fodder trees in dry season (D) and rain season (R) from agrosilvopastoral mountain system in north Chiapas, Mexico.

Constants

Species

Significance



Aa

Ap

Ea

Cl

Ss

Species

Season

a (g Kg-1)

D

250

252

127

470

610

**

*

R

232

267

98

184

156



b (g Kg-1)

D

116

149

579

859

670

**

ns

R

162

171

627

712

612



a+b (g Kg-1)

D

367

402

707

907

732

**

ns

R

402

439

725

896

766



c (%/h)

D

0.37

0.07

0.20

0.16

0.09

**

**

R

0.21

0.08

0.17

0.09

0.05












ED2 (g Kg-1)

D

389

383

663

783

615

**

ns

R

391

370

657

810

605



ED5 (g Kg-1)

D

369

346

593

666

493

**

ns

R

378

340

588

697

482



ED8 (g Kg-1)

D

354

326

539

581

416

**

ns

R

373

323

535

615

407



Aa=Acacia angustissima, Ap= A. pennatula, Ea= Eysenhardtia adenostylis, Cl= Chromolaena lobuta, Ss= Saurauia scabrida.

a = rapidly degradable and soluble fraction; b = slowly degradable fraction; c = fractional rate constant of degradation (%/h); a+b = degradability potential fraction.

** = p < 0.01. * = p < 0.05

ED= Effective degradability to different outflow rate (2, 5 y 8 %/h).

Table 3. Crude protein degradability (g|Kg) of five fodder trees in dry season (D) and rain season (R) from agrosilvopastoral mountain system in north Chiapas, Mexico.

Constants

Species

Significance



Aa

Ap

Ea

Cl

Ss

Species

Season

a (g Kg-1)

D

103

164

160

1551

148

**

**

R

129

138

103

634

182



b (g Kg-1)

D

247

258

261

433

453

**

**

R

257

243

330

44

454



a+b (g Kg-1)

D

350

423

422

588

602

**

**

R

387

381

433

504

637



c (%/h)

D

0.03

0.03

0.02

0.02

0.01

**

**

R

0.03

0.04

0.02

0.06

0.07












ED2 (g Kg-1)

D

251

320

301

378

344

**

**

R

286

311

287

403

361



ED5 (g Kg-1)

D

196

261

243

284

254

**

**

R

228

259

214

316

277



ED8 (g Kg-1)

D

171

235

219

246

221

**

**

R

201

231

182

265

201



Milk production in a silvopastoral system under commercial conditions.

L. Lamela[216], Tania Sanchez[217], O. López[218], Saray Sánchez[219] & Magaly Díaz[220]

Key words: Leucaena, milk production, silvopastoral system

Introduction

The incorporation of ligneous species joined by twining legumes and improved grasses is a choice for Cuban livestock production because, under research conditions, milk productions have been obtained similar to those found when medium levels of fertilization are applied. Besides, a high persistence of legumes and grasses is maintained in the pastures (Hernandez, Carballo, Reyes y Mendoza 1998).

The objective of this work was to introduce a Silvopastoral System with Leucaena leucocephala in a livestock farm and to determine its productive results

Materials and methods

An area of 47 ha on a brown soil with carbonates was used in the 066 typical dairy of the Genetic Enterprise of Matanzas (GEM), from which 42 ha were dedicated to grazing and 5 ha to the production of sugar cane and king grass forage.

Animals

42 and 68 first lactation Mambi cows (75% Holstein * 25 % Zebu) were used during the first and second year of exploitation respectively, which had a live weight of 422 kg and the stocking rate was 1,3 and 1,6 cows/ha for the first and second year respectively.

The milking was carried out mechanically at 5:00 a.m. and 2:30 p.m. and during it a commercial concentrate was supplied ate a rate of 0.8 kg/cow/day in addition to mineral salt ad libitum.

Pastures

A work of improvement of the degraded pasture was performed by means of the rehabilitation of Cynodon nlemfuensis cv. Jamaicano and the substitution of natural pasture by the improved grass Panicum maximum cv. Likoni.

In order to achieve this, the turning up of the area was performed and then the chopper took a turn on it. Afterwards, L. leucocephala cv. Cunningham was sown with 5.6 m among furrows, and between rows C. nlemfuensis was rehabilitated or Panicum maximum was sown; the sowing stage of these species was developed from July to August 1996. In April 1997, the establishment of L. leucocephala was determined. To facilitate the management of the grazing area, this was divided into 37 paddocks of 1 ha each, in order to guarantee the needed resting time, which lasted 28 - 35 days in the rainy season and 42 - 66 days in the dry season (Guevara, 1999).

Dry matter availability was determined monthly before the entrance of the animals to the paddocks by means of the technique proposed by Martinez, Milera, Remi, Yepes y Hernandez (1990). Every two months, samples of the feed used were sent to the laboratory in order to determine CP, CF, Ca and P contents.

In the dry season, grazing time was restricted to 12 hours from 4:30 p.m. to 4:30 a.m. and sugar cane was supplied in the sheds during the early hour of day in order to satisfy dry matter needs, whose offer and residue were determined every month by weighing the fed.

Results

Pastures quality (table 1) showed a high content of protein in L. leucocephala, which is characteristic of this plant; and acceptable values of this indicator were found in the grasses, similar to those reported when fertilizers between 150-200 kgN/ha/year are used. The quality of king grass and sugar cane is within the established values without irrigation, where organic manure is applied after every cutting.

Table 1. Chemistry composition of feed

Feeds

DM

CP

CF

Ca

P

L. leucocephala

31.94

29.40

16.08

1.51

0.26

C. nlenfuensis

27.64

10.57

30.81

0.50

0.29

P. maximum

34.60

14.59

32.59

0.65

0.27

Sugar cane

26.2

2.57

30.39

0.45

0.04

King grass

16.0

7.42

16.93

1.46

0.10

Concentrate

86.1

15.80

5.92

0.62

0.43

The DM availability of grasses reached acceptable values in both seasons (fig. 1) if we take into account that no fertilizer was applied.

Fig. 1. Dry matter availability in the paddocks

During the evaluation of the association a stability of L. leucocephala population was found, with a low increase under commercial conditions of production (table 2) and with a good development of plant height and stem diameter showing a good adaptation to those soil and management conditions.

Table 2. Characterization of L. leucocephala in the pasture

Indicators

Periods

May 98

May 99

May 2000

Height (cm)

282

340

357

Diameter (cm)

2.1

3.5

3.6

Density (plants/ha)

10 491


10 585

During the utilization of the pasture the appearance of twining legumes was observed, from which glycine (Neonotonia wightii) was the main species and within the improved grasses C. nlemfuensis was predominant.

Table 3. Population of legumes and grasses(%).

Population

May 98

May 99

May 2000

Legumes

0

9.8

7.8

C. nlemfuensis

24

41.7

37.6

P. maximum

42

19.7

22

Weeds

7

2.8

8.5

Other grasses

27

26

24.1

The analysis of milk production showed that there was no effect of the calving two month-period, but the two-month period of production did have effect and there were significant differences among the seasons and years (fig. 2). The two-month period with higher milk production was July - August and the one with lower milk production was November - December, the rest kept intermediate values.

Fig. 2. Milk Production

Other indicators of milk production are shown in table 4, in which we appreciate that the lower milk production in the first year was determined by just placing the average 28 ha system of grazing under exploitation, due to delays in the enclosing of the unit, as it did not happen innthe second year, in which 42 ha were incorporated.

Table 4. Other indicators of milk production.

Year

L/ha of grazing/year

L/ha of system/year3

Milk production (l)

1

3 366(1)

2 005

94 268

2

3 865(2)

3 454

162 344

(1) Calculated for the 28 ha under exploitation.

(1) Calculated for the 42 ha under exploitation.

(2) Calculated for the 47 ha of the system

During the dry season (December to May) the animals consumed mainly sugar cane forage and sometimes king grass in the sheds.

Table 5. Feed intakes in the dry season.

Feed

Time

Kg DM/cow/day

Kg DM/cow/day

Grounded sugar cane

Diciembre - May

13.3

3.2

King grass

May

8.1

2.7

Conclusions

The resting times in the rainy season (28 - 35 days) and in the dry season (42 - 66 days) and the management with stocking rates between 1,3 and 1,6 cows/ha contributed to keeping the stability of the botanical composition.

The biodiverse system with grasses, creeping legumes and trees maintained an adequate chemistry composition and biomass availability for producing more than 7.5 l of milk/cow/day.

Individual milk production of the cows was higher in the first yeas than in the second one (8,8 vs. 7,9 l/day) but yield per area increase in the second year with the moderate increase of the stocking rate (3 366 vs. 3 865 l/ha/year).

References

Guevara, V. R. 1999. Contribución al estudio del pastoreo racional con bajos insumos en vaquerías comerciales. Tesis presentada en opción al grado de Doctor en Ciencias Veterinarias. Universidad Agraria de la Habana. p 18.

Hernandez, D. Carballo, Mirta; Reyes, F. & Mendoza, C 1998. Explotación de un Sistema Silvopastoril multiasociado para la producción de leche. III Taller Internacional Silvopastoril. Los árboles y arbustos en la ganadería. Estación Experimental de Pastos y Forrajes “Indio Hatuey. Matanzas. Cuba.

Martinez, J; Milera, Milagros; Remi, V; Yepes, I. & Hernández, J (1990).Un método ágil para estimar la disponibilidad de producción de leche. Pastos y Forrajes. Pastos y Forrajes 13:101.

Comparison of the in vitro gas production and nylon bag degradability of some fodder tree species

Henry Lizarraga S.[221], Francisco J. Solorio S.[222], Carlos A. Sandoval C.[223]

Key words: leaves, nutritive value, tropics, stem

Introduction

Fodder trees are well known in the tropics as food alternative to use in the dry season when there are a shortage of livestock feed. However, trees fodder need a more understanding which should comprise not only their fodder potential but also the digestibility of their nutrients which are very closely related to the energy requirements of ruminants. As a nutritive value index, digestibility provides a biologically meaningful parameter that can be used in a routine feed evaluation (Kitessa et al., 1999). The in vitro gas production and the nylon bag degradability are two useful techniques to the rapid screening of feeds to asses their potential as energy sources.

The present study has the objective of evaluate the rumen degradation of dry matter, CP, NDF and its relationship with the in vitro gas production from foliage of tree species: Brosimun alicastrum (ramon), Piscidia piscipula (jabin), Leucaena leucocephala (huaxim), Lisyloma latisiliquum tzalam),and Guazuma ulmifolia (guazuma).

Material and methods

The experiment was conducted at the Faculty of Veterinary Medicine and Animal Production, University of Yucatan located in the central region of the state of Yucatan, Mexico. Presents a climate Aw0, at an altitude of 8 m a.s.l., with annual rain fall and temperature of 980 mm and 26 oC, respectively.

In situ degradation

The tree foliage (divided into leaves and edible stem less than 6 mm in diameter) were incubated in three Bos Indicus, cattle (437.25 ±23.59 kg LW) receiving 70% fresh forage (Pennisetum purpureum) and 30% concentrates with 180 g CP/kgDM. To ensured the feed potential to be expressed under standardised conditions. Bags were incubated reverse order (96, 72, 48, 24, 12, 6 h), each point being measured by duplicates on each animal, in addition washout losses were measured by rinsing two bags with tap water.Data was fitted to the exponential equation y=a+b(1-exp(-ct))

In vitro gas production

Rumen samples were obtained from two of the steers used for the in situ measurements, and collection was in contemporary periods. It was collected at 08:00 h, before the morning feeding, placed into container sealed immediately and transported to the laboratory (100 m away), the preparation of N-rich medium was as described by Menke and Steingass (1988). The method used for the gas production measurements was as described by Theodorou et al., (1994). Gas production was determined up to 120 h utilising four 125 ml capacity serum bottles with 1.0g DM/sample. DM loss was calculated as the difference between the initial and final DM weight of the sample. In vitro cumulative gas production, was fitted to the exponential equation y=a+b(1-exp(-ct)). The PF was determined for 120 h of incubation (ml gas/gDM fermented) as suggested by Blummel et al., (1994).

Statistical analysis

Both, fitted values of gas production and the partitioning factor were employed to estimate the effective fermentation at time intervals equal to those employed for the in situ incubation as follow: sample fermented = (CGP at any given time)/(PF). The relationship between predicted and actual in situ measurement was assessed by linear regression analyses. It was also assumed that in situ would yield higher results than those estimated from in vitro data due to the washout losses (Wo). In situ material is exposed to the probability of escaping without being fermented while in vitro sample will always remain in the bottle. Thus Wo were used to recalculate the in situ data. In order to do that, the disappearances were calculated against 1-Wo. The relationship resulting after this adjustment was also assessed by mean of linear regression analyses.

Results

Gas production and rumen degradability

In presenting the results, in the portion leaves and stem the ramon, guazuma and huaxim show significant differences (P<0.05) among the five species. The highest value were ramon, guazuma and huaxim, and the lowest for tzalam (Table 1). The stem portion, tzalam show the lowest value (163 mlgas/g DM), while the other four tree species ranked similar values (215 to 244 mlgas/g DM).

Mean in situ degradation value (89-65 % OM) differed (P<0.05) between species. The potential degradation (a+b) of the CP show similar value for ramon, jabin, guazuma and huaxim with values ranged from 95 to 88%. On the other hand is important to highlighting that in none of the two cases the tzalam adjusts to the degradation equation curve (Table 2).

Correlation among the in situ test degradation and the in vitro gas production.

All the relationships show that the quadratic regression is significant (P <0.001), with R2 values ranged from 0.97 to 1.0 for both portions (leaf and stem) (Table 4).Huaxim and jabin produced small amount of gas compared to the high in situ degradation observed. Probably due to antinutritional factors such mimosine and tannins.

Discussion

Relationship between in situ degradation and in vitro gas production techniques

All the species show high in situ degradation, it could be a good nutritive value index to considered the assessment of other trees. The relative ranking of two tree fraction was similar when evaluated by in situ degradation and in vitro gas production. Correlation between the ranking given by the both techniques indicated the strong relationship between them. The gas production liberated when the foods are incubated in vitro with ruminal liquid are related with the degradability and therefore with the energy value of the food (Menke and Steingass, 1988). However, more study is required in order to identify possibly interactions between the fodder material and the methodology utilised.

Table 1. Fitter parameter for In vitro gas production (ml/g DM) of five fodder trees.

Specie

a

b

c

Total gas production

SED

Leaf






B. alicastrum

-16.6 a

232.0a

0.018 a

250.81 a

5.08

P. piscipula

-5.53 b

127.4d

0.016 a

209.97 b

2.74

L. leucocephala

-9.75 bc

160.2c

0.014 ab

208.30 ab

3.07

L. latisiliquum

-5.51 b

92.8 e

0.010 b

155.60 c

5.70

G. ulmifolia

-11.5 c

192.8b

0.012 b

245.04 a

4.00

S.E.

2.07

24.3

0.001

16.9


Stem






B. alicastrum

-11.9 a

138.2 a

0.021 a

244.28 a

3.66

P. piscipula

-8.49 ab

129.1 a

0.013 b

225.59 a

2.42

L. leucocephala

-6.01 b

85.98 c

0.020 a

218.10 a

2.58

L. latisiliquum

-3.69 b

41.86 d

0.010 b

162.72 b

1.66

G. ulmifolia

-8.09 ab

106.9 b

0.011 b

215.23 a

3.76

S.E.

1.36

17.2

0.002

13.5


Different subcripts within rows indicate significant differences (P<0.05)
SED = Standart error deviation

Table 2. Shows the potential degradation (a+b) of the leaves and stem. The rumen degradation for leaves ranked from 64 to 89% for tzalam and ramon respectively and from 49 to 58% for stems portion. It is evident that tzalam had a very low potential degradation.

Table 2. In situ degradation (% DM) of leaves and stem from five tree species.

Specie

a

b

C

Lag

Wo

SED

Leaf







B. alicastrum

28.5 a

60.72a

0.082a

2.29

39

2.96

P. piscipula

40.35b

25.20b

0.036b

0.27

41

3.31

L. leucocephala

40.20b

35.62c

0.054c

0.25

41

2.55

L. latisiliquum

36.33c

28.37b

0.024d

2.73

38

2.29

G. ulmifolia

29.25a

49.11d

0.055c

0.09

29

2.88

Stem







B. alicastrum

16.21a

42.16 a

0.11a

2.40

26

5.75

P. piscipula

19.87a

38.65 a

0.092ab

2.80

28

4.75

L. leucocephala

15.29a

33.19a

0.13ac

2.96

26

3.97

L. latisiliquum

24.90b

24.37 b

0.06d

0.76

26

2.81

G. ulmifolia

21.62a

28.16 a

0.049e

1.17

23

3.58

Different subcripts within rows indicate significant differences (P<0.05)
Lag = Phase Wo = Washout loss
SED = Standart error deviation

Table 3. In situ OM and CP degradation from leaves of five tree species.

Specie

A

b

c

SED

OM





B. alicastrum

28.29b

60.75a

0.08a

2.95

P. piscipula

37.13a

28.33d

0.03c

3.45

L. leucocephala

38.29a

36.97c

0.05b

2.68

L. latisiliquum

N.A

N.A

N.A

N.D

G. ulmifolia

28.43b

48.72b

0.05b

2.94

CP





B. alicastrum

39.01a

55.27a

0.07a

1.48

P. piscipula

45.96a

49.44a

0.007a

1.32

L. leucocephala

56.89b

31.66a

0.04a

2.89

L. latisiliquum

N.A

N.A

N.A

N.D

G. ulmifolia

42.42a

50.88a

0.03a

2.26

Different subscripts within rows indicate significant differences (P<0.05)
N.A =don't adjust to the equation p = a+b(1-exp-ct)
SED = Standart error deviation

Table 4. Relationship between observed (Y) In situ degradation and predicted (X) values from in vitro gas production.

Specie


R2

Leaf



B. alicastrum

Y= -0.0287X2+2.88X+13.41

0.988

P. piscipula

Y= -0.0202X2+1.71X+ 4.41

1.000

L. leucocephala

Y= -0.0282X2+2.29X+12.81

0.996

L. latisiliquum

Y= -0.0209X2+1.77X+ 3.20

1.000

G. ulmifolia

Y= -0.0322X2+2.61X+16.44

0.995

Stem



B. alicastrum

Y= -0.0359X2+2.31X+ 9.39

0.975

P. piscipula

Y= -0.0432X2+2.52X+ 8.26

0.970

L. leucocephala

Y= -0.0505X2+2.40X+ 4.87

0.953

L. latisiliquum

Y= -0.0776X2+2.53X+11.77

0.986

G. ulmifolia

Y= -0.0434X2+2.12X+ 8.46

0.996

All species -leaves-

Y= -0.0254X2+1.77X+ 9.51

0.88

All species -stem-

Y= -0.0078X2+1.56X+11.00

0.81

Conclusions

The two techniques assessed in this work can be used to determine the DM fermentation of tree fodder portions. Both techniques provide similar ranking of fodder trees value. However, is important to consider the time and availability of materials (fistulated animals, laboratory equipment etc.) when choosing the technique.

References

Blümmel, M., Steingass, H. and Becker, K. (1994). The partitioning of in vitro fermentation products and its bearing for the prediction of voluntary feed intake. Proceeding of the Society for nutrition and physiology. 3: 123.

Kitessa, S., Flinn, P.C., and Irish, G.G. (1999) Comparison of methods used to predict the in vivo digestibility of feeds in ruminants. Aust. J. Agric. Res. 50: 825-841.

Menke, K. H and Steingass, H. (1988). Estimation of the energetic feed value obtained from chemical analysis and in vitro gas production using rumen fluid. Animal Research and Development 28: 7-55

Orskov, E, R., Hovell F. D. D. and Mould F. (1980). The use of nylon bag technique for the evaluation of feedstuffs, Trop. Anim. Prod. 5: 195-213.

Theodorou, M. K., Williams, B. A., Dhanoa, M. S., Mcallan, A. B. and France, J., (1994). A simple gas production method using a pressure transducer to determine the fermentation kinetics of ruminant feeds. Anim, Feed Sci. Technol., 48: 185-197.

Fodder production and chemical composition of five tropical forage tree species under natural conditions

Henry Lizarraga S.[224], Francisco J. Solorio S.[225], Carlos A. Sandoval C.[226]

Key words: foliage, nutrient content, tannin, tree growth

Introduction

At Latin American level it is well-known the important role that fodder trees play as an alternative to feed farm animal during the dry season or shortage time. In these areas are generally, small farm growth trees to use them as cut and carry systems. Tropical trees and shrubs posses important characteristic in comparison to others plants. Important characteristics of trees are: high biomass production, resistance to the dry period, tolerance to the salinity and adaptation to different soil types, as well as their nutritious value (Nefzaoui, 1997). In spite of the fact that the list of trees and bushes with potential use as forage comprise more than 300 species, the emphasis has been given to very few. Given the diversity of trees, an urgent necessity exists to study and to recommend promising species for specific ecological-agriculture environments and cattle production systems.

The objectives of the present study is to determining the productive and chemical potential of tree fodder species in addition to the dry matter degradation of: ramon (Brosimun alicastrum), jabin (Piscidia piscipula), huaxim (Leucaena leucocephala), tzalam (Lisyloma latisiliquum) and guazuma (Guazuma ulmifolia).

Materials and methods

The study was carried out in the Department of Animal Nutrition of the Autonomous University of Yucatan, Mexico, during the months of August of 1999 to April of 2000. The experimental area presents a climate Aw0, at an altitude of 6 m a.s.l., with yearly precipitation of 953 mm., and annual average temperature of 26°C.

Foliage production

The foliage production was evaluated in 60 trees (12 for specie) of 5 arboreal species: ramón (B. alicastrum), guazuma (G. ulmifolia), huaxim (L. leucocephala), jabin (P. piscipula) and tzalam (L. latisiliquum), in the months of August to October of 1999. The method used to determine the quantity of biomass (kg/MS/árbol) was an adaptation of the technique of double sampling, carried out in tropical forest by Bonham, (1989). The trees were divided into three groups:

Group 1 (N = 4) trees of 4 - 6 m. of height.
Group 2 (N = 4) trees of 6 - 8 m. of height.
Group 3 (N = 4). trees> of 8 m.

A sub sample was carried out to determine the stem-leaf relationship, separating leaves + edible stems (diameter less of 5mm in diameter) and woody stem.

Statistical analysis

With the biomass data (comprising biomass and basal area) were carried out regression analysis. The data were procesed using the General Linear Model of GENSTAT. 3.2.

Chemical analysis and in situ dry matter degradation at 96 h. time

Tree leaf and stem samples of each tree species were carried out the chemical analyses of DM, OM, CP according to AOAC (1980); NDF, ADF and lignin as Van Soest (1963), total phenols and tannins according to Martin and Price, (1977). In addition, the samples (leaves and stems), were incubated during 96 hours time in the rumen of three heifers cross Bos Indicus X Bos taurus fed with taiwan (Pennisetum purpureum) grass and a concentrate with 18 % protein in the proportions of 70:30%, respectively.

Results

Fodder production

The fodder production of trees, is show in the Table 1. Trees of 6 to 8 m height had more edible biomass. The ramon had 56 kgDM/tree followed by guazuma and tzalam with 29 and 28 kgDM respectively, while the trees lopped at 4 to 6 m show relatively low DM production.

Table 1. Fodder production (kgDM/tree) in tree species lopped at different height.

Specie

Height (m)

4-6

6-8

> 8

Fodder

Stem

Fodder

Stem

Fodder

Stem

B. alicastrum

2.69

1.37

41.8

19.8

55.9

25.9

P. piscipula

3.52

1.86

6.3

4.8

13.0

9.9

L. leucocephala

N.D

N.D

6.3

2.9

11.3

6.4

L.latisiliquum

N.D

N.D

11.7

6.7

28.0

16.0

G. ulmifolia

4.07

3.98

7.47

7.3

29.0

28.4

ND = non determined.

The leaf-stem relationship is an indicator to estimate the quantity and quality of edible biomass. Table 2. show that, tzalam had high relationship followed by ramon (1.9 and 1.7) respectively; while that jabin and guazuma had low values. Although there were no statistical differences, large variation was found within tree species. Relating basal area and fodder production, the value of R2 was significant (P <0.05), for all the species. The ramon show the better relationship with R2 = 0.8, while jabin had the lowest R2 value (0.4).

Table 2. Leaf-stem relationship, basal area and fodder produccion correlation (R2).

Specie

Leaf (%)

Stem (%)

Leaf-Stem relationship

V.C (%)

R2

B. alicastrum

63.50

36.49

1.74

16.87

0.79

P. piscipula

57.14

42.85

1.33

28.11

0.44

L. leucocephala

61.17

38.82

1.57

28.22

0.57

L. latisiliquum

65.30

34.69

1.88

22.52

0.71

G. ulmifolia

57.76

42.23

1.36

11.72

ND

E.E

1.58

1.58

0.10

3.21


V.C. = variation coefficient

Chemical composition and in situ degradation

The chemical composition of trees is show in Table 3.2. It can be observed that the CP had a relatively high value which ranged between 15.5 to 29. The total phenols content of guazuma was low (1.4%) in comparison to tzalam (3.7%). In fibre contents, the ramon had the lowest FDN content (36%), value below the average of the other species; with 12.09% less than jabín. There were statistical differences (P <0.01) in the degradation at 96 h time in leaves among the five species used in this study (Table 3). The highest degradation values were for ramon (89%), guazuma (79%) and huaxim (77%). There were no significant differences (P>0.05) in stem degradation of ramón, jabin and huaxim.

Table 3. Chemical composition (%) and dry matter (DM) degradation of five fodder trees.

Specie/

DM

CP

NDF

ADF

Ash

TP

Tan

Lig

DMD

In situ D. 96 h

Leaf











B. alicastrum

41.8

16.9

36.0

28.8

11.6

1.7

0.74

6.8

69.5

89a

P. piscipula

38.5

18.5

48.1

28.9

12.6

1.8

0.74

14.8

47.9

64c

L. leucocephala

34.9

26.7

39.5

23.9

7.9

2.4

1.23

10.8

53.6

77b

L.latisiliquum

47.1

21.3

41.8

21.2

7.9

3.7

1.16

11.6

37.3

63c

G. ulmifolia

32.4

15.5

42.6

25.9

10.9

1.4

1.81

10.7

53.5

79b

Stem











B. alicastrum

44.5

10.3

67.5

47.1

7.4

0.2

0.27

N.D

47.9

59a

P. piscipula

39.2

9.5

67.4

45.9

9.8

0.8

0.33

N.D

44.9

60a

L. leucocephala

33.3

8.1

72.8

55.0

6.8

0.7

1.18

N.D

36.5

51a

L.latisiliquum

50.8

8.8

67.3

52.7

7.2

3.2

7.3

N.D

24.0

49b

G. ulmifolia

43.5

5.2

71.6

54.1

8.2

1.5

3.52

N.D

32.4

50b

DM= dry matter CP= crude protein NDF= neutral detergent fibre, ADF= acid detergent fibre, TP = Total phenols, CT = Condensed Tannin, Lig= Lignin, IDMD = in vitro dry matter digestibility, N.D = Non determined

Discussion

Fodder production and leaf-stem relationship

Analysing the results it should be said that a high DM production was obtained at 8 m or more ranging from 11 to 56 kg/tree/lopped. Although, the study of tree fodder has advanced in recent years, not enough is known about the potential of trees for supply of animal food during shortage times. However, this preliminary study shows the potential for coppice management of these tropical species. The importance of the leaf-stem relationship in the characterisation of fodder species allows to be considered the purpose of the final product mainly to satisfy some immediate needs, such as firewood or forage supplies, which should include the selection of trees with high leaf-stem correlation. Young stems show intermediary levels of CP ranged from 5 to 10 % high degradation values (50 to 60%), which mean that could be used in companion with tree leaves as supplements to low quality grass. However, is important analyse these forage supplies considering the animal consumption.

In general all the species had leaves with high protein content and intermediary to low values of phenol compounds. This mean that large amounts of this fodder could be used as supplement.

Conclusions

In general, the experiment demonstrate the importance of analysing the different components in a fodder production systems for use in the animal feeding. With simple way of measured, like tree growth (height and diameter at breast height), is possible predict the tree biomass. Although, it is recommendable to use local available data on tree growth to avoid erroneous comparison among sites and to ensure consistency. In the course of the work it was observed that, in most of the tree species when they were lopped at the end of the rainy season, showed an acceptable ability to produce sprouts with enough foliage during the drought, which mean one possibility to use these species as fodder reserves.

References

AOAC. (1980) Association of Official Analytical Chemists. Official methods of analysis. 13th Edition, Washington, D:C:

Bonham, C.D. (1989) Measurements for Terrestrial Vegetation. A John Wiley Intercience Publication.

Nefzaoui, A. (1997) The integration of fodder shrubs and cactus in the feeding of small ruminants in the arid zones of North Africa. Second FAO Electronic Conference on Tropical Livestock Feeds.

Van Soest, P.J. (1963) Use of detergents in the analysis of fibrous feeds. Journals of the Association of Official Agricultural Chemists 46: 829-35

Trees forage production and quality analysis with forage potentiality on a quarry soil in Merida, Yucatán, Mexico

E. Llamas[227], J. B. Castillo[228], C.Sandoval[229], F. Bautista[230]

Key words: arboreal species, agronomics, chemical composition, quarry.

Introduction

The tropical and subtropical zones contain the biggest diversity of vegetable species which have enough multifunctional purposes on one hand alone, which translate into an increase of animal productivity, then into human supplies for a growing community. Nevertheless, in spite of such richness, there is a constant deterioration of these ecosystems, this is due to deforestation, such process have caused loses in tropical countries in figures which represent the 17 million hectares per year (Ibrahim, et al, 1999), to name a few, changes in soil explotation for agricultural or stockbreeding means and feeding models, on the other hand, in some tropical regions, the stone explotation for the construction business, also causes deterioration of such natural resources, this mainly for the quarries. One of the available choices for improving animal food nourishment and restoration of deteriorated areas is the development of agricultural practices which promote integration between trees, bushes and animal production presenting itself as a valuable choice for the development of stockbreeding production systems (Szott, et al 1999; Jiménez, et al 1994).

The main purpouse for the developmetn of this job was to grade the forage production, the portions of leafs and stalks, and the chemical composition of the huaxín (L. leucocephala), algarrobo (A. Lebeeck), sacyab (G. sepium) and pixoy (G. ulmifolia), under the conditions of the quarry soil in Mérida, Yucatán, and eventually select new potencial solutions that could be introduced to the tropic or as components due to their sturcture and functionality, for the restauration of tired soils.

Materials and methods

Location, weather and soil

The universe for our study is located inside the grounds of an enterprise called “Materiales Anillos periférico, S.A.”, south from the Merida city of mexican state of Yucatán, at the following coordinates parallel (21º 51' N and 89º 41' S). The weather is Awo' (i)g, warm and subhumid, the average temperature is 26º C and rain records a 984.4 mm a year, with an even distribution between June and November (Duch, 1988). The soil is of calcarean nature with an influence of litosoles and rendzines.

Experimental Design and Statistical Analysis. For the variables, dry matter production and chemical composition, a randomly block-divided parcels was used as an experimental design with four repetitions, where it took the name of “big parcel” or crop, the species and era were considered as a subparcel or subcrop. For the production variables which showed relationship with the leaf-stalk and forage quality, the results were submitted to a variance analysis using an Statistical Análysis System (SAS 1985). Least significant (LSD) Dunacan's Multiple Range tests were used to determine statistical differences between treatment means.

Procedure

In the beginning, an homogenization cut took place at a meter from the ground, after the plants were manually prunned every three months, always recording the forage weight for each tree. The calculations for the dry matter production, were made by estimates of the values obtained when the dry matter was weighed and put through as a representative sample of 400 to 700 g having previously extracted manually the finer fractions (leaves and stalks under 5mm), those which were set in a dryer at a 70°C temeperature for 48 h at a constant weight. The grinded samples of leaves and stalks separatedly were used for the chemical analysis according the following techniques: raw protein by the method of Kjeldahl, neutral and acid detergent fiber, lignine and ashes (Quijano et al, 1996) and phenols, by the reduction of the ferric ion into a ferric state by ferropotasiumcyaniade (Price y Buther, 1977). All the samples were double checked in the animals nutrition lab of the mexican school of veterinary medicine and studies inside Yucatán's University.

Measures

For the total amount of forage's dry matter produced, the measuring period took place between June 1996 and ended on March 1998, this allowed us six dates which standed as milestones for our experiment which lasted two years. The chemical composition was analyzed along September 1997 and March 1998, because this time the largest and smallest forage production were introduced.

Results

Forage production

The Gliricidia sepium and Guazuma ulmifolia produced similar forage quantities (P<0.0001) showing superiority over Leucaena leucocephala and Albizia lebeeck along the first year, meanwhile during the second year, the Guazuma ulmifolia and Gliricidia sepium again produced the highest DM forage values (Table 1). Around september and december the yields introduced higher values for forage in comparison with March of both years (Table 1), thus interaction of the species by era showed differences (P<0.0001) for both years. The Leucaena leucocephala and Albizia lebeeck were distinguished in biomass production in a dry era, and accomplished a higher biomass relation with the season where the forage is acumulated. The production variation of these species and seasons were taken through out the years, as it was expected it turned out to be associated with rain fall (Figure 1).

Table 1. Forage Acumulated Production of four species of trees in a quarry at North Yucatán, México.


kg DM Tree-1

kg DM Ha-1

Species

(1996-1997)

(1997-1998)

Avg/Year

Gliricidia sepium

0.54 a

1.02 a

975.00 a

Guazuma ulmifolia

0.43 a b

1.16 a

993.75 a

Leucaena leucocephala

0.35 b

0.70 b

656.25 b

Albizia lebeeck

0.17 c

0.23 c

500.00 c

SE

0.07

0.09

0.07

Seasons




September.

0.60 a

1.03 b

1,018.75 b

December

0.34 b

1.09 b

893.75 b

March

0.14 c

0.14 c

175.00 c

SE

0.06

0.08

0.07

The averages with the same literal expression in a column are not statistically different at P< 0.05 (Duncan,1955), SE= standard error, 1250 plants/ha.

Leaf percentage according with stalk

The forage of trees, introduced differences (P<0.0001) in the leaf fraction for the effects on species and eras, in each case (Table 2). The Gliricidia sepium and Albizia lebeeck forage attained a larger proportion of leaves, which were similar yet different with the Guazuma ulmifolia and the Leucaena leucocephala which attained much lower values along both years. During March we recorded the highest proportion of leaves, oppositte to the months of September and December which presented themselves alike. During the second year a similar trend was recorded for the leaves fraction.

Table 2. Leave percentage of four different forage trees on a quarry soil at north Yucatán in México.


Leaf Proportion (%)

Species

(1996-1997)

(1997-1998)

Gliricidia sepium

73.05

74.65 a

Albizia lebeeck

67.84 a

62.42 b

Guazuma ulmifolia

60.22 b

55.42 b

Leucaena leucocephala

51.65 c

58.02 b

SE

2.79

3.08

Season



March

73.44 a

69.65 a

December.

56.92 b

61.56 b

September.

56.51 b

53.15 c

SE

2.49

2.75

Averages with same literal expression are not significatively different at P<0.05 (Duncan, 1955).

Forage chemical composition

Differences came up (P<0.0001) in the raw protein contents on leaves which recorded high values for the Leucaena (Table 3).For the contents pertaining to Neutral and Acid Detergent Fiber and lignine differences were shown (P<0.01) for both leaf and stalk of the species and era Ashes were a bit higher than the stalk. The highest values for Phenols were found in the leaves of the Guazuma ulmifolia and the Leucaena leucocephala with much less concentrations on the stalk. The effect on eras showed differences (P<0.05), along March the raw protein contents were higher than the ones recorded in September (Table 4). The stalk did not show differences between eras for the raw protein. The values for Neutral and Acid Detergent Fiber by leaf were over expectations in March in comparison with September this behaviour was similar also for the stalk, but in larger concentrations than the leaf, the leaf showed higher levels of ashes for the effect on the era meanwhile the stalk values for ashes turned out low. The contents of phenols for species and eras, showed on the leaf and stalk higher values in September than in March.

Table 3. Leaf and stalk chemical composition of four arboreal species on a quarry soil at Yucatán's north in Mexico.

Species

RP(%)

NDF(%)

ADF(%)

LIG(%)

ASH(%)

PHN(%)

Leaf







Leucaena leucocephala

22.07a

44.95b

24.57b

12.32b

10.39b

0.87b

Albizia lebeeck

21.64a

51.98a

31.55a

10.70b

8.72c

0.32c

Gliricidia sepium

19.82b

44.28b

30.28ac

16.42a

11.15a

0.27c

Guazuma ulmifolia

14.17c

44.05b

27.53bc

12.20b

10.36b

1.10a

SE

0.25

1.31

1.08

0.68

0.16

0.02

Stalk







Leucaena leucocephala

7.33a

80.32a

60.24a

20.60a

4.10c

0.26b

Albizia lebeeck

7.84a

78.92ac

55.95b

16.62bc

4.54.c

0.30b

Gliricidia sepium

8.08a

77.31bc

53.79.b

19.29a

6.13a

0.16c

Guazuma ulmifolia

4.37b

76.13b

56.43b

17.69ac

5.27b

0.77a

SE

0.26

0.74

0.91

1.03

0.13

0.05

Averages with same literal expresión are not significatively different P<0.05 RP= raw protein, NFD=Neutral detergent fiber, AFD= acid detergent fiber, LIG= lignine ASH= ashes, PHN= Phenols, ES= Standard error

Table 4. Seasonal influence in chemical composition of leaf and stalk of four arboreal species on a quarry soil at Yucatan's north in México.

Species

RP(%)

NDF(%)

ADF(%)

LIG(%)

ASH(%)

PHN(%)

Leaf







March

19.97 a

52.20 a

29.59 a

13.66 a

9.86 b

0.47 b

September

18.82 b

40.68 b

27.57 b

11.69 b

10.29 a

0.87 a

SE

0.17

0.89

0.74

0.46

0.11

0.02

Stalk







March

6.98 a

78.40 a

54.73 b

19.75 a

5.17 a

0.28 b

September

6.68 a

78.05 a

59.22 a

17.24 b

4.70 b

0.49 a

SE







Averages with same literal expresión are not significatively different at P<0.05 (Duncan, 1955).

Discussion

The variation attained from the forage production between the graded species during both years, is due to genetic morphological and ambiental differences customized for each species(Grime, 1989 Minson and Macleod, 1970). As being reported during the second year, the yield increased for all the species mainly the Gliricidia sepium and the Guazuma ulmifolia, this pointed out that such species had large availability to acumulate carbohidrates reserves between their tissues making the achieveing faster recovery in sprouts. Going along as planned the species object of our study produced yields according to the rain fall distribution pattern along the two years the experiment lasted. The difference between leaf proportion and species, might be explained as a slow growing process this avoided a quicker ripening of the plant and consecuently a quicker growth of the stalk, this accomplished a much better quality forage (Deinum, 1983). The raw protein contents in the leaf was higher and lower in the stalk, this might be explained that during the early vegetative process a larger amount of raw protein is present and it grows older as the growing continues and the plant ripens, increasing the dry matter at the stalk substracting then the contents of raw protein (Van Soest, 1982). The largest raw protein concetration introduced itself during March, it is attributed to this that the soil's humidity was reduced and the plants slowed their growing process and the dry matter qunatity produced by the leaf increased less a age came (Paterson 1933). Drawing conclusions, the species that produced tha highest biomass quantity were the Gliricidia sepium and the Guazuma ulmifolia although the dry era slowed the yields, showing the capability to keepp their production and quality all through the evaluation period. The nutricional value analysis pointed out that in spite of the variations between species and eras where a light impact took place, contrary to the behaivour of forage graminea, this makes evident the importance of having choices for nutricional suplements for ruminants and as being key components of animal production systems. On the other hand these species reported a satisfactory behaviour at recovering areas which presented degradation such as quarry which are common inside and outside Merida city in Yucatán.

References

Duncan, D.B. 1955. Multiple range and multiple F tests. Biometrics 11:1

Duch, G. J. 1988. La conformación territorial del estado de Yucatán. Componentes del medio físico. Universidad Autónoma de Chapingo. Centro Regional de la Península de Yucatán, Mex.

Deinum, B. 1983. Chemical Composition and nutritive value of herbage in relation to climate, proceeding of the 10th Meeting of the European Grassland Federation, Norway, 338-350.

Grime, J. P. 1989. Estrategias de adaptación de las plantas y procesos que controlan la vegetación. Ed. Limusa. México, D.F.

Jiménez, F, J., Nahed, T. J y Pinto, S. M. 1994. Sistemas silvopastoriles; una opción racional para la producción de leche en el trópico. XIII Reunión Técnica Científica del Sector Agropecuario y Forestal del Estado de Chiapas.,Tuxtla, Gutiérrez, México.

Minson, D.J and M. N. Mcleod, 1970.The digestibilility of temperature and tropical grass. Proc.11th Int. Grssland Congr. 719-722.

Patterson, D. 1933. Influence of time cuting on growth, Yield and Composition of Tropical fodder grasses. I. Elephant gras (Pannisetum purpureum). J. Agric. Sci. 23:615-641.

Price, L.M y Butler, G.L. 1977. Rapid visual estimation and spectrophotometric determination of tannin concents of sorghum grain. Journal of Agriculture and food Chemistry. Vol. 25: 1268-1273.

Quijano, R.C; Rosado, R y Gutierrez, S.B. 1996. Manual de análisis de alimentos. Laboratorio de Nutrición. FMVZ-UADY. Mérida, Yucatán. México.

SAS. 1985. SAS/STAT guide dor personal computers. Version 6 Ed. Carv. NC: SAS Intitute, Inc.

Szott, L.; Ibrahím, M. y Beer, J. 1999. The Hamburger connection hangover: cattle, pasture land degradation and alternative land use in Central America. CATIE. Costa Rica (en edición).

Van Soest, P.J. 1982. Nutritional Ecology of the Ruminant. Corvallis, Oregon E.U. Inc. Pp 374.

Grazing, browsing time and milk production of lucerna cows in a silvopastoral system in different seasons of the year

Liliana Mahecha L.[231], Mauricio Rosales[232], Carlos H. Molina[233]

Key words: animal behaviour, browsing time, Cynodon plectostachyus, grazing, Leucaena leucocephala, lucerna breed, Prosopis juliflora

Introduction

In general, little importance is given to the animal’s preferences while grazing. In silvopastoral systems the animal’s preference is of major importance because the availability of a variety of forages. Given the seasonal variation of the quantity and quality of the offered forages, it is necessary to adjust the supplementation accordingly, specially with highly productive animals. Silvopastoral systems with a high arboreal density offer a high quantities of protein, therefore imbalances of the protein:energy ratio can occur. A study was conducted in order to evaluate the grazing:browsing ratio with and without energy supplementation, milk production and their variation across the year, in a silvopastoral system of Cynodon plectostachyus, Leucaena leucocephala and Prosopis juliflora in the Cauca Valley, Colombia.

Materials and methods

This research was carried out in the Hatico Natural Reserve - farm located at 1000 m above sea level, in Cerrito, Cauca Valley (Colombia). The silvopastoral system consisted of C.plectostachyus, L. leucocephala and P. juliflora, divided into 42 plots of 4000 m2 each one. Four plots were randomly selected for this study. The system was conformed by three stratums. In the third stratum were P.juliflora trees (10 trees/ha). In the second stratum was L. leucocephala shrubs with a distance of 1 meter among furrows and 0.5 meter among plants inside the furrow. In the first stratum was C.plectostachyus grass, located in two places: under P. juliflora tree shade and outside it (between the furrows of Leucaena shrubs). Leucaena shrubs were pruned twice during the evaluation at the beginning of dry periods according to the traditional management of the farm. On average 68 Lucerna cows from the group of high production remained on one plot for one day and rotated, coming back to the same plot after 42 days. They remained in a plot of 4.000 m2 from 8:00 a.m. until 4:30 p.m. and continued from 6:30 p.m. until 5:00 a.m. of the following morning. During the afternoon milking period each animal received 2 k of rice bran and 1.5 k of chicken manure. The evaluation was conducted in two semesters of the year. In each semester three seasons were evaluated: dry season, moderate rainy season and wet season. Supplementation with molasses was only included in the second semester of the year.

Animal behaviour was monitored during day and night by direct observations on two cows selected from the evaluation group (one for each observer). Time spent in finding and eating P. juliflora pods, grazing time under and outside the trees; and browsing time were evaluated. Diurnal and nocturnal observations were made on alternate days of the same week for each season. Diurnal observations were carried out from 5 a.m. until 4:30 p.m. and nocturnal observations from 4:30 p.m. until 5 a.m. of the following morning. Animal behaviour was observed during intervals of five to ten minutes according to the method described by Márquez et al. (1983). The maximum possible distance was maintained in order to not affect normal animal behaviour. Behaviour variables were evaluated by completely randomised blocks model where one factor was the season of the year and the other was the time when activities were carried out (day or night). Means were compared by Duncan's test (Steel and Torrie, 1980) The effect of molasses on grazing and browsing time was evaluated through planned comparisons. Correlation and regression analysis were carried out to evaluate the relationship between grass and legume availability and digestibility with grazing and browsing time.

Voluntary forage intake (Leucaena and grass) was estimated by the agronomic method of Giraldo (1996) as the difference between forage availability before and after each grazing period divided by the number of animals grazing on each plot. A split plot strips statistical design was used to analyse the effect of the periods of the year (main strips) and the place where grass was located in the plots on C. plectostachyus on the variable voluntary forage intake.

A randomised block design was used to evaluated the effect of the periods of the year on L. leucocephala voluntary forage intake. Four repetitions were used to analyse the information. The relationship of forage digestibility and availability with voluntary forage intake were analysed through simple and multiple regression analysis. The effect of molasses inclusion on voluntary forage intake was also evaluated. Milk production of Lucerna breed cows, from the group of high production, was evaluated in both milking periods in different seasons of the year for one week.

On average cows were on the 108th day of lactation. There was a large variation on lactation days and age, consequently, milk production was adjusted for these factors. Adjustment for age was carried out with the factors reported by Duran (1976). To adjust for lactation days it was necessary to design correction factors for the Lucerna breed. This adjustment was made using a methodology recommended by Jaime Eduardo Muñoz, an statistics specialist from Colombian National University. Milk production was analysed using an unbalanced completely randomised design. Comparisons were also made between seasons with and without molasses supplementation.

Results

First semester

Animals spent more time grazing than browsing (78.9 and 21.1%, respectively, Table 1) and spent more time grazing during the day (57%) than during the night (43%) (P < 0.05) (Table 2). Browsing time was higher during the night than during the day. There was significant difference (P< 0.05) on the animal behaviour between seasons. Animals grazed and browsed more time on the moderate rainy season. Grazing and browsing time were similar between dry and wet season.

Voluntary intake of Leucaena and grass was also higher on the moderate rainy season than in the dry or wet season. The lowest forage voluntary intake was obtained on the dry season. Leucaena shrubs were pruned at the beginning of the dry season (Table 1).

On average milk production on this semester was 10.6 litres/cow/day and significant differences were found between seasons (P < 0.05). Milk production was similar between moderate and wet season and these in turn, were higher than in the dry season. Protein:energy ratio was calculated by the total dry matter intake and the contents of protein and energy in the forages. A negative protein:energy ratio during the dry season and a positive balance during moderate rainy and wet seasons were found (Table 1).

Second Semester

Animals spent more grazing than browsing (70.7 and 29.3%, respectively) and spent more time grazing during the day (60.74%) than during the night (39.25%) (Table 3). Browsing time was higher during the night than during the day (P < 0.05) (Table 4). There was significant difference (P< 0.05) on animal behaviour between seasons. Animals grazed and browsed more time on the moderate rainy season. Animals had a lower total activity on the wet season.

Voluntary intake of Leucaena and grass was higher on the moderate rainy season than in the dry and wet season. The lowest forage voluntary intake was obtained on the very rainy season (Table 3).

Milk production this semester was on average 11.6 litres/cows/day. Although there was a negative protein:energy balance during the wet season, there was not significant difference between seasons (P < 0.05) (Table 3).

On both semesters, grazing time was affected by the disposition of grass in the plot. Animals dedicated more time to graze C. plectostachyus located outside of the P. juliflora tree shade than to graze C. plectostachyus located under the shade.

There was a significant correlation between browsing time with Leucaena availability (r = 0.70 P< 0.05) and digestibility (r=0.74, P<0.05) throughout the year. In the same way, the time spent to graze C. plectostachyus outside the tree shade was correlated with forage availability and digestibility (r = 0.40 and 0.80, respectively. P < 0.05). However, the time spent to graze C. plectostachyus under P. juliflora trees was not correlated with grass digestibility (r = 0.03). Grass availability only explained 58% of the grazing time variation throughout the year (r = 0.76, R2 = 58%, P < 0.05).

Table 1. Evaluation of the silvopastoral system in different seasons of the year, without energy supplementation (molasses)

Season

Grass
availability

Leucaena availability

Grass
protein

Grass
digestbility

Leucaen
protein

Leucaen
digestibility

Grazing
time(h)

Browsing
time(h)

Grass
voluntar
intake(gr.)

Leucaena
voluntary
intake(gr)

Total
forrag
voluntary
intakegr.

Balance

Milk
production(lt)

Moderate
rainy

3.41

0.5

13.4

64.9

27.5

68.6

6.5 a

1.9 a

10.3 a

2.1 a

12.4 a

+

10.8 a

Wet

4.25

0.62

11.8

66.4

24.8

69.4

5.3 b

1.3 b

8.5 b

2.9 a

11.4 a

+

11.1a

Dry

2.21

0.23

12.3

64.7

26.4

67.8

4.9 b

1.2 b

7.3 b

1.1 b

8.4 b

-

9.8 b

Table 2. Grazing and browsing time (hours) during day and night, in different seasons of the year, without energy supplementation

Season

C.plectostachyus

L. leucocephala

Day

Night

Total

Day

Night

Total

Moderate rain

2.7

2.3

4.9

0.5

0.7

1.2

Wet

4.0

2.5

6.5

0.7

1.2

1.9

Dry

3.0

2.3

5.3

0.6

0.7

1.3

Table 3. Evaluation of the silvopastoral system in the second semester of the year with energy supplementation (molasses)

Season

Grass
availability

Leucaena availability

Grass protein

Grass digestbility

Leucaen protein

Leucaen digestibility

Grazing time(h)

Browsing time(h)

Grass voluntar intake(gr.)

Leucaena voluntary intake(gr)

Total forrag voluntary intakegr.

Balance

Milk production(lt)

Moderate
rainy

3.1

0.70

12.6

65.6

26.5

69.8

5.0 a

1.9 a

7.4 a

1.9 a

9.3 a

+

11.8a

Wet

2.4

0.60

11.3

64.1

26.3

68.5

2.7 b

1.5 b

4.5 c

1.7 b

6.2 c

-

11.4a

Dry

2.8

0.40

11.1

63.6

26.8

69.2

4.5 a

1.6 b

6.1 b

1.7 b

7.8 b

+

11.6a

Table 4. Grazing and browsing time (hours)during day and night, in the second semester of the year, with energy supplementation.

Season

C. plectostachyus

L. leucocephala

Day

Night

Total

Day

Night

Total

Moderate rain

2.9

2.1

5

0.68

1.2

1.88

Wet

1.78

0.92

2.7

0.55

0.89

1.44

Dry

2.7

1.75

4.45

0.6

0.95

1.55

Means

2.46

1.59

4.05

0.61

1.01

1.62

Discussion

The data on animal behaviour reported in this paper coincides with that reported in the literature. A higher grazing than browsing time in milk cattle has been reported with other plant species (Marquez et al., 1983). Diurnal grazing time has been reported to be higher than nocturnal (Senra et al.,1994; Hernández et al. 1995).

On the moderate rainy season of the first semester of the year, the higher grazing and browsing time and the higher forage voluntary intake could be attributed to a higher forage digestibility compared to the dry and wet season. Although, others factors like the time when the prune was conducted also could have affected the results obtained on the last seasons. During the wet season, a low grazing and browsing time was found. This is related to the fact that animals stopped their activities when it was raining that they did not like the wet and smeared grass. After the period of the day where there was heavy rain, animals only browsed Leucaena. The high availability of Leucaena on this season, provided a nutritious option in the silvopastoral system and the cows could have a higher forage intake compared with the dry season. The high availability of Leucaena might have avoid a decrease of the milk production during the wet season.

In the second semester of the year, when molasses was offered as a supplement, there was a higher grazing and browsing time and a higher forage voluntary intake on the moderate rainy season compared to the other periods.

Grazing time this season was affected by the availability of P. juliflora pods. Animals showed preference for the pods and spent more time grazing and searching for pods. On the wet season, grazing time and grass intake were more affected than in the first semester because the rainfall was higher. However, milk production was not affected. Again, a higher Leucaena availability represented a nutritious option in the silvopastoral system. This availability combined with the inclusion of molasses as a supplement had a positive effect on the milk production. Milk production increased to 1.1 litres/cow/day on the second semester. This could be explained by the presence of rapidly fermentable carbohydrate which increases the digestion of structural carbohydrates (Díaz (1991), this also affects positively the energy-use efficiency and consequently animal productivity (Owen, 1990).

Conclusions

Findings in this silvopastoral system suggest that in total, cows spend more time grazing than browsing. However this varies across the year, affected by factors like weather, the pruning, the time at which animals are introduced in the grazing paddock and the energy supplementation. The supplementation represented an important increment on milk production. This suggests the need for more studies about the strategic supplementation of animals in silvopastoral systems.

References

Díaz T. 1991. Nutrición proteica y energética en rumiantes. En: Segundo curso sobre avances en nutrición animal. Centro de investigaciones agropecuarias Tibaitatá, Colombia. p 83-111.

Duran C. 1976. Genetic and environmental parameters in the Lucerna herd of Cattle in Colombia. Tesis M.Sc. Faculty of North Carolina State of University at Raleigh. 153 p.

Giraldo L. 1996. Metodología para estimar el consumo bajo pastoreo. Documento de trabajo.Curso de profundización I. (Nutrición). Universidad Nacional, Medellín. 13 p.

Hernández D, Carballo M and García-Trujillo R. 1995. Efecto del tiempo de estancia en Guinea Likoni pastoreada con vacas lecheras. I. horas de pastoreo. Pastos y Forrajes. 18: 163-170.

Márquez J, Villalobos J and Chávez A. 1983. Hábitos de comportamiento del ganado bovino en un matorral de gobernadora (Larrea tridentata). Tesis Escuela Superior de Zootecnia, U.A.C.H. Chihuaua, México. 98 p.

Owen A. 1990. La fermentación de los carbohidratos en el rumen y sus implicaciones para la vaca lechera. Contribución del grupo bovinos del ICA en el II curso nacional de Ganado de leche. Facultad de Zootecnia, Universidad de Nariño, Colombia.

Senra A, Ugarte J, Diallo M and Galindo J. 1994. Hábito de pastoreo de vacas Holstein durante la época de lluvia con diferentes números de cuartones de pasto estrella (Cynodon nlemfuensis) con fertilización. Rev. Cubana Cienc. Agríc. 28: 273-280.

Steel RGD and Torrie JH. 1980. Principles and procedures of statistics. A biometrical approach. McGraw-Hill Int.Book Co. Tosho Printing Co, Tokyo, Japón. p. 622.

Kinetic of in situ disappearance and ruminal variable in sheep fed with foliage of Buddleia skutchii

Sanginés, G.L[234], Nahed, T.J[235], Sánchez, C.A[236]., Castillo, D. R.M[237]. and Pérez-Gil R.F[238].

Key words: ammonia, pH, rate passage, VFA’s

Introduction

The importance of the trees in the agrosilvopastoril systems bases in which maintain a continuous foliage production and satisfy multiple needs of the rural families. Buddleia spp belongs to the Loganiaceae family. It is known as tepozan and Tzelopat or Sac patej in Tzotzil. It is a shrub or tree of 2 to 20 meters of height, has a pantropical distribution, exist about 20 difference species in Mexico; it is found widely distributed, it grows in scrubs, grassland and forests, but preferably in the secondary vegetation and in places immensely disturbed, including urban zones (Rzedowski and Rzedowski,1985). It is developed in altitudes from 1500 to 3600 meters above sea level, is found preferably in wet or dry places, in the edges of the rocks and gullies in pine forests oak tree (Standley and Williams 1969). The main objective of this study was known the ruminal fermentation variables [pH, NH3 and volatile fatty acids (VFA’s)] as well as the disappearance in situ of the dry matter (DM) and crude protein (CP) of the Buddleia skutchii foliage combined with Pennisetum clandestinum (kikuyo grass) in diets for sheep.

Material and methods

The material was harvested from September 28 to October 7, 1998, in the Las Ollas community, Highlands of Chiapas. They were considered leaves and petiole of the strata under and middle of the glass of the trees in vegetative period and were dried at ambient temperature. The chemical evaluation of the Buddleia leaves, Penisetum clandestinum and of the diets were made through the chemical proximal analysis (A.O.A.C., 1995), fiber fractions (Van Soest and Wine, 1967 and 1968) and gross energy by calorimetric pump, pH and NH3 was measured with a potentiometer and VFA’s by gas chromatography (Erwin, 1969). The basal ration consisted of chopped P. clandestinum (control diet), since is the dominant kind in the grassland of the study region, and was beed substituting in 20, 40 and 60% by Buddleia skutchii. The diets were evaluated through the in vivo metabolic tests during 4 periods. They were employed 4 cannulated male lambs, criollo, adult with an average liveweight of 50 Kg., and housed in individual metabolic crates, in which stayed during all the study. It was determined the kinetic of pH, NH3 and VFA’s to 0, 3, 6, 9 and 12 h. The nylon bag technique (Orskov et al, 1980) was used to assess the in situ degradation of DM and CP; the periods of hatching were of 0, 3, 6, 9, 12, 24, 30, 36, 48 and 54 hours post pandrium, for this was used a model of kinetic of first order proposed by Waldo et al (1972) and was calculated continuing the recommendations of Singh et al (1992).

The experiment design was a 4 X 4 Latin square with four periods. Data were subjected to analysis of variance with the General Linear Model of SAS (SAS, 1985). The difference between means were determined by the Tuckey test (Gill, 1978), Statistical significance was declared at P<0.05.

Results and discussion

The results of the chemical analysis are reported in Table 1. It can be observed that the CP values and gross energy of B. skutchii are found within the ranges referred by the literature (Camacho et al, 1998; Jain et al, 1981 and Nahed et al, 1997a and b).

Table 1. Chemical composition of B. skutchii and P. clandestinum hay and their mixtures (g/100g).

Nutrient

B. skutchii

Control diet (T1)

Diet 1 (T2)

Diet 2 (T3)

Diet 3 (T4)

(g/100 g)


100% kikuyo grass

20% Tepozán

40% Tepozán

60% Tepozán

Crude protein

14.13

8.94

9.98

11.01

12.05

Ether extract

1.32

1.37

1.36

1.35

1.34

Ashes

4.65

12.38

10.83

9.29

7.74

Gross energy (Mcal/Kg)

3.53

2.37

2.46

2.55

2.64

NDF

62.31

66.78

65.88

64.99

64.1

ADF

55.51

46.01

47.91

49.81

51.71

Hemicellulose

6.80

20.77

17.97

15.18

12.39

Cellulose

34.85

30.72

31.54

32.37

33.2

Lignin

21.07

9.86

12.1

14.34

16.58

The values of pH in rumen liquor are in Table 2, those which were maintained in an average of 6.56 to 6.85 in the different diets, being the bottommost value in diet 1 to 12 h. The ruminal pH did not decrease of 6, what would favor a good digestibility of the diets, since are given the conditions of pH so that they could proliferate the cellulolytic ruminals bacterias. On the other hand, it is important to mention that in most of the diets the pH begins to reduce as of 6 hours, what makes to think that about that moment was presented the fermentation peak and was maintained until 12 hours, something which coincides with Van Soest (1982).

Table 2. Kinetic of ruminal pH in sheep fed with different levels of Buddleia skutchii

HOUR

CONTROL DIET

D1 (20% B.skutchii)

D2 (40% B. skutchii)

D3 (60% B. skutchii)

Prob

0

6.85

±0.41

6.62

±0.37

6.86

±0.07

6.81

±0.27

0.74

3

7.05

±0.20

6.90

±0.41

6.93

±0.20

6.81

±0.37

0.68

6

6.93

±0.21

6.60

±0.54

6.70

±0.19

6.55

±0.25

0.39

9

6.78

±0.13

6.58

±0.55

6.48

±0.16

6.42

±0.31

0.45

12

6.66A

±0.19

6.11B

±0.40

6.21AB

±0.16

6.35AB

±0.32

0.08

Prob

0.29


0.25


0.01


0.15



Mean

6.85A

±0.26

6.56B

±0.48

6.64B

±0.31

6.59B

±0.33


AB means with different superscripts with a row are significantly different (P<0.05)

The greater rumen ammonia concentration for all the diets was found between 3 and 6 hours (Table 3), something which coincides with the greater in rumen microbial fermentation and the digestion diets with high forage content. The present values in rumen were above the concentration suggested by Satter and Slyter (1974) being of 5 mg/100 ml for enough to support maximum growth rates of rumen bacterias. The precise limiting concentration is perhaps closer to 2mg/100ml, but use of the higher value gives a slight margin of excess, up to 80 mg of NH3/100 ml, did not inhibit microbial growth. In Diet 3 were presented the values but low; the mean was of 4.10 mg/100 ml, however to the hours 9 and 12 the concentration was between 2.04 and 1.56 mg/100m, what would deal reflected in the digestibility of the crude protein.

Table 3. Kinetic of ruminal ammonia (N-NH3,mg/100ml) in sheep fed with different levels of B. skutchii

HOUR

CONTROL DIET

D1 (20% B.skutchii)

D2 (40% B. skutchii)

D3 (60% B. skutchii)

Prob

0

8.12

±1.94

6.84 ab

±23.03

5.47 ab

±3.04

3.94ab

±0.73

0.22

3

13.47

±6.61

16.82 c

±67.86

12.64 c

±4.55

7.53ª

±3.53

0.14

6

13.92 A

±6.65

14.35A bc

±32.15

10.16 A bc

±2.27

5.05 Bab

±2.73

0.04

9

8.81 A

±1.11

8.29Aabc

±91.20

5.18 Aab

±1.40

2.04 Bb

±2.07

0.04

12

7.2 A

±4.17

3.46AB a

±23.94

3.00B ab

±1.28

1.56Bb

±1.49

0.07

Prob

0.18


0.002


0.001


0.019



Mean

10.31 A

±5.06

9.95 AB

±6.18

7.29 B

±4.40

4.10 c

±2.98


AB means with different capital letter superscripts with a row are different (P<0.05) and small letter superscripts (abc) between lines area significantly different

In relationship to the VFA’s production, it can be mentioned that the acetic, propionic and butiric (mM/1) were increased significantly (P<0.05), accordant was increased the percentage of Buddleia in the diet (Table 4). The average proportion in percentage of volatile fatty acids in the rumen was of 51.6, 33,19 and 10.64 for the acetic, propionic and butiric respectively, presenting a fundamentally acetic fermentation, characteristic of diets to forage base (Figure 1).

Table 4. Volatile Fatty Acids production in rumen of sheep fed with different levels of Buddleia skutchii.

VFA’s
(mM/l)

Control diet (T1)
00% kikuyo grass

Diet 1 (T2)
0% Tepozán

Diet 2 (T3)
0% Tepozán

Diet 3 (T4)
60% Tepozán

Acetic

1.22.049 A

2.45.091B

1.45.163AB

2.82.049B

Propionic

0.57.11ª

1.36.040B

0.70 0.29AB

1.34.05B

Butiric

0.150.012ª

0.31.082AB

0.21.017AB

0.46.05B

AB means with different superscripts with a row are significantly different (P<0.05)

Figure 1. Relation of volatile fatty acids in the rumen of sheep fed with differente levels of B. skutchii

In table 5 are presented the results of kinetic of rumen DM and CP digestion. Can be observed that the fermentation time predetermined the indigestible fraction on the digestion rate and time of 48 hours underestimated the potentially digestible fraction. Ku et al (1998) and Kibon and Orskov (1993) reported rates of digestion (Kd) by hour from.022 until.081 for foliage of different kinds of trees and shrubs. The results of Kd for DM in this case were of.033 to.045 h-1. It is important point out that accordant was increasing the percentage of FBS in the diets, increased also the potentially digestible fraction of the crude protein and the digestibility of the same in rumen, however, the undegradable fraction was superior to the 60% in all diets.

Table 5. Kinetic of rumen DM and CP disappearance of diets elaborated with Kikuyo grass (P. clandestinum), and supplemented with different levels of B. skutchii foliage*.


EXPERIMENTALS DIETS

In situ degradation oC dry matter

0% Buddleia

20% Buddleia

40% Buddleia

60% Buddleia

24 hours (%)

24,14

23,02

19,82

21,23 ±6,43

48 hours (%)

34,18

33,64

33,39

34,53 ±8,04

CONSTANTS OF DIGESTION MODEL

D.M

C.P

D.M

C.P

D.M

C.P

D.M

C.P

Potentially digestible fraction (b) (%)

32.13

13.48 A

31.54

19.55 B

29.72

21.29 AB

32.79

34.82 B

Rapidly soluble fraction (a) (%)

5.54

17.35 A

5.34

3.49 B

6.17

7.85 AB

5.9

4.45 B

Undegradable fraction (100-(a+b)) (%)

62.29

69.16 A

63.,1

75.95 A

64.09

70.85 A

61.29

60.69 B

Rate constant of degradation (c) (h-1)

0.006


0.007


0.006


0.007


Rate of digestion (Kd) (h-1)

.0405

.038

.0407

.038

.033

.030

.0454

.059

Rate of passage (Kp) (h-1)

.069

.070

.077

.076

,071

.070

.062

.060

Digestibility (Kd/(Kd+Kp)) (%)

36.98

32.31 A

34.58

32.90 A

31.73

20.06 A

42.27

47.10 B

* Exponential Equation p = a+b (1 - e-ct)
No significant (P>0.05) differences were detected in DM
AB means with different superscripts with a row are different (P<0.05)

Conclusions

Of the previous results can be concluded that until a 60% of kikuyo grass substitution in the diet improves the same quality, increase the quantity of CP, enhance the in situ digestibility of DM and CP, without be affected the ruminal fermentation parameters; therefore the foliage of Buddleia skutchii constitutes an alternative that would be contribute to reduce the pressure of the grasslands in the conditions of the current managing of the ovine production systems practiced by the Tzotzil indigenous people in the Highlands of Chiapas, to encouraged his systematic utilization.

References

A.O.A.C. (1995): Official Methods of analysis. Association of Official Agirucltural Chemist: 15th ed. Washington, D.C.

Camacho, M.D., Nahed, T.J., Soto P.L., Jiménez F.G., Ochoa G.S. y Grande C.D. (1998): Conocimiento local y valor nutritivo del género Buddleia en Los Altos de Chiapas. Agrociencia, 32: 403-412.

Erwin, E.S.; Marco, G.J. y Emery, E.M. (1969): Volatile fatty acid analyses of blood and rumen fluid by gas chromatography. J. Dairy Sci., 44: 1768-1771.

Gill, J.L. (1978): Design and Analysis of Experiments in the Animal and Medical Science. The Iowa State University, U.S.A.

Jain, R.K., Garg, V.K. y Khanduja, S.D. (1981): Macronutrient element composition of leaves from some ornamental shrubs grown on normal and alkali soils. J. Horticultural Sci. 56 (2): 169-171.

Kibon, A. y Orskov, E.R. (1993): The use of degradation characteristics of browse plants to predict intake and digestibility by goats. Anim. Prod. 57: 247-251.

Ku, V.J.C., Ramírez, A.L, Jiménez F.G., Alayón, J.A. y Ramírez C.L. (1998): Arboles y arbustos para la producción animal en el trópico mexicano. Conferencia electrónica de la FAO sobre agroforestería para la producción animal en Latinoamérica. Agrofor1: Artículo No. 10.

Nahed, T.J.; Grande, C.D.; Sánchez C.A.; Martínez, V.A; Pérez-Gil, R.F.; Sanginés, G.L.. y Carmona, T.J. (1997a): Contribución al desarrollo de sistemas agrosilvopastoriles en Los Altos de Chiapas. II. Valor nutritivo, producción de follaje de especies leñosas forrajeras y respuesta de ovinos. Gestión de Recursos Naturales No. 8: 45-53.

Nahed, J.; Villafuerte,.L.; Grande, D.; Pérez-Gil, F.;Alemán, T. y Carmona J. (1997b): Fodder shrub and treee species in the Highlands of southern Mexico. Anim. Feed Sci. And Thech. 68: 213-223.

Rzedowski, J. y Rzedowski G. (1985): Flora fanerogámica del Valle de México, Volumen I. 1a. Ed. Escuela Nacional de Ciencias Biológicas. Instituto Politécnico Nacional e Instituto de Ecología, México.

SAS: SAS/STAT guide for personal computers, version 6 edition. SAS Institute Inc. Cary, N.C. 1985.

Satter, L..D. y Slyter. L.L. (1974): Effect of ammonia concentration on rumen microbial protein production in vitro. Br. J. Nutr. 32: 199-208.

Singh, B., Makkar H.P.S. y Negi, S.S. (1992): The kinetics of digestion in ruminants. A review. Indian J. Dairy Sci. 46 (3): 90-99.

Standley, C.P. y Williams, O.l.L.(1969). Loganiaceae. En:Gibson N.D. Flora de Guatemala. Fieldiana: Botany Vol. 24. Part VIII.

Van Soest, P.J(1982): Nutritional ecology of the ruminant. O & B Books, Inc., USA.

Van Soest, P.J. and Wine R.H. (1967): Use of detergents in the analysis of fibrous feeds. IV. Determination of plant cell wall constituents. J.A.O.A.C. 50: 50-55.

Van Soest, P.J. and Wine R.H. (1968): Determination of lignin and cellulose in acid detergent fibre with permanganate. J.A.O.A.C.: 51: 780-785.

Waldo, D.R., Smith, L.W. y Cox, E.L. (1972): Model of cellulose disappearance from the rumen. J. of Dairy Sci. 55: 125.129.

Use of mulberry (Morus alba) as ruminant feed

Jorge Benavides[239]

Introduction

Nutritional value

Mulberry is known for its high crude protein (CP) content, along with high energy levels, good mineral composition, and low fiber values. In Costa Rica dry matter (DM) ranges between 25 and 32% for the leaves; between 23 and 29% for non-ligneous stems; and between 24 and 45% for woody stems (Benavides et al., Espinoza, 1996). In different ecological regions of Costa Rica, with varying fertilization levels, the content of DM, CP, and IVDMD in leaves, and in the edible portion of the stems, were much more affected by the edaphic and climatic conditions (site), than by fertilization levels, and there were no significant differences between varieties. Mulberry has CP values between 15 and 25%, and IVDMD values between 75 and 90% (Table 1). The woody stem has good bromathological quality, with CP values ranging between 7 and 14%, and IVDMD values between 56 and 70% (Benavides et al., 1994; Espinoza, 1996; Rojas et al., 1994). The above-mentioned studies, reported a marked site effect due to soil and climatic conditions. In Paquera, Costa Rica’s Pacific Coast, with higher radiation and temperature, the PC and IVDMD values were lower (15.5 and 71.1% respectively), in comparison with sites at higher elevation, which had higher cloudiness and lower temperatures, as is the case of Coronado and Puriscal, located in the Costa Rican highlands (Espinoza 1996). N, P, and Ca of the leaves and non-ligneous stems are high, respectively (Espinoza, 1996).

Table 1. Bromathological composition of Mulberry foliage according to variety, pruning, site, level, and type of fertilization.

Variety

% DM

% CP

IVDMD

% N

% P

% K

% Ca

Criolla

29,1b

19,8a

75,0a

3,17

0,30

2,07

1,90

Indonesia

31,2a

21,1a

73,5a

3,37

0,30

1,73

2,87

Tigriada

28,3c

20,1a

74,7a

3,23

0,40

2,33

2,74

Fertilization








Manure, 480 kg N/ha/y2

25,5d

20,2b

76,9





NH4NO3, 480 kg N/ha/y

25,6cb

22,5a

77,1













NH4NO3, 180 kg N/ha/y3

29,8a

19,9a

74,2ª

3,18

0,33

1,96

2,54

NH4NO3, 360 kg N/ha/y

29,7ab

20,4a

74,2ª

3,26

0,33

2,05

2,49

NH4NO3, 540 kg N/ha/y

29,1b

20,7a

74,8ª

3,32

0,33

2,12

2,48

Site








Puriscal

31,4b

21,1b

76,7ª





Coronado

24,9c

24,8a

74,9ª





Paquera

32,3a

15,1c

71,5b





Mulberry silage

28.4

17.2

66.3





Live digestibility (goats)



79.3





Animal response

Oviedo (1995), comparing Mulberry foliage with concentrate (Table 2) as supplement for Jersey x Criollo cows, that were grazing, obtained similar levels of milk production (12.1 y 111.9 kg/an/day, respectively) for each supplement, at equal levels of DM consumption (1.0% of live weight), and above that with just grazing (11,3 kg/an/day). The use of Mulberry in the diet did not affect the content of fat, protein, and total solids of the milk, but it improved the net benefit in comparison with concentrate (US$ 3.29 vs. $2.84, respectively). Esquivel et al. (1996), substituting 40 and 75% of the concentrate with Mulberry foliage did not find significant differences (p<0,05) in milk production (14.2; 13.2 y 13.8 kg/an/day, respectively) of Holstein cows grazing Kikuyo (Pennisetum clandestinum), nor apparent effects in the quality of the milk. Considering only the feeding costs, the net income per animal was 11.5% higher with the maximum level of Mulberry than to the one obtained with only concentrate supplementation.

In hybrid milk goats of 40 kg of live weight, Rojas et al. (1994) found milk increments of 2.0 and 2.5 kg/an/day when the Mulberry supplement increased from 1.0 to 2.6% of the live weight on a dry basis and small increases in the contents of fat, protein, and total solids of the milk. In this experiment, it is noteworthy the high intake of total DM, and the additive effect that the addition of increasing amounts of Mulberry on the diet had on that intake. The authors also observed a sharp substitutive effect on the intake of DM of the King-grass.

Table 2. Milk production and intake of cows and goats fed with grass and Mulberry foliage.

Species

Milk
Kg/a/day

Intake DM, %LW

Mulberry

Grass

Concentr

Total

Cows (Jersey x Criollo)

12.1

1.0

2.4

-

3.4

Cows (Holstein)

13.8

1.2

1.8

0.4

3.4

medium potential goats

2.5

2.6

2.6

-

5.2

high potential goats

3.4

2.5

3.0

-

5.5

Goats with Mulberry silage

1.9

4.9

-

-

4.9

In a 3-year evaluation, in an agroforestry module with goats fed only with similar amounts (3.0% of live weight on a dry basis) of King-grass (P. purpureum x P. typhoides), and Mulberry, Oviedo et al. (1994) reported close to 900 kg of milk/an/lactance of 300 days. This is equivalent to an average production of 3.0 kg/an/day, and a 4.1 kg/an/day at the beginning of the laitance. The animal feed came exclusively from an 1100 m2 area of Mulberry and grass planted in association with Poró (Erythrina poeppigiana), fertilized with animal manure, plus the Poró biomass, and residues from the feeders. In the third year, milk production from the module reached 0.5 kg/day, which amounts to 16500 kg/ha/yr. The cash-flow financial analysis showed a benefit/cost ratio of 1.27, 1.39, and 1.45 for each year, respectively.

In the humid tropics of Turrialba, with Jersey x Criollo dairy cows grazing Cynodon nlemfuensis, and supplemented with concentrate, or Mulberry, there were no statistical differences (p<0.05) in weigt gain between supplements (Table 3; Oviedo and Benavides, 1994). Confined young Creole Romo-sinuano bulls, with a diet of Elephant-grass (Pennisetum purpureum) gained the following weights: 40, 690, 940, 950 g/an/day with DM supplemental consumption of whole Mulberry of 0, 0.90, 1.71, and 2.11% of their live weight (González et al, 1996). In this study, the partial budget analysis gave an income/cost ratio of 0.10, 1.11, 1.18, and 0.97 for each level of weight gain, respectively.

In Black-belly Sheep with a basal diet of King-grass, weight gains were 60, 75, 85, and 101 g/an/day when Mulberry was supplemented at 0; 0.5; 1.0; and 1.5% of live weight on a dry basis, respectively (Benavides, 1986). This study did not find a substitutive effect over the intake of grass DM, but it found a strong additive effect over the consumption of total DM (Table 3).

Table 3. Weight gain and intake of ruminants and sheep fed with grass and Mulberry foliage.

Type of ruminant

WG

Intake DM, % LW

Mulberry

Grass

Total

Romosinuano steers (Fresh Mulberry)

0.94

1.71

1.29

3.00

Romosinuano steers (Mulberry silage)

0.60

1.05

1.56

2.61

Young cows Jersey x Criollo

0.60

1.00

Grazing


Black-belly sheep

0.10

1.50

2.84

4.34

Agronomy

Since Mulberry extracts significant amounts of nutrients from the soil, the use of organic fertilizer (mulch and manure) has been emphasized as a nutrient source. Under conditions of the Costa Rican humid tropics, for three years, a Mulberry plantation with a density of 22500 plants/ha, produced over 35 tons DM/ha/year (Table 4) using goat manure as fertilizer (Benavides et al., 1994). In addition, production was 20% higher with manure than with ammonium nitrate in equivalent N amounts, evidently as a result of the presence of other mineral nutrients in the manure. There was an increase of 10% between years in the yield of total DM, reaching in the third year a production of 38 tons of DM/ha.

In Costa Rica, working with three Mulberry varieties (Criolla, Indonesia, and Tigriada), at three sites (Puriscal, Coronado, and Paquera), Espinoza et al. (1996) reported important differences between varieties in yield of total DM. One of them had practically half the yield reported for the other two (14.1; 22.3, and 25.4 tons/ha/yr for each variety, respectively). The same authors detected important differences in yield, attributed to edaphic and climatic factors, and to the level of N applications to the soil.

In Paquera, despite long dry seasons and less fertile soils, the average production of all the varieties (31.2 tons DM/ha/yr), duplicated the one in Coronado (15,5 tons DM/ha/yr), where it rains year-round. This is attributed to the higher radiation, and higher temperatures of Paquera, and to the higher cloudiness, and lower temperature of Coronado, located in a mountainous area, as mentioned in the section on nutritional value. Despite this, differences between sites were reduced when biomass was evaluated in terms of edible DM.

Conclusions

High levels of crude protein and digestibility greatly surpass the ones from the most commonly used tropical forages, and are only comparable to the ones reported for concentrates. Mulberry plants exhibit high regrowth capability, and survival rates above 98% after being planted for two years. Results show that, with good fertilization, Mulberry can produce good edible biomass levels per unit area.

With adequate fertilization, yield increases through the years, just as the cited literature reports. Manure additions produce higher biomass per unit area than ammonium nitrate, due to the addition of other elements, and to its effect on the soil’s physical properties. Even though Mulberry is a good extractor of soil nutrients, it is very efficient in nutrient utilization when they are added as organic fertilizer, particularly in the case of N. Nutrient production is higher with more frequent pruning, but the adequate interval must be evaluated according to the soil’s conditions, fertilization, and rainfall at each site.

Table 4. Production of dry matter and leaf/stem ratio of Mulberry according to variety, age, site, and level and type of fertilization.

Variety

Yield, t DM/ha/y

Leaf/stem Ratio

Criolla

14,1c

1,00a

Tigriada

22,3b

0,57c

Indonesia

25,4a

0,81b

Site



Puriscal

15,2b

0,82b

Coronado

15,5b

0,99a

Paquera

31,2a

0,57c

Age, years






1

31,1


2

33,4


3

38,2


Fertilization



Manure, 180 kg. N/ha

16,1b

0,83a

Manure, 360 kg. N/ha

21,6a

0,78b

Manure, 540 kg. N/ha

24,1a

0,77b




NH4NO3, 0 kg N/ha/y

22,9d


NH4NO3, 240 kg N/ha/y

28,2c


NH4NO3, 360 kg N/ha/y

32,6b


NH4NO3, 480 kg N/ha/y

38,2a


References

BENAVIDES, J.E. 1986. Efecto de diferentes niveles de suplementación con follaje de morera (Morus sp.) sobre el crecimiento y consumo de corderos alimentados con pasto (Pennisetum purpureum). In: Resumen de las investigaciones realizadas con rumiantes menores, cabras y ovejas. Proy. Sistemas de Producción Animal. CATIE, Turrialba, C.R. 1986. Serie Técnica. Inf. Técnico No. 67, pp. 40-42.

BENAVIDES, J.E. 1991. Integración de árboles y arbustos en los sistemas de alimentación para cabras en América Central: un enfoque agroforestal. El Chasqui (C.R.) No. 25:6-35.

BENAVIDES, J.E.; LACHAUX, M.; FUENTES, M. 1994. Efecto de la aplicación de estiércol de cabra en el suelo sobre la calidad y producción de biomasa de Morera (Morus sp.). In: J.E. Benavides ed. “Árboles y arbustos forrajeros en América Central”. Vol. II. Serie técnica, Inf. técnico No. 236. Turrialba, C.R. CATIE. pp. 495-514.

ESPINOZA, 1996. Efecto del sitio y de la fertilización nitrogenada sobre la producción y calidad de la biomasa de tres variedades de Morera (Morus alba). Tesis Mag.Sc. Turrialba, C.R., CATIE. 86 p.

ESPINOZA, E.; BENAVIDES, J.E. 1996. Efecto del sitio y de la fertilización nitrogenada sobre la producción y calidad del forraje de tres variedades de Morera (Morus alba L.). Agroforestería de las Américas (CATIE) (Jul-Dic. 1996). V. 3(11-12) p. 24-27.

ESQUIVEL, J.; BENAVIDES, J.E.; HERNANDEZ, I.; VASCONCELOS, J.; GONZALEZ, J.; ESPINOZA, E. 1996. Efecto de la sustitución de concentrado con Morera (Morus alba) sobre la producción de leche de vacas en pastoreo. In: Resúmenes. Taller Internacional “Los árboles en la producción ganadera”. EEPF “Indio Hatuey”, Matanzas, Cuba. p. 25.

GONZALEZ, J.; BENAVIDES, J.E.; KASS, M.; OLIVO, R.; ESPERANCE, M. 1996. Evaluación de la calidad nutricional de la Morera (Morus alba L.) fresca y ensilada, con bovinos de engorda. Agroforestería de las Américas (CATIE). (Jul-Dic. 1996). V. 3(11-12) p. 20-23.

OVIEDO, F. J.; BENAVIDES, J.E.; VALLEJO, M. 1994. Evaluación bioeconómica de un módulo agroforestal auto sostenible con cabras lecheras en Turrialba, Costa Rica. In: J.E. Benavides ed. “Árboles y arbustos forrajeros en América Central”. Vol. II. Serie técnica, Informe técnico No. 236. Turrialba, C.R. CATIE. pp. 601-630.

OVIEDO, F.; BENAVIDES, J.E. 1994. Utilización del follaje de Morera (Morus sp.) en la suplementación de vacas y terneras de lechería en pastoreo. In Memorias Taller Internacional sobre Sistemas Silvopastoriles en la Producción Ganadera. Estación Exp. de Pastos y Forrajes “Indio Hatuey”, Matanzas, Cuba, 13-15 Dic. 1994. p. 18.

OVIEDO, J.F. 1995. Morera (Morus sp.) en asocio con Poró (Erythrina poeppigiana) y como suplemento para vacas lecheras en pastoreo. Tesis Mag.Sc. Turrialba, C.R., CATIE. 86 p.

ROJAS, H.; BENAVIDES, J.E. FUENTES, M. 1994. Producción de leche de cabras alimentadas con pasto y suplementadas con altos niveles de Morera. In: J.E. Benavides ed. “Árboles y arbustos forrajeros en América Central”. Vol. II. Serie técnica, Informe técnico No. 236. Turrialba, C.R. CATIE. pp. 305-320.

SKERMAN, P.J.; CAMERON, D.G.; RIVEROS, F. 1991. Leguminosas forrajeras tropicales. Roma, FAO. 707 p.

SKERMAN, P.J.; RIVEROS, F. 1992. Gramíneas tropicales. Roma. FAO. 850 p.

STOBBS, T.H. 1975. Factors limiting the nutritional value of grazed tropical pastures for beef and milk production. Tropical Grasslands 9(2): 141-150.

The value of trees as fodder for livestock in orthern Namibia

Sikhalazo Dube[240], Carlos Salinas[241] and Oswin Mukulu[242]

Key words: communal areas, dry season, indigenous trees

Introduction

The major problem affecting livestock farmers in the Northern communal of Namibia is the shortage of fodder especially during the dry season and critical during droughts, which are frequent. The main option available to livestock owners is to increase the utilization of browse. Browse can be a major constituent of livestock diets supplying palatable and nutritious material when the grasses have long dried (Everson 1997). It is often the only green material available to animals during the dry season (Rees 1974, Sibanda 1986). Various parts of trees are utilized as animal feeds; the fruits provide high quality fodder (Walker 1980, Miller 1995). In most parts of Namibia due to the high stock numbers there is a general deterioration of the rangelands, which leads to increased dominance of woody species.

The ability of the trees to continue to grow into the dry season and to fix nitrogen is important in areas where acute fodder shortages are experienced (Ong et al. 1991). Over the past 4 years agroforestry has been an active engagements for the agricultural research and extension departments of the Ministry of Agriculture, Water and rural Development in communal areas of northern Namibia. This has happened while there has been concerns that trees will reduce underground water supply and grass production. The management of natural resources and exotic plantations is, therefore, vital, requiring the support of people who utilize them for it to be sustainable.

In this paper we present the value of indigenous trees as livestock feed as recounted by the local community.

Methodology

Study area

Ontanda village in Uukwaluudhi, Omusati region of Northern Namibia was selected for the study. Omusati is one of the four regions that constitute the northern part of Namibia, which was formerly known as Ovamboland. 13 % of the country's population about 189 919 people are found in the Omusati region. The region is completely rural with over 80% of households lacking basic facilities (NFFP 1998). Due to population growth and thus increase in settled areas there is evidence of degradation such as massive deforestation, overgrazing and a decline in arid land soil fertility.

North Central Division of Namibia received erratic rainfall. The long term annual mean rainfall of 380 mm. Over 90% of the rain fall during the JFM period (Beyer and Katsiambirtas 1987). The mean monthly temperatures are high (max. 30.5 degrees Celsius and min. 15.9 degrees Celsius). This results in very high evapotranspiration, long term annual mean evapotranspiration is 2 500 mm. This means that most of the rainfall that is received is lost into the atmosphere rendering rain fed crop production difficult and irrigation very expensive. Livestock production is thus an important farming activity for the region. The soils of the region are deep Kalahari sands. However the are patches of solonetz, non-solonetz with calcrete and aeolian sands. The clay content in most of the soils of the region is less than 10%.

Participatory approach

A participatory approach was adopted to gather data on the types of trees considered being important as livestock fodder by the community. Determining the woody species composition in the area along transects followed this exercise.

Results and Discussion

The farmers whilst possessing a high level of knowledge of the value of trees as livestock feed especially during bottle neck periods indicated little knowledge of how to manage the resource (Table 1 and 2). There where, however, a few trees within the cropping area and homestead, which were protected mainly due to their value, as sources of fruits or shade. The lack of a deliberate effort to manage the communal forest has led to indiscriminate cutting down of trees for fencing and fire hood a situation, which is threatening the survival of both livestock and people. This is also leaving the soils exposed mainly to wind erosion.

Table 1. Ten most important browse species and plant parts preferred by cattle

Woody species

Palatability

Preferred plant parts

Young leaves

Shoots

Leaves

Fruits

Bark

Flowers

Baphia massaiensis

More Palatable

1

2

1

3

4

5

Terminalia prunioides

1

2

1

3

4


Commiphora africana

1

3

2

4

4


Combretum imberbe

2

2

1

4

3


Combretum apiculatum

2

3

1

4

5


Hyphaena petersiana

2

3

2

4

5


Boscia albitrunca

3

1

1

5

4


Acacia erioloba

2

3

1

1

3


Lonchocarpus nelsii

2

3

1

4

5


Albizia anthelmintica

2

3

1

3

4


Combretum collinum

Less palatable

2

3

1

3

4


Numbers indicate level of preference at a sliding scale with one being the most preferred and 5 least preferred plant part

Table 2. Ten most important browse species and plant parts preferred by goats

Woody species

Palatability

Preferred plant parts

Young leaves

Shoots

Leaves

Fruits

Schinziophyton rautanenii

More Palatable

1

2

3

4

Acacia erioloba

2

4

1

3

Baphia massaiensis

4

2

3

1

Terminalia prunioides

2

3

1

4

Terminalia sericea

2

3

1

4

Sclerocarya birrea

2

4

1

3

Commiphora africana

2

3

1

4

Combretum imberbe

2

3

1

4

Lonchocarpus nelsii

2

4

1

3

Combretum collinum

2

3

1

4

Colophospermum mopane

Less palatable

2

3

1

4

Numbers indicate level of preference at a sliding scale with one being the most preferred and 5 l east preferred plant part

Conclusion

The value of trees as direct and supplementary feed for livestock in semi-arid environment can not overemphasized. It is therefore important that communities are made aware of the value, which might elude them unless deliberate steps are taken to manage these resources. Farmers should be encouraged to grow trees within their cropping areas, especially, nitrogen fixing species such as Leucena leucocephala, which also provide good forage for livestock. Efforts aimed at facilitating the formulation of feeds from indigenous trees without causing environment damage should be stamped up. Unless communities realize the direct benefits from trees conservation efforts will fail.

References

Beyer JJ and Katsiambirtas EE (1987) Climate of Ovambo: A Preliminary Report. Ministry of Works, Transport and Communication.Windhoek

Everson TM (1997). The effects of the introduction of agroforestry species on the soil moisture regime of traditional cropping systems in rural areas WRC Progress Report

Miller M (1995) Dispersal of Acacia seed by ungulates and ostriches in an African savanna. Journal of Tropical Ecology 12: 345-356

Namibia-Finland Forestry Project (1998) Institutional and Financial Schemes for Community Participation in Forestry Management

Ong CK, Odongo JCW., Marshall F and Black CR (1991) Water use by trees and crops. Agroforestry Today 2: 7-9

Rees WA (1973) Preliminary studies into bush utilization by cattle in Zambia. Journal of Applied Ecology 11: 207-214

Sibanda R (1986) The browsing and general behaviour of indigenous goats in thornveld Zimbabwe Agricultural Journal 83: 209-214

Walker BH(1980) A review of browse and its role in livestock production in southern Africa. In: Le Houéru HN (ed.) Browse in Africa. International Livestock Centre for Africa (ILCA) Addis Ababa pp 7-24

Dietary supplementation with saponins to improve rumen function and animal performance in the tropics

Alberto Navas-Camacho, Javier Cortes-Cortes and Edward Gutierrez-Mindiola

Introduction

Nutritional status of grazing ruminants depend basically upon rumen production and balance of volatile fatty acids and microbial protein. The physiological status of greatest economical importance (i.e. early growth, late gestation an early lactation) demand a large amount of amino acids which are not fulfilled by the flow of rumen microbial protein to duodenum. However, this protein flow accounts for only 50% of the rumen potential to produce and export microbial protein to duodenum (Nolan and Stachiw, 1979). The presence of rumen ciliate protozoa reduces the nitrogen economy for the ruminant (Leng, 1990) by means of increasing significantly nitrogen recycling into the rumen compartment (Coleman, 1989).

Defaunation has proved to be an alternative to increase the flow of microbial protein to the duodenum (Leng, 1990; Navas, 1990). However, so far there are not commercial alternatives to defaunate ruminants at the farm level. Therefore, a different approach, a drastic reduction by means of using saponins present in leaves and fruits from different trees has been recently evaluated (Navas et al., 1984; Diaz et al, 1993; Teferedegne et al, 1999). The present experiment aimed at evaluating rumen function and behavior of defaunated sheep and sheep supplemented with saponins from natural sources and fed on low quality forages.

Materials and Methods

The experiment was carried out at TIBAITATA, a national research center of CORPOICA (Corporacion Colombiana de Investigación Agropecuaria) located at 2600 above sea level. It was used 16 sheep, 8 months old, 25 Kg LW fitted with permanent rumen cannula. The animals were allocated into metabolic cages inside an animal house. To evaluate rumen function it was measured circadian change of rumen pH (A.O.A.C. 1990), effective degradability of FDN and protein following the procedure described by Orskov and McDonald (1979), rumen volume and dilution rate using a single dose of Cr-EDTA and taking samples for a 24-hours period (Binnerts et al, 1962), estimation of population size of ciliate protozoa (Dehority, 1984), zoospores and sporangia following the techniques described by Joblin (1981) and Ushida et al (1989) respectively, and viable cellulolytic bacteria following the procedure described by Leedle et al.(1982) and Cecava et al (1990). Liveweight change and voluntary feed intake were also measured.

Animals were fed on a diet based on wheat straw offered ad libitum and supplemented with (g/animal/d): sorghum grain (200), molasses (100), cottonseed meal (5% dry matter intake), urea (2% of dry matter intake) and a mineral mix (20). Clean and fresh water was offered ad libitum. For a 11-week period three fauna status were evaluated: defaunated animals (Defauntaed group), animals with the ciliate population reduced (Michu groups) and normal fauna (Control group). Fruits of Michu (Sapindus saponaria, 36% saponins; CORPOICA) were used at two levels (2g/Kg LW; Michu-2 group) and 4g/Kg LW; Michu-4 group) were used to get the rumen ciliate population reduced. To defaunate the animals the procedure described by Burggraff y Leng (1980) was followed. It was used a complete randomized design with four treatments and four replicates per treatment. Analysis of variance using PROC GLM of SAS (SAS, 1986) was carried out for evaluating the parameters. For those variables evaluated during several periods of time, the REPEATED MEASURE ANALYSIS of SAS (SAS, 1986) was used.

Results and Discussion

Voluntary Feed Intake

Feed intake was not affected by the inclusion of the low level (2g/Kg LW) of fruits used in this experiment (Table 1). Similar results were reported by Navas et al. (1994) and Diaz et al. (1993). However, at the high level (4g/Kg LW) 3 out of 4 animals showed a drastic reduction in their feed intake and had liquid faeces. Those animals had to be removed from the experiment. The irritant effect of saponins on the epithelium of digestive tract may account for the diarrhea and reduced feed intake found in these animals.

Liveweight Gain

It appears that the strong reduction of cilitate protozoa obtained through supplementation of sheep with saponin-containing fruits (Table 2.) increased the flow of bacterial nitrogen to duodenum, which allowed animals to grow faster (Table 1). Sheep supplemented with ca. 32400 ppm saponins had a daily gain 41.6% greater (P<0.05) than the Control group. The growth rate of defaunated animals, despite being higher than the CONTROL and MICHU-2 groups, did not show a linear trend because it was necessary to carry out the defaunation procedure twice during the experiment due to protozoa contamination in two animals which, obviously, affected the animal performance in a short period of time.

Table 1. Voluntary feed intake and live weight gain in defaunated, ciliate population reduced (MICHU-2) and normal fauna sheep fed on a wheat straw basal diet.


Voluntary Feed Intake
(% LW 0.75)

Live weight gain
(g/d)

CONTROL

3.37

27.49b

MICHU-2

3.34

38.93a

DEFAUNTATED

3.71

31.17a

Values in the same column with different subscripts differ significantly (P<0.05).

Makkar et al. (1998) reported that in efficiency of microbial synthesis was improved in vitro by adding three different sources of saponins to the media. However, Hristov et al. (1999) found no effect of supplementing 86.2 and 256 ppm of saponins from extract of Yucca shidigera on the flow of microbial protein to the rumen. It is likely that a positive response of bacterial flow may be obtained if there is a drastic reduction of ciliate protozoa. Makkar (1998) reported a reduction of ciliate protozoa of 64%, similar to the values found in this experiment and that of Diaz et al. (1993). The experiment of Hristov et al (1999) reported a reduction of just 42% in the ciliate population.

Microbial populations

Rumen ciliate protozoa was reduced by 64.25% and 87.67% after supplementing the sheep with 2 and 4 g/Kg LW of fruits of Sapindus saponaria (P<0.05). Several works have reported similar results of the toxic effect of saponins on rumen ciliate (Diaz et al. 1993; Hristov et al. 1999; Valdez et al. 1986; Makkar et al. 1998; Thalib et al. 1996). However, in contrast with the findings of Newbold et al. 1997, who reported a just transient effect of saponins from Sesbania sesban on rumen protozoa, rumen population was kept low for more than 11 weeks. Previous work (not published) done at TIBAITATA by the author of this paper, found that if the source of saponins (either leaves of Enterolobium cyclocarpum or fruit of Sapindus saponaria) was removed from the diet, the population of protozoa will reach the original density in approximately 4 to 5 weeks. This observation, besides the fact that the remaining population of protozoa which apparently was not affected by the saponins do not occupy the niche of the susceptible population (i.e. do not growth to the initial density) may suggest the possibility of other effects of saponins in the rumen environment in addition to its toxicity to protozoa cells.

The trend of a larger bacterial population (statistical differences were not detected because of the high coefficient of variation) in sheep receiving saponins (Table 3) and the lower concentration of rumen ammonia in sheep receiving saponins which was similar to that found in defaunated sheep (Table 5), suggest that reduction of ciliate protozoa increased the efficiency of bacterial synthesis and the flow of bacterial nitrogen to duodenum. Defaunation have consistently increased rumen bacterial population (Leng, 1990). The present experiment contributes to show that the utilization of plant containing saponins to a level which reduced drastically the ciliate population (more tan 60%), may be an alternative to improve the efficiency of rumen to produce and export microbial protein to duodenum. Thalib et al (1996) also found that the supplementation of extract of fruits of Sapindus rarak (presumably containing tha saponin fraction) to a level of 0.07% of liveweight for a 14-weeks period, increased the bacterial population by 69%, while that of protozoa was reduced by 57%.

Table 2. Rumen ciliate protozoa density of sheep fed on a wheat straw basal diet without and with supplementation of fruits of Michu (Sapindus saponaria) at 2 and 4 g/Kg Liveweight



Entodiniomophs

Holotrichs

Total

Cells (x105/ml)

% of total

Cells (x105/ml)

% of total

Cells (x105/ml)

MICHU-4

0.61c

89.31

0.073a

10.69

0.683c

MICHU-2

1.91ª

96.46

0.074a

3.54

1.980a

CONTROL

5.41b

97.65

0.143b

2.35

5.540b

Values in the same column with different subscripts differ significantly (P<0.05).

Table 3. Fungal and cellulolytic bacterial population in sheep fed on a wheat straw basal with and without supplementation of fruits of Michu (Sapindus saponaria)


Animal

Esporangia/mm2

Cellulolytic bacteria (UFC/ml)

CONTROL

4805

52

0.86

4811

18

0.16

4815

31

1.66

4879

50


MICHU-2

4839

5

496.4

4809

21

32.40

4829

10

25.00

4855

5


Rumen environment and cell wall digestibility

Fauna status did not affect effective degradability of wheat straw cell wall (Table 4). The apparent reduction of the population of rumen fungi (Table 3.) may have reduced hemicellulose digestibility (Lee and Cheng, 2000). However, the increase in bacterial population could have far counteracted this reduction (Dehority and Tirabasso, 2000), being the overall effect a higher cell wall digestibility. Rumen pH, on the other hand, was more suitable for fibrolytic activity in sheep receiving the low level of saponins. The lowest pH in this group was 6.15 at 10 hours after feeding (data not shown), while in the CONTROL group the lowest pH was was 5.9 at 10 and 14 hours after feeding. We found that saponin pKa was 6.5, which make it them a weak acid and therefore would eventually help to buffer the rumen contents when pH falls below this point.

Table 4. Effective degradability of wheat straw cell wall (FDN) in defaunated, ciliate population reduced (MICHU-2) and normal fauna sheep fed on a wheat straw basal diet.



Dilution Rate for solid fraction* (%/h)

4%

5%

6%

CONTROL

24.15

21.55

19.68

MICHU-2

23.00

20.67

18.93

DEFAUNATED

25.70

22.95

21.00

* Values assumed

Klita et al (1996) found a dose-response figure of saponin supplementation on rumen motility. A ruminal infusion of 1.6 g/Kg of saponin extract from alfalfa reduced drastically the frequency and level of rumen contractions. However when the extract infusion was half the initial dose (i.e. 0.8g/Kg liveweight) there was a much lower effect and just for 30 minutes after inoculation. In the present experiment the level of saponin (0.72g/Kg liveweght) did not affect liquid fraction dilution rate (Table 5). It is important however to mention that we found a much more drastic effect of saponins on animal metabolism when they were infused into the rumen rather than offered in the diet. A severe liver tissue damage was observed when the dose of 4gMichu/Kg of liveweight was infused through the cannula.

Table 5. Rumen ammonia nitrogen concentration, rumen volume and dilution rate in defaunated, ciliate population reduced (MICHU-2) and normal fauna sheep fed on a wheat straw basal diet.


NH3
(mg/100 ml rumen fluid)

Rumen Volume
(Lts)

Dilution rate
(%/h)

CONTROL

48.21a

20.70

5.21

MICHU-2

37.03b

24.21

3.83

DEFAUNATED

35.55b

21.89

4.66

Values in the same column with different subscripts differ significantly (P<0.05).

Conclusions

Supplementation of ruminants with saponins from fruits or tree leaves it is suggested as alternative to increase the flow of microbial protein from the rumen to duodenum and thereby to improve grazing ruminant productivity. However to do so, the amount of saponin required to be consumed seems to be much higher than the amount an animal may eat from fresh leaves and fruits. Therefore, saponins have to be concentrated and offered within a supplement.

References

BINNERTS, W.T., A. Klooster and A. Ferns. 1962. Soluble chromium indicator measured by atomic absorption in degistion experiments. Veterinary Record. 82:470-476.

CECAVA, M.J., L.C. Merchen, L.C. Gay and L.L. Berger. 1990. Composition of ruminal bacteria harvested from steers as influenced by dietary energy level, feeding frequency and isolation techniques. Journañ of Dairy Science. 73:2480-2488.

COLEMAN, G.S. 1989. Protozoal-bacterial interactions in the rumen. In: The roles of protozoa and fungi in ruminant digestion. Editors J.V. Nolan, R.A. Leng and D.I. Demeyer. Armidale, Australia. pp:13-28.

DEHORITY, B.A. 1984. Evaluation of subsampling and fixation procedures for counting rumen protozoa. Applied and Enviromental Microbiology. 48:182-185.

DEHORITY, B. and Patricia Tirabasso. 2000. Antibiosis between ruminal bacteria and ruminal fungi. Applied and Enviromental Microbiology. 66:2921-2927.

DIAZ, Aracelis, M.A. Avendaño and A. Escobar. 1993. Evaluation of Sapindus saponaria as a defaunating agent and its effect and its effect on different ruminal digestión parameters. Livestock Research for Rural Development. 5:1-6. DIAZ, Aracelis, M.A. Avendaño and A. Escobar. 1993. Evaluation of Sapindus saponaria as a defaunating agent and its effect and its effect on different ruminal digestión parameters. Livestock Research for Rural Development. 5:1-6.

HRISTOV, A., A. Mc Allister, F. Van Herk, K.J. Cheng, J. Newbold and P. Cheeke. 1999. Effect of Yucca shidigera on ruminal fermentation and nutrient digestion in heifers. Journal of Animal Science. 77:2554-2563.

JOBLIN, K.N. 1981. solation, enumeration and maintenance of rumen anaerobic fungi in roll tubes. Applied and Environmental Microbiology. 42:119-121.

KLITA, P.T., G. Mathison, T. Fenton and R. Hardin. Effect of alfalfa root saponins on digestive function in sheep. Journal of Animal Science. 74:1144-1156.

LEE, S.S. and K.J. Cheng. 2000. Relative contributions of bacteria, protozoa and fungi to in vitro degradation of Orchard grasss cell walls and their interactions. Applied and Enviromental Microbiology. 66:3807-3813.

LENG, R. 1990. Factor affecting the utilization of poor quality forages by ruminants particularly under tropical conditions. Nutrition Research Reviews. 3:277-303.

NAVAS, A. 1992. Effect of varying the ratio of fibre to soluble sugars in the diet on rumen function and productivity of faunated and defaunated sheep. Master Thesis. The University of New England.

NAVAS, A. M.A. Laredo, Aurora Cuesta, Margarita Romero and Olga Ortega. 1994. Evaluation of tropical trees with high of medium saponin content as dietary alternative to eliminate protozoa from the rumen. In: Proceedings of the VIII International Symposium on Ruminant Physiology. Wellingen, Germany.

NOLAN, J.V. and S. Stachiw. 1979. Fermentation and nitrogen dynamics in Merino sheep given a low-quality roughage diet. Br. J. Nutr. 42:63-79.

TEFEREDEGNE. B., F. McIntosh, P.O. Osuji, A. Odenyo, R. Wallace and J. Newbold. 1999. Influence of foliage from different accesions of the sub-tropical leguminous tree, Sesbania sesban, on ruminal protozoa in Ethiopian and Scottish sheep. Animal Feed Science and Technology. 78:11-20.

HRISTOV, A., A. Mc Allister, F. Van Herk, K.J. Cheng, J. Newbold and P. Cheeke. 1999. Effect of Yucca shidigera on ruminal fermentation and nutrient digestion in heifers. Journal of Animal Science. 77:2554-2563.USHIDA, K., S. Kayouli, S. De Smet and J.P. Jouany. 1989. Effect of defaunation on protein and fibre digestion in sheep fed ammoniated treated straw with and without maize. British Journal of Nutrition. 64:765-775.

Agronomic studies performed on Morus alba in Cuba

G. Martín, F. García, F. Reyes, I. Hernández and Milagros Milera

Introduction

Mulberry is a tree or shrub traditionally used for feeding the silkworm in different countries. It belongs to the order Urticales, family Moraceae, genus Morus. The most known species, Morus alba L. and Morus nigra L.., seem to have originated at the foot of the Himalayas. As forage it shows excellent bromatological characteristics. It has contents of crude protein higher than 20% and its in vitro digestibility of dry matter is higher than 80%.

Literature reports the following climatic ranges for the cultivation of mulberry: temperature from 18 to 38 °C; rainfall between 600 and 2500 mm; photoperiod, from 9 to 13 hours/day and relative humidity between 65 and 80% (Ting - Zing, Yun - Fang, Guang - Xian, Huaizhong and Ben, 1988). Currently, its cultivation has been reported from sea level to an altitude of 4000m. It is reproduced by seeds, cuttings, layers and grafting.

The use of forage trees as feeding supplement is very important, because this resource may be produced at the farm itself. Besides, it may substitute other sources of supplementation such as concentrates; cotton, fish and bran meals; as well as bran and milling wastes, which are available at the market, but can hardly be afforded by small and medium producers.

Because of the need for finding new forages of higher feeding values than conventional ones, this work presents the results of different agronomic essays performed with M. alba in Cuba.

Experimental methodology

A pruning trial was prepared in an area with Tigreada variety already planted and a completely randomized design under the edafoclimatic conditions of the Experimental Station of Pastures and Forages “Indio Hatuey”, which is located in the municipality of Perico, Matanzas province. Two pruning heights (50 and 100 cm) and three pruning frequencies were used. Each treatment was represented by 20 plants distributed at random in the field and planted at a distance of a meter between furrows and 0.40 m between plants. They were not irrigated and two applications of poultry dung equivalent to 150 kg of N/ha/year were carried out in the prunings of the rainy season.

During a year, 8, 6 and 4 prunings were performed with the frequencies of 45, 60 and 90 days, respectively. Production of total biomass and its components (leaf, ligneous stem and soft stem) was determined for the 20 plants of every treatment; edible biomass was calculated from the components. The production of total biomass and its components was estimated by the average individual dry weight per plant and taking into account the maximum possible amount of plants in a hectare (25 000).

Another trial was performed under similar conditions of soil and climate at the EEPF “Indio Hatuey” in order to evaluate the effect of intercropping temporary legumes on the establishment of M. alba. A randomized block design with four replications was used; the size of the plot was 10 x 10m. Four treatments were studied:

M. alba
M. alba + 50 kg N
M. alba + Lablab purpureus
M. alba + Canavalia ensiformis

Tigreada variety was planted in September, 1988 with a 1 x 0.40 m frame and 25 cm - long cuttings were used; afterwards different legume species were sown between the mulberry furrows. The harvest of the legumes was carried out when the coloration of the pods changed from green to brown (harvest of L. Purpureus: January 6, 1999; harvest of C. Ensiformis: April 5, 1999) nitrogenous fertilizer was applied 60 days after sowing.

Two manual weedings were performed, and the pruning of mulberry was carried out after a year of sowing, in order to evaluate total biomass production (total DMY), as well as that of the components of edible biomass (DMYEB), height, number of branches, yield in grain and plant residues of the different legume species.

Two trials were carried out on a Ferralitic - Red compacted soil of the Polytechnic Institute “Villena Revolución”, located at Boyeros municipality, Havana City province, in order to study the effect of pruning height and frequency on biomass production and its bromatological value during the dry season, from October, 1998 to April, 1999. In order to achieve this objective, two experiments were prepared in an area that had been planted for 1.5 years. A randomized block design with four replications was used. The experimental plots in each trial had 10 plants, from which 8 were used as net experimental plot; i.e., 32 plants/treatment were evaluated individually. Total biomass, as well as the biomass of every component, was determined for each plant; and the contents of crude protein and fiber were determined in a sample of each plot. Pruning heights studied were 20, 30 and 40 cm, and pruning frequencies were 45, 60, 75 and 90 days. A pruning frequency of 90 days was used for the height trial, and the frequency trial was performed with a pruning height of 30 cm. Descriptive statistics and variance analysis were used for result interpretation in all the trials.

Results and discussion

In the analysis of the results of the pruning height and frequency trial carried out at the EEPF “Indio Hatuey”, total biomass production showed highly significant differences (P<0,001) among pruning frequencies, but not among pruning heights. There was no interaction between both factors (Table 1).

From the frequencies used, the highest biomass production was shown at 90 days 1 030,6 g DM/plant/year). It may be inferred from this result that around 25 t DM/ha/year can be produced with a plant density if 25 000 plants/ha, if each plant produces 1 kg DM/year.

Table 1. Influence of pruning height and frequency on biomass production (g DM/plant/year).

Variable/treatment

Height (cm)

SE ±

Frequency (days)

SE ±


50

100


45

60

90


Total biomass

649,9

669,9

43,9

536,5 b

513,8 b

1030,6 a

62,2 ***

Edible biomass

532,5

453,3

85,1

456,1 b

377,6 b

645,2 a

120,3 *

%

82

68


85

74

63


% Proportion of edible biomass from total biomass

Meams for frequency with same letter are not significantly

* P<0,05 *** P<0,001

Edible biomass production had the same behavior. In this case there were significant differences (P<0,05). For the 90 - day frequency, 645.2g DM/plant/year were produced, which is approximately equivalent to 16 t of edible DM/ha/year that represented 63% of total biomass. Although 45 - day and 60 - day frequencies had higher percentages of edible biomass, their production values were lower. These results are similar to those obtained in the humid tropics of Costa Rica by Benavides et al. (1994), and in the dry tropics of Guatemala by Rodríguez et al. (1994). There was a similar behavior for the components of total biomass among the pruning heights studied (50 and 100 cm), which proves that day can be manifested independently from the pruning height used.

Table 2 shows total biomass production and edible biomass production. No significant differences were found in the components among treatments A, B and C, although there was a tendency to favor treatment B (9,8 t/ha) for total yield. The lower values of edible biomass (2,5 t/ha) and total biomass (5,3 t/ha) were observed with the intercropping of C. ensiformis (D), with differed significantly (P < 0,01) from the other treatments. The reason for this could be that C. ensiformis had a very aggressive growth and covered mulberry with its branches, which prevented the passage of light. Cover crops, when inadequately managed, may act as weeds because they shade the main crop and compete for water and nutrients. This can be solved using a different agrotechnical management like pruning, spatial orientation, etc.

Table 2. Effect of intercropping legumes on mulberry yield.


DMYEB

TDMY

M. alba

3,4ª

8,5ª

M. alba + 50 kg N

3,8ª

9,8ª

M. alba + L. purpureus

3,5ª

9,4ª

Morera + C. ensiformis

2,5b

5,3b

SE ±

1,8***

3,30***

DMYEB Þ Dry matter yield edible biomass
TDMY Þ Total Dry Matter Yield
a,b Differ significantly down at P < 0,05 *** P<0,001

The results of dry matter yield during the establishment period coincide with those obtained by Martín, Yepes, Hernández and Benavides (1998) for Tigreada variety. They corroborate the performance of the plant under these experimental conditions.

By intercropping legumes with mulberrry, (Fig.1) an additional production of grains, of 0,87 and 0,92 t/ha, was obtained for L. purpureus and C. ensiformis respectively. Furthermore, crop residues were generated, which could help to maintain soil fertility by means of nutrient recycling.

Fig. 1. Yield of grains and vegetable residues of intercropped legumes

The results of this trial prove that it is possible to substitute certain quantities of the nutrients needed by mulberry with the intercropping of short-cycle herbaceous legumes, for, although there were no significant differences among treatments A, B and C, the last two ones increased total biomass production in 1,3 and 0,9 t/ha respectively, as compared to A. In addition, treatments C supplied the equivalents to 870 kg grains/ha and 350 kg of plant residues/ha; the latter were incorporated to the soil, but they were also used as feed. The works carried out at the Polytechnic Institute “Villena Revolución” showed that pruning had no effect on total biomass production or the production of its components (leaf, non-edible and edible stem).

It is important to stand out that, among biomass components, the highest yield was reached by the leaves with an approximate proportion of 55 %. If we consider that edible stem represents 12 %, it can be inferred that 67 % of total biomass is edible; i.e., around 7 t of edible DM/ha were achieved in the dry season, these results are higher than those reached with other conventional feeds under these experimental conditions. When studying the effect of pruning frequency on total biomass production and the production of its components, significant differences (P<0,05) were found. Table 3 shows that biomass production in each variable was directly proportional to pruning frequency. In all the cases, the highest values were reached with the 90-day frequency.

Table 3. Influence of pruning frequency on the yield of total biomass and its components (t DM/ha). Dry season, 1998-1999.

Variables

Pruning frecuency (days)

45

60

75

90

ES

Non-edible stem

0,06c

0,38c

1,15b

3,38a

0,263*

Edible stem

0,33b

0,41b

0,82ª

0,83a

0,087*

Leaves

2,70c

2,60c

3,79b

5,24a

0,261*

Total biomass

3,09c

3,39c

5,76b

9,45a

0,493*

a, b, c Differ significantly across at P<0,05
*P<0,05

Significant differences (P<0,05) were also found among pruning frequencies for each of the variables measured regarding the content of crude protein (Table 4). This content decreased in almost all the variables with the increase of frequency, which is explained by the increase of lignification and crude fiber.

Table 4. Influence of pruning frequency on percentage of crude protein

Variables

Pruning frequency (days)

45

60

75

90

SE

Total biomass

24,07a

16b

14,74c

15,63bc

8,28*

Leaves

26,91a

24,36b

23,62b

21,39c

0,36*

Edible stem

11,49a

10,83a

11,19a

8,94b

0,42*

Non-edible stem

-

11,77a

9,24b

7,56c

0,04*

a,b,c Differ significantly across.
* P<0,05

If DM production of total biomass in the dry season (9,45 t/ha) and its CP content (15,63 %) are analyzed, we find that it is possible to produce in this season almost 1,5 t CP/ha. These results are similar to those obtained with transgenic soybean, but in a one-year period (Preston, 1999). It means that a hectare of mulberry can almost triplicate the protein production of a hectare of transgenic soybean in a year.

Conclusions

After analyzing the results of each trial it was possible to reach the following conclusions:

Pruning heights (20, 30, 40, 50 and 100 cm) did not significantly influence the production of total dry matter or its components, and it did not significantly influence crude protein.

Pruning frequencies (45, 60, 75 and 90 days) significantly influenced the production of total biomass and its components, and the contents of crude protein. The ninety-day frequency showed the best results in the trials performed at the EEPF “Indio Hatuey” and at the Polytechnic Institute “Villena Revolución”.

The intercropping of short-cycle herbaceous legumes in mulberry establishment may contribute to the increase of biological, economical and ecological sustainability of production systems where this forage species is included.

The results of mulberry biomass production and quality, mainly in the dry season, show the potential of this plant for Cuban conditions, which indicates the need of continuing the agronomic studies approached in this work and others that are necessary to introduce mulberry in Cuban livestock exploitations.

References

Benavides, J.E.; Lachaux, M. & Fuentes, M. 1994. Efecto de la aplicación de estiércol de cabra en el suelo sobre la calidad y producción de biomasa de Morera (Morus sp.). En: Arboles y arbustos forrajeros en América Central. (Ed. J.E. Benavides). CATIE. Turrialba, Costa Rica. Vol. 2, p. 495

Martín, G.J.; Yepes, I.; Hernández, I. & Benavides, J.E. 1998 Evaluación de comportamiento de cuatro variedades de Morera (Morus alba) durante la fase de establecimiento. Memorias. III Taller Internacional Silvopastoril “Los árboles y arbustos en la ganadería”. EEPF “Indio Hatuey”. Matanzas, Cuba. p.92

Preston, T.R.1999. La Revolución Pecuaria: Recursos locales como alternativa a los cereales. Resúmenes. VI Seminario Internacional sobre Sistemas Agropecuarios Sostenibles. Coli Colombia. P.22

Rodríguez, C.; Arias, R. & Quiñones, J. 1994. Efecto de la frecuencia de poda y el nivel de fertilización nitrogenada sobre el rendimiento y calidad de biomasa de Morera (Morus sp.) en el trópico seco de Guatemala. En: Arboles y arbustos forrajeros en América Central. (Ed. J:E. Benavides).CATIE. Turrialba, Costa Rica. Vol. 1, p.305

Ting-Zing, Z.; Yung-Fang, T.; Guang-Xian, H.; Huaizhong, F.& Ben, M. 1998. Mulberry cultivation. FAO Agricultural Services Bulletin. No. 73/1. FAO, Rome. 127 p.

Nutritive value of four Atriplex species

Morfín Loyden L.[243], Medina C. H.[244], Camacho Morfín D[245].

Key words: browse, forage quality, tree fodder.

Introduction

Arid and semiarid areas occupy most of the total surface of Mexico and some places has saline soils that limit the fodder production and reforestation. Its necessary a bank of resistant species to dry and saline conditions in order to feed animals over all at dry season. Many spices of Atriplex genus have the advantage of grown in saline soils at dry season for that the aim of this study was estimated the nutritive value of four Atriplex species at the dry season, in order to have information about the characteristics of this genus and promote the fodder use in México.

Materials and methods

The study was conducted between April and May 1996 on the botanic introduction garden of the Texcoco ex Lake, Estado de México, México. The site is located at an altitude of 2353 m asl, latitude 19o 22' and 19o 37' N; longitude 98o 54' and 99o 3' W, and has an average annual rainfall of 454.6 mm. The soil is an Solonetz called either black alkali. Edible branches of Atriplex palludosa, Atriplex halimus, Atriplex canescens and Atriplex acanthocarpa were collected at the dry season, between April and May, from the Texcoco ex Lake introduction garden; samples consisted of branches less than 10 mm of diameter, they were separated on branches, leaves and stems, that subsamples were oven dried at 50 oC for 48 h and and milled to passthrough a 1 mm aperture. Crude protein, ash and calcium were completed as described by AOAC (1990), neutral detergent fiber (NDF) were determined according Goering and van Soest (1970). Organic matter in vitro digestibility by Tilley and Terry (1960). Data were subjected to analysis of variance (ANOVA) and the differences between the means were separated using the least significant difference methods of Steele and Torrie (1985).

Results and discussion

Branches longitude, chemical composition and digestibility of branches, leaves and stems of the four Atriplex spices are shown in Table 1. A. halimus showing the highest branches longitude, that browse has longer edibles branches than the others spices. There were wide variations between chemical components of branches, leaves and stems; the last one showing the lowest crude protein content, less than 8 %. Composition of such plants are similar to others reports (Holechek et al., 1990; Kaitho, 1997). Generally, there were highest crude protein and lowest NDF in leaves than stems, like others spices. Stems's OMIVD was highest than leaves, data suggest that stems NDF has low lignin contents. Calcium contents were varied between species, but the highest contents were those of the A. palludosa. This kind of behavior is similar to many green fodder.

Table 1. Chemical composition of branches, leaves and stems of four Atriplex species.

Spices

Longitude1
cm

Crude protein
%

Ash
%

NDF
%

Calcium
%

OMIVD2
%

Atriplex acanthocarpa








Branches

31.55 b3

10.05 e

22.44 d

55.10 e

0.53 fg

53.77 i


Leaves


15.90 a

15.44 h

63.56 b

0.68 c

33.58 k


Stems


8.18 g

19.59 e

63.49 b

0.60 e

34.61 j

Atriplex canescens








Branches

28.59 b

9.47 f

16.42 g

49.17 g

0.64 d

74.20 e


Leaves


14.90 b

30.28 a

29.90 k

0.51 g

76.86 d


Stems


7.15 h

26.13 b

45 h

0.54 f

84.81 a

Atriplex halimus








Branches

54.6 a

10.29 e

13.10 i

53.48 f

0.47 h

76.84 d


Leaves


14.13 c

15.14 h

38.55 i

0.45 i

78.97 c


Stems


7.95 g

16.23 g

60.17 d

0.51 fg

83.12 b

Atriplex palludosa








Branches

30 b

12.25 d

17.04 f

62.03 c

0.7 b

56.34 g


Leaves


12.81 d

24.29 c

30.69 j

0.69 bc

60.03 f


Stems


4.41 i

4.05 j

74.35 a

0.77 a

54.34 h

1= branches longitude; 2= Organic matter in vitro digestibility; 3= Means with common letters in columns are not significantly different (p>0.05).

Conclusions

It may be concluded that the four Atriplex species have high nutritional quality, but to come off A. halimus because has highest digestibility and calcium contents.

References

A.O.A.C. Association of Official Analytical Chemists (1990) Official Methods of Analysis. 15 th ed. Association of Official Analytical Chemists. Washington D.C. USA. pp.69-88

Goering K. and van Soest P.J (1970) Forage fibre analysis: Apparatus, reagents, procedures and some applications. Agric. Handbook 379. 1-20.

Holechek J.L., Munshikpu A.V., Saiwana L., Nunez-Hernandez G., Valdez R., Wallace J.D. and Cardenas M. (1990) Influences of six shrub diets varing in phenol content on intake and nitrogen retention by goats. Tropical Grasslands. 24:93-98.

Kaitho R.J. (1997) Nutritive value of browses as protein supplement(s) to poor quality roughages.Thesis Landbouw Universiteit Wageninge. The Netherlands. pp. 82

Steele G R D and Torrie H J (1985) Bioestadística: Principios y Procedimientos. Martínez R.B. (trad.).McGraw-Hill. Bogotá, Colombia. 622 p.

Nutritional characteristics of forage species in the silvipastures of multiple strata in Chiapas, Mexico

René Pinto-Ruiz[246], Luis Ramírez-Avilés[247] y Juán.Carlos Ku-Vera[248].

Key words: forage trees, herbaceous plants, ruminants, tropics

Introduction

Recently, the silvipasture system investigations have assumed a more important paper due to the necessity of productive design systems that are in harmony with the enviroment. Under this context, cattle improvement with the use of wood and herbaceous plants associated with pastures is a strategy that should be exploited, especialy in world tropics, due to its great vegetable biodiversities. In this respect, in the central valley of Chiapas, Mexico, exists a wide empirical knowledge in the producers as to the great diversity of vegetable forage species; but they know little of their nutritional quality. This apparent situation the potential of the region to develop efficient strategies for animal production, but this great diversity has not been tested in a systematic form. For this it is neccesary to recognize amd to generate bigger knowledge in this respect.

For the above mencioned, the object of this study was to characterize the chemical composition and the degration values of ruminants “in situ” of the vegetable species of more forage use integrant of the diverse strata in silvipasture systems of the south of Mexico.

Materials and methods

Characteristics of the study area

The study was done in the central valley in the state of Chiapas, which possesses a longitude of 280 km and a width of 32.5 km; the altitude average is of 575 m.a.s.l.; with annual average rainfall and temperature of 1,100 mm and 25.5 oC, respectively. The predominat climates are: warm subhumid with rains in summer, partly warm humid with rains in summer and partly warm subhumid with rains all year round. The soli is classified as Cambisoles, Rendzinas and Luvisoles (García, 1988; Nieuwkoop et al., 1994).

Sample colletion

The selection of the species considered in the study was based on the local knowledge of its use forage for bovine (Pinto et al., 2000). They were obtained by means of transects found in all the municipalities of the study zone, collecting as minimun 25 samples of each species using for it grazing simulation (Fick et al., 1979). Tender leaf or stems and/or fruits were used.

Chemical-nutritional composition

The samples were analized to determine the Crude Protein content (CP) and Organic material (OM) (A.O.A.C., 1990), the fractions of Neutral Detergent Fiber (NDF) and Acid Detergent Fibre (ADF) were determined as described by Vant Soest et al. (1991) and the presence of Total Phenols (TP) according to the techniique of Domínguez (1979).

Ruminal degradability

Four Zebu-Brown Swiss young bulls were provined using flexible ruminat cannulas. The bull´s feed was bassed on stargrass (Cynodon mlenfuensis). The degradations of the tree foliage were carried in the dry season and the herbaceous plants during the wet season with the purpose of creating a similar ruminal selling condition and according to the time of consumption of these species by the animals. To measure the ruminal degradation of the Dry Matter (DDM), Organic Matter (DOM) and the Crude Protein (DCP), the nylon bag technique was used (Orskov et al., 1980). The bags were introduced for duplicated to each animal during the incubation period (24 hours). The disappearance of the DM, OM and CP were expressed in percentage and estimated by differences among the existent quantity of the incubated material less the quantity of the residual material.

Statistical analysis

The analysis of variance was done for the degradability “in sacco” at 24 hours of the DM, OM and CP among the species studied as the main factor used en the process using the General Procedure to Lineal Model. The comparation between means were done with the multiple range test of Turkey. Both analyses were carried with the statistical package SAS (SAS, 1994).

Results

The tables 1,2 and 3 show the results of the chemical analysis and ruminal degradability of the seleccted species. The content of CP varied of half to high (5.8-28.7%), being prominent the herbaceous species. The content of OM was very similar between species (79.1-96.6%), the highest levels of NDF and ADF were found in the fruits and the largest concentrations of TF were found in the leaves of the woody species, being prominent B. ungulata (4.2 g/100 g). Contrarily to what was expected, the herbaceous species presented the smallest concentrations of TF. On the other hand, the foliage of G. sepium, P. dulce, G. americana, D. robinioides, L. leucocephala and E. goldmanii, and the fruit of E. ciclocarpum as well as all the herbaceous species presented the highest values at 50% of disappearance ruminal of the DM, OM and CP; being prominent in these, the foliage value of G. americana and the fruit of E. cyclocarpum (P<0.05), while the foliage and fruit of A. pennatula and the foliage of B. ungulata and M. hondurana presented the lowest values of all the species in the evaluation (P<0.05).

Table 1. Chemical composition and ruminal degradation (%) of the foliage of trees and bushes of more forage use in the central valley of Chiapas, Mexico.

Scientific name

CP

OM

NDF

ADF

TF

DDM

DCP

DOM

Guazuma ulmifolia

10.4

86.2

42.5

29.5

2.8

40.87 f

19.03ef

40.88ed

Gliricidia sepium

23.8

89.4

38.5

24.7

0.3

67.25 b

74.85ª

63.38b

Acacia milleriana

11.8

91.5

42.7

28.5

3.5

46.90 e

28.26de

44.15d

Acacia pennatula

12.5

92.9

59.0

35.8

2.8

28.94 g

12.13f

28.04f

Pithecellobium dulce

19.6

89.9

45.2

29.3

0.6

59.83 cd

65.26b

61.70bc

Genipa americana

9.4

91.5

37.7

30.9

0.9

77.26 ª

69.06ab

76.87ª

Diphysa robinioides

18.7

88.2

31.7

23.2

0.6

61.27 c

70.56ab

60.78bc

Leucaena leucocephala

20.1

89.8

27.5

19.1

0.3

54.37 d

45.58c

46.33d

Erythrina goldmanii

22.8

88.0

43.1

28.8

0.6

57.83 cd

62.22b

54.71c

Acacia farnesiana

24.0

92.2

42.1

26.7

1.0

41.74 ef

45.90c

39.64de

Bauhinia ungulata

13.2

92.8

42.4

26.5

4.2

34.14 g

20.24ef

34.30ef

Albizzia caribaea

16.6

94.3

36.7

31.0

0.9

46.51 ef

35.53d

44.81d

PC: Crude Protein; OM: Organic Matter; NDF: Neutral Detergent Fiber; ADF: Acido Detergent Fiber; TF.: Total Phenols; DDM: Dry Matter Degradability; DCP: Crude Protein Degradability; DOM: Organic Matter Degradability.

Means with different superscripts within a column are significantly different (P<0.05)

Table 2. Chemical composition and ruminal degradation (%) of the fruits of trees of more forage use in the central valley of Chiapas, Mexico.

Scientific name

CP

OM

NDF

ADF

TF

DDM

DCP

DOM

Leucaena leucocephala

18.6

94.2

51.9

37.0

1.3

44.81 c

65.53b

44.39b

Guazuma ulmifolia

5.8

94.7

46.1

35.4

0.6

49.82 b

43.42e

44.71b

Acacia pennatula

8.5

95.5

72.0

48.7

2.0

22.87 e

52.16d

20.94d

Enterolobium cyclocarpum

16.43

96.69

33.9

22.15

0.14

65.41a

86.98a

65.15a

Ficus glabrata

15.8

90.2

64.4

49.8

0.02

34.22d

39.05e

33.78c

Acacia milleriana

8.1

94.9

52.3

37.2

2.6

33.40 d

57.33c

32.46c

Means with different superscripts within a column are significantly different (P<0.05)

Table 3. Chemical composition and ruminal degradation (%) of the herbaceous species of more forage use in the central valley of Chiapas, Mexico.

Scientific name

CP

OM

ADF

TF

DDM

DCP

DOM

Ipomoea triloba

21.9

84.6

21.7

0.3

77.62 ab

85.14a

79.56b

Stizolobium deeringianum

34.0

89.1

16.9

0.2

82.97b

94.74b

87.36b

Stizolobium pruriens

22.9

91.1

25.7

0.6

68.54a

84.68a

66.12ª

Sanvitalia procumbens

28.7

83.1

16.1

0.3

87.27 ª

92.59ª

87.60a

Amaranthus hybridus

27.6

79.1

14.1

0.1

80.49 b

78.57b

82.82ª

Sida acuta

25.2

88.3

15.6

0.3

85.90 ab

90.30a

82.63a

Mimosa hondurana

17.8

93.5

24.6

1.1

51.28 c

52.21c

52.16b

Means with different superscripts within a column are significantly different (P<0.05)

Discussion

None of the estimates in chemical composition or in degradability found in this study had a great difference in the diverse values published for the considered species. Taking into account the nutritional aspect, the fact that some species presented an acceptable quantity of CP, moderate levels of Fiber fractions, a low content of antinutritional factors and that it be accepted by the animals, makes the use of these species in the cattle raising to be promissory (Febles, 1995). The CP and the DCP are important indicators of the nutritional quality of forage species, for this the reported values for many of the species here evaluated are sufficient to consider as protein suplements in pastures of low quality (El hassan et al., 2000). Since they found superior values of CP in some cases up to 100% concerning the content of tropical grasses.

All the wood species, especially their fruit, contained significant contents of NDF and ADF, which indicates a lower content of soluble matter available for the animals, being prominent the fruit of A. pennatula (NDF=72.2 and ADF=48.0%). On the other hand, the foliage of G. utmifolia, B. ungulata and the foliage and fruit of A. milleriana and A. pennatula possess important contents of TF. Of this it can be appreciated the high levels of fiber fractions and of TF, it appearently are associated with the low values of ruminal degradability at 24 hours of the DM, OM and CP that present (<50%). With relationship to the herbaceous species, the CP values are superior to many trees species and especially to that of tropical pastures. The cellular wall values in general are very low, this permits the high percentages of ruminal degradation which could guarantee an important supply of nutrients to the animal diet when this selects them..

Conclusion

In general, the woody and herbaceous species studied presented acceptable levels of CP, OM, fiber frations, low content of TF and values means of DDM, DOM and DCP, which shows the nutritional potencial of many of them and that its inclusion in diets of poor quality could improve the efficency of the use of these, therefore the promotion of the employment of these species in multi-strata systems is justified.

References

A.O.A.C. 1990. Official Methods of Analysis of the Association of Official Analytical Chemists. 15 th ed. Washington, D.C. U.S.A.

Domínguez. G. 1979. Métodos Fitoquímicos para Laboratorio. 1ª ed. Ed. LIMUSA. México D.F. 213 p.

El hassan, S.M., Lahlou, A.K., Newbold, C.J., and Wallace, R.J. 2000. Chemical composition and degradation characteristics of foliage of some African multipurpose trees. Anim. Feed Sci. And Technology. 86:27-37.

Febles, G., Ruiz, T.E. y Simón, L. 1995. Consideraciones acerca de la integración de los sistemas silvopastoriles a la ganaderìa tropical y subtropical. Memoria del seminario científico internacional. Instituto de Ciencia Animal. La Habana, Cuba. p. 55-63.

Fick,, K.R.; McDowell, L.R., Miles, P.H., Wilkinson, N.S., Funk, J.P., Conrad, J.H. y Valdivia, R. 1979. Métodos de análisis de minerales para tejidos de plantas y animales. Anim. Sci. Department. Univ. de Florida. USA.

García, E. 1989. Modificación del sistema de clasificación climática de Kopen. 5ª. ed. Instituto de Geografía. Universidad Nacional Autónoma de México. México D.F. 33 pp.

Nieuwkoop, M.N.; López, W., Zamarripa, A., De la Piedra, R., Cruz, F.J., Camas, R. y López, J. 1994. Uso y Conservación de los recursos naturales en la frailesca, Chiapas: un diagnóstico. CIMMyT, México, D.F. p. 9.

Orskov, E.R., Hovell, F.D. Deb and Mould, I. 1980. The use of the nylon bag technique for the evaluation of feedstuffs. Tropical Animal Production. 5: 195-213.

Pinto, R.,.Ramìrez, L., Ku, J.C., Rodrìguez, S., Barrientos, M. y Gómez, H. 2000. Arboles, Arvenses y Enredaderas de uso forrajero en el silvopastoreo del centro de Chiapas, México. IV Taller internacional Silvopastoril Los àrboles y arbustos en la ganaderìa tropical. 1:157.159.

SAS. 1994. User's guide. 4th ed. Statistical Analysis System Institute. Inc. North Carolina. USA.

Vant Soest, P.J., Robertson, J.D., Lewis, B.A. 1991. Methods for dietary fibre, neutral detergent fibre and non-starch polysaccharides in relation to animals nutrition. J.Dairy Sci. 74: 3583-3597.

The use of Gliricidia sepium in the supplementary feeding of crossbred female calves

Decio González-Villalobos[249], Roberto Palomares-Naveda[250], Edward Navarro,
Rosa Razz[251], Gustavo Soto-Castillo[252] y Armando Quintero-Moreno[253].

Key words: bovine, food, forage, growing, tropic,

Introduction

In recent years, it has been established that bovine production must make use of grazing animals, since these represent the most abundant and economic resource to which producers in developing countries have access. In this sense, the incorporation of leguminous plants as a supplement, whether by themselves or accompanied with other fodder resource, constitutes an alternative means of attaining production increases for grazing animals in bovine breeding units. The need to generate cost-reducing alternatives to feeding has fostered the study of leguminous shrubs in order that these be incorporated into bovine feeding systems, as is the case with Gliricidia sepium, which is a species native to Mexico, Central America, Colombia, Guyana and Venezuela, where it is known as ‘matarratón’ (mouse killer), and it is widely distributed throughout a great variety of terrain (very dry tropical forest, dry tropical, humid and pre-mountainous humid) in our national geography (Chacón, 1993). This leguminous plant presents nutrient levels that are superior to critical levels required by ruminants, and is comparable to leguminous shrubs considered as having high fodder quality (Clavero, 1993; Escobar, 1996). A good example of this being the content of crude protein in its leaves, which varies between 20% and 30% and that of the stem, which varies between 13.3% and 20%, with both high energy and good digestibility (Clavero 1993). Additionally, it is a resource that can be mechanically harvested, with production levels of up to 150 metrical tons/hectare/year (Adejumo, 1991).

Gliricidia sepium is a leguminous shrub with great potential, and its introduction could represent an alternative means of minimizing nutritional deficiencies that are presented by young animals, still in the process of growth, during periods of fodder scarcity: in this sense, it was considered necessary to evaluate growth (partial and final body weight and average daily gain) of predominantly Holstein crossbreed heifers fed via two supplementation sources under the same grazing management by the farm.

The trial was carried out on the San Pedro farm, pertaining to the Faculty of Veterinary Science, University of Zulia. The farm is situated in the municipality of Machiques (Perijá), in the State of Zulia, Venezuela. The environmental characteristics of the area have been described by Quintero et al. (1997) in previous trial.

Fourteen (14) Holstein crossbreed female calves, weaned and at five months of age, were used for the trial, and were grouped into two 7-female calves groups and these groups were randomly assigned one of two treatments:

The GS flour was obtained by sun-drying (72 hours) the plant’s leaves; these were taken from plants in the same terrain area that contained branches with new shoots older than 150 days’ growth (5 months), collected during the dry season. The cornmeal and feed concentrate were acquired in a distribution outlet close to the farm, stocked by a prestigious company.

Throughout the whole day, the heifers grazed in fields of Brachiaria brizantha, and were fed the supplementation on a daily basis via a morning ration (7-9 a.m.). The amount of supplement provided for each treatment varied in accordance with 2% of live body weight. Live body weight was determined individually, using a ranch steelyard with a capacity of 1,500 kg and a precision of 1 kg. Feed was provided daily to the heifers in collective feeding stables, and evaluation of consumption was measured by assessing the difference between the weight of feed supplied voluntarily to each trough and the weight of remaining feed taken away each day. Readjustment of the amount of supplement provided was carried out every 14 days. In the same way, samples of feed concentrate, ‘mouse killer’ flour, cornmeal and mixture were taken every two weeks for a proximal analysis sequence (table 1), in order to verify its nutritional composition throughout the trial; pasture samples were taken using the technique of simulated pasture.

Table 1. Proximal analysis sequence of the rations and certain forages used in this trial.

Ration/Feed

DM (%)

CP (%)

EE (%)

CF (%)

NFE (%)

TDN (%)

AS (%)

TA

88.17

15.64

6.61

10.94

57.33

74.03

9.48

TR

82.53

19.55

1.38

21.73

48.87

71.78

8.47

GS

90.53

22.7

2.20

20.81

43.66

70.26

10.63

TA: Supplementation provided through a commercial concentrate, TR: 60% cornmeal + 40% GS flour + 50 g/animal/day of complete mineral mixture, GS: Gliricidia sepium plant, DM: dry matter, CP: crude protein, EE: ether extract, CF: crude fiber. NFE: nitrogen free extract, TDN: total digestible nutrient, AS: ashes.

The experimental design corresponds to an entirely random analysis, the feeding ration being the independent variable for evaluation. A variance-covariance analysis was undertaken by use of the minimum squares method, including trial-initial weight as a continuous variable. As dependent variables, partial and final body weight (BW) and average daily gain (ADG) were studied. Data was analyzed through the General Lineal Model (GLM) procedure in the SAS statistics package (SAS, 1996) and for the subsequent detection of significant differences between treatments undertaken, the PDIF test was used to compare square averages.

Results

Table 2, illustrates the results obtained in which it can be observed that the experimental units supplemented with TA demonstrate greater BW and ADG than those heifers that were fed on TR 14 days after having initiated the trial (P<0.01); which was due to the lower feed intake in TR (table 3).

Table 2. The effect of supplementation type on BW and ADG.

Parameter

Treatment

TA

TR

Number of female calves

7

7

Weight at start of trial (kg.)

86.28±1.05 a

87.00±1.10 a

Weight at 14 days (kg.)

93.93±1.19 a

91.49±1.19 a

Weight at 28 days (kg.)

101.91±1.77 a

93.65±1.77 b

Weight at 42 days (kg.)

104.89±2.34 a

94.52±2.34 b

Final weight (kg.)

106.65±2.51 a

96.06±2.51 b

Daily weight gain (g/d.)

334.61±42.0 a

157.0±42.0 b

(a, b): Different letters within the same row imply statistically significant differences (P<0.01)

Table 3. Feed offered (FO) and feed intake (FI) during the experiment.

Trial period
(Days)

Treatment

TA

TR

FO (kg.)

FI (kg.)

FO (kg.)

FI (kg.)

0-14

1.74

1.74

1.73

1.49

14-28

1.89

1.89

1.82

0.97

28-42

2.04

2.04

1.86

1.59

42-56

2.10

1.80

1.88

1.08

Discussion and Conclusions

It should be emphasized that the BW and ADG reported for the TR group are very low, which may be attributable to the age of the plants used (20 weeks); this considerably affects consumption. It is also possible that the GS flour presents substantial quantities of certain anti-nutritional compounds, such as tannins, which (though not determined in this experiment) are widely known as bitter substances that diminish food consumption, as occurred in this trial. Research using calves of between 113 kg and 155 kg body weight, grazing on Cynodon plectostachyus + minerals + GS mention ADG for calves varying between 360 to 650 g/d (Chacón, 1993); whilst Arredondo and Combellas (1991) indicate post-weaning moderate weight gain for calves (360-400 g/d) in critical periods with the use of GS + multi-nutritional blocks. Espinosa et al. (1993) that response to grazing restricted to banks of GS is very low (50-60 g/d). On the other hand, Seijas and Combellas (1992) suggest that better response from animals supplemented by GS is related to improved factors associated with leguminous plants, such as the slow release of degradable nitrogen, and of peptides and amino acids to the rumen, as well as the greater digestibility in relation to staple feed. Kass et. al.(1993) indicated that the ruminants without prior experience have less feed intake of GS legume plant, and Escobar et. al. (1996) said that the suitable levels for addition in the ration are between 20 and 40%, therefore we suggest preparing a ration with a minor proportion of GS flour and adding edible molasses to improve the palatability.

References

Adejumo, J. O. (1991). Effect of length and girth of vegetative planting material upon forage yield and quality of Gliricidia sepium. Trop. Agric. (Trinidad) Vol. 68 N°1: 63-65.

Arredondo, B. and Combellas, J. (1991). Influencia de la Gliricidia sepium y de los bloques multinutricionales sobre las ganancias de peso en becerros postdestete a pastoreo. In: Suplementación con leguminosas arbustivas. Informe anual 90-91. Instituto de Producción Animal (IPA). Facultad de Agronomía. Universidad Central de Venezuela, pp. 82-83.

Clavero, C. T. (1993). Las leguminosas arbóreas: una alternativa de forraje para la cuenca del lago de Maracaibo. I. Caso estudio de Gliricidia sepium. In: III Curso sobre Producción en Pastos y Forrajes. Maracaibo-Venezuela. 19p.

Chacón, C. (1993). Utilización de matarratón (Gliricidia sepium) en la alimentación bovina. IX Cursillo sobre bovinos de carne. Facultad de Ciencias Veterinarias, Maracay-Venezuela, pp. 157-176.

Escobar, A., Romero, E. and Ojeda, A. (1996). El matarratón (Gliricidia Sepium) un árbol multipropósito. Serie de Cuadernos Técnicos de la Fundación Polar. Caracas- Venezuela. 71p.

Espinosa, M., Callers, A., Gabaldon, L., Escobar, A. y Combellas, J. (1993). Influencia de la frecuencia de pastoreo restringido de Gliricidia sepium sobre las ganancias de peso de becerros postdestete. Informe anual 92-93 del Instituto de Producción Animal (IPA). Facultad de Agronomía. Universidad Central de Venezuela, pp. 36-37.

Kass, M., Pezo, D., Romero, F. and Benavides, J. (1993). Las leguminosas como suplemento proteico para animales. In: I Simposio sobre leguminosas forrajeras arbóreas. Facultad de Agronomía, Universidad del Zulia, Maracaibo-Venezuela. 17p.

Quintero-Moreno, A., Rojas, N., Aranguren, J., Soto, G. y Durán, D. (1997). Efecto de la suplementación y la época de nacimiento sobre el crecimiento predestete de becerras mestizas. Revista Científica, FCV-LUZ, Vol. VII, N°2: 75-82.

SAS (1996). SAS/STAT Software: Changes and Enhancements through Release 6.11. SAS Inst. Inc. Cary, NC.

Seijas, J. Y Combellas, J. (1992). Influencia de la harina de pescado y el follaje de Gliricidia sepium sobre las ganancias de peso en becerros postdestete. VII Congreso Venezolano de Zootecnia. Resúmenes. Universidad de Oriente. Maturín-Venezuela. NR-38.

Utilisation of the shrub Cratylia argentea CV. Veraniega as protein supplement for milking cows during the dry season in Costa Rica

Jesús González, Marco V. Lobo Di Palma, Vidal Acuña R., Pedro J. Argel, Caralos Hidalgo A. and Francisco Romero[254]

Key words: dry matter, silage, supplementation

Introduction

In areas of Costa Rica with a dry season of 5 - 6 months, farmers face serious problems supplying good quality feed to milking cows during that part of the year. Sugar cane is a suitable high energy feed but needs a protein source, such as a concentrate to make an adequate animal diet. However, concentrates are basically made with imported inputs, have a high price and are difficult to obtain by small farmers.

Forage legumes can provide adequate protein and replace partially or totally the use of costly concentrates, but most of them defoliate during the dry season and offer little feed at that period. Cratylia argentea is a shrub collected in the seasonally dry savannas of Brazil in 1984-88 and evaluated since 1988 in Costa Rica and other parts of the Latin American tropics (Argel y Lascano, 1998). It has performed well in acid infertile soils below 1200 masl, it retains a high proportion of foliage during the dry season and re-growths very well after cutting. Cultivar Veraniega is a physical blend formed by the accessions CIAT 18668 and CIAT 18516, which have similar soil adaptation and growth habit, and similar contents of Ca, P, CP and IVDMD (Shultze-Kraft, 1996).

Dry matter yields and response to cutting

Cultivar Veraniega re-grows well after cutting even during the dry season, and up to 40% of the total yield (leaves + fine stems) have been recorded during the dry period (Argel, 1995). Plants can be first cut 4 to 6 months after planting without affecting subsequent persistence; however, yields per unit area increased to a plant density of at least 20,000 plants/ha, which is a plant spacing of 1.0 m x 0.5 m in a subhumid environment (5-6 months dry) with medium fertility soils (Table 1). Individual plants yielded more both as plant age and plant spacing increased.

Table 1. Effect of plant density and age at first cut on DM yields of C. argentea (CIAT 18516) cut every 60 days at 70 cm height, Costa Rica (P. Argel, unpublished data).

Density

Plant age at first cut (months)

Means Estimated Yield

4

6

8

(plants/ha)

(kg/plant)


(t/ha)

20,000

0.158

0.149

0.238

0.182

3.6 a

10,000

0.281

0.249

0.226

0.252

2.5 b

6,667

0.335

0.359

0.357

0.350

2.3 c

Means

0.258 a

0.252 a

0.274 a



P < 0.05

Cutting trials have shown that yields are also related to plant cutting height and re-growth age. Increasing the cutting height from 30 cm to 90 cm and the age to harvest the re-growth from 60 days to 90 days, have practically doubled the DM yields (Table 2). In this trial plants had more than one year of growth when they were first cut. Crude protein decreased as plant matured, but protein contents were still within the acceptable range required for dual purpose milking cows.

Table 2. Effect of cutting height and age of re-growth on DM yields and quality of C. argentea cv. Veraniega, Costa Rica (Lobo y Acuña, 2000a).

Age of re-growth

Cutting heigth (cm)

Means Crude Protein

30

60

90

(days)

DM yields (t/ha)


(%)

60*

1.3

1.7

2.7

1.9

17.4

90**

3.9

4.6

7.4

5.3

15.3

Means

2.6

3.2

5.1



* Average of 11 cuttings.
** Average of 8 cuttings.

Silage of cv. Veraniega

Ensiling Cratylia has been a farmer-based initiative along the Central Pacific region of Costa Rica. Leaf and stem material from 3-4 months re-growth not used during the wet season, is cut fresh and mechanically chopped into 2-5 cm fine pieces. Harvested material is placed and compacted successively in 20 - 25 cm layers in heap-type silos. After good compaction has been achieved the material is covered with plastic. Adequate colour and lactic fermentation has been obtained adding 10% molasses on a dry matter basis when making silage of pure Cratylia. Similar results have been achieved adding 25% of sugar cane (dry matter basis) to fresh Cratylia, and no more than 25% of pineapple pulp (Jiménez et al., 2000). The pH of the cv. Veraniega silage has been around 4.0, and CP and IVDMD close to 15.0 and 41% respectively (Romero y González, 2000; Lobo y Acuña, 2000b). Dry matter consumption of 3.0% BW has been reported for Jersey cows feeding on a diet based on 60:40 proportions sugar cane: cv. Veraniega silage (Romero y González, 2000).

Use of cv. Veraniega as supplement for lactating cows

C. argentea cv. Veraniega has been evaluated both on-station and on-farm either with pure Jersey cows or with crossbred animals. Farmers were first offering the shrub fresh to supplement sugar cane, but then they experimented producing silage as there was no need for Cratylia in the wet season since sufficient good quality feed from pastures was available. The aim of the experiments was to reduce supplementation costs during the prolonged dry period.

Experiments carried out at the Escuela Centroamericana de Ganadería (ECAG)(460 masl, annual mean temperature of 23.7 °C, mean precipitation of 1600 mm), and in one farm located in the Central Pacific subhumid coast region of Costa Rica. At the first site six mature Jersey cows (50 days postpartum) were randomly assigned to the following treatments in a 3 x 3 crossover Latin square design: T1=sugarcane (1.0% BW) + rice polishing (0.5% BW) + concentrate (1.48% BW) + urea (0.02% BW); T2=sugarcane (1.3% BW) +concentrate (0.5% BW) +freshly cut cv. Veraniega (1.2% BW); T3=sugarcane (0.1% BW) +concentrate (0.5% BW) +silage of cv. Veraniega (2.4% BW). Each treatment period consisted of 12 days of which 7 were for adaptation and 5 for measurements. Results shown in Table 3 indicate that there was no difference (P>0.27) in milk yield of cows supplemented with concentrate and those supplemented with cv. Veraniega fresh or ensiled. However, milk protein concentration was significantly high (P<0.01) in cows fed with concentrate, meanwhile fat milk had a tendency of higher concentration in cows fed with silage of cv. Veraniega.

Table 3. Milk production, milk quality and cost of supplement of Jersey cows fed with different diets (Romero y Gonzalez, 2000).

Treatments

Milk (kg/cow/day)

Fat (%)

Protein (%)

TS* (%)

Cost of diet (US$/kg) **

Net income (US$/cow/day)

T1. Concentrate

11.1

3.53

3.36

12.39

0.21

0.84

T2. Cratylia fresh

10.9

3.69

3.24

12.47

0.17

1.26

T3.Silage of Cratylia

10.7

3.81

3.22

12.49

0.18

1.16

Sig. Difference

Ns

Ns

P<0.01

Ns



* TS, total solids.
** 1US$ = 330 colones.

At the farm level, six crossbred Brown Swiss x Brahman dual purpose cows in the third month of lactation were assigned to the following treatments arranged in a 3 x 3 cross/over Latin Square design: T1=12 kg sugar cane + 6 kg cv. Veraniega silage + 0.6 kg rice polishing; T2=12 kg sugar cane + 6 kg cv. Veraniega fresh + 0.6 kg rice polishing; T3=12 kg sugarcane +3.0 kg chicken manure + 0.6 kg rice polishing.

In this experiment there was little difference in milk yield of cows supplemented with the different diets, although a significant tendency of more milk (P<0.07) when cows were fed with cv. Veraniega fresh (Table 4). The results corroborate higher milk fat when the diet was based on Cratylia silage.

Table 4. Milk yield, milk quality and cost of supplement of dual purpose cows fed with cv. Veraniega fresh or as silage and chicken manure (Lobo and Acuña, 2000b).

Treatments

Milk (kg/cow/day)

TS

(%)

Fat

(%)

Cost of Diet

(US$/kg)**

Benefit to Cost ratio

T1. Cratylia as silage

5.1 b*

12.3

3.6

0.17

1.58

T2. Fresh Cratylia

5.5 a

12.2

3.4

0.11

2.37

T3. Chicken manure

5.3 ab

11.7

3.0

0.22

1.14

* P <0.07.
** 1 US$ = 330 colones.

In both experiments the cost of supplementation was lower when cv. Veraniega was fed fresh or ensiled, which resulted in better economic return to the farmer. Previous reports have indicated that making silage from Cratylia had a high labor cost at ECAG, but this figures have been corrected lately and are comparable to those observed at the farm level (Argel et al., 1999).

Management of C. argentea cv. Veraniega

Cultivar Veraniega can be planted directly from seed. The seed has no dormancy hence seed scarification is not necessary. It should be planted less than 2-cm depth. Establishment is slow. Seed inoculation and fertilization with P is recommended in poor soils. Plants can be cut between 4 - 6 months after planting, preferably at 60-90 cm height, and every 60-90 days to maintain a high protein content. Observations suggest that it is persistent under direct grazing when grown in strips. If the re-growth is not used during the wet season it can be made into silage for dry season feeding.

Limitations

Cultivar Veraniega has slow growth and low production of DM during the establishment year. It does not adapt to poorly drained soils, not to cool environments above 1200 masl in the tropics.

Conclusions

C. argentea cv. Veraniega is an excellent protein supplement that may be offered fresh or as silage to milking cows during the dry season and replace totally or partially expensive concentrates, particularly in dual purpose cattle systems. It is an economical alternative for small farmers.

References

Argel, P. J. (1995) Evaluación agronómica de Cratylia argentea en México y Centroamérica. En: Potencial del Género Cratylia como Leguminosa Forrajera. Pizarro, E. A. y Coradin, L (eds.). EMBRAPA, CENARGEN, CPAC y CIAT. Memorias Taller sobre Cratylia realizado del 19 al 20 de julio de 1995 en Brasilia, Brasil. p. 75-82.

Argel, P. J. y Lascano, C. E. (1998) Cratylia argentea (Desvaux) O. Kuntze: Una nueva leguminosa arbustiva para suelos ácidos en zonas subhúmedas tropicales. Pasturas. Tropicales 20: 37-43.

Argel, P. J.; Lobo Di Palma, M.; Romero, F.; González, J.; Lascano, C. E.; Kerridge, P. C. and Holmann, F. (1999) Silage of Cratylia argentea as a dry season feeding alternative in Costa Rica. Poster presented in FAO Electronic Conference on Tropical Silage, September-November 1999. 3 p.

Jiménez, C.; Pineda, L. y Medina, A. 2000 Uso de aditivos para ensilar Cratylia argentea. En: Informe Final Proyecto Tropileche. Holmann, F. y Lascano, C. (eds.). CIAT e ILRI. (In press).

Lobo Di Palma, M. y Acuña R., V. (2000a) Efecto de la edad de rebrote y altura de corte sobre la productividad de Cratylia argentea cv. Veraniega en el trópico subhúmedo de Costa Rica. En: Informe inal Proyecto Tropileche. Holmann, F. y Lascano, C. (eds.). CIAT e ILRI. (In press).

Lobo Di Palma, M. y Acuña R., V. (2000b) Efecto de la suplementación con Cratylia argentea cv. Veraniega fresca y ensilada en vacas de doble propósito en el trópico subhúmedo de Costa Rica. En: Informe Final Proyecto Tropileche. Holmann, F. y Lascano, C. (eds.). CIAT e ILRI. (In press).

Romero R., F. y González, J. (2000) Efecto de la alimentación durante la época seca con Cratylia argentea fresca y ensilada sobre la producción de leche y sus componentes. En: Informe Final Proyecto Tropileche. Holmann, F. y Lascano, C. (eds.). CIAT e ILRI. (In press).

Schultze-Kraft, R. (1996) Leguminous forage shrubs for acid soils in the tropics. In: Elgersma, A., Struik, P. C. and Maesen, L. J. G. van der (eds.), Grassland Science in Perspective. Wageningen Agricultural University Papers 96-4 (1996). p. 67-81.

Assessment of the nutritive value of leaves of tropical fodder trees and by-products for ruminants as indicated by in vitro gas production and chemical analysis

Rogério M. Maurício[255], Mauricio Rosales[256]

Introduction

The diversity of potentially useful legumes, shrubs and fodder trees for ruminant nutrition in silvopastoral systems is extremely large in the tropics and this is greatly increased when by-products (e.g. crop residues and agro-industrial by-products) are included. Integrated production systems combining both crop and livestock husbandry produces over 80 % of the livestock in the tropics (Jayasuriya, 1993). Therefore, the legumes trees, shrubs, fodder trees and by-products are a valuable feed resource and require intensive investigation. The use of animal response (digestibility, intake, etc.) to attempt to rank feedstuffs is a traditional nutrition research tool. However, these techniques are expensive in terms of feed, labour, time and the facilities required. For more rapid and less expensive initial screening of potential feeds and by-products, in vitro methods are preferable.

The gas production technique released by Theodorou et al. (1994) offers a method of characterising substrates in terms of the kinetics of fermentation, rate and extent of degradation. This technique (Theodorou et al., 1994) was later upgraded by Mauricio et al. (1999) which increased the capacity of the technique and allowed a large number of samples to be examined per incubation series. The aim of this study was to examine the degradation and the fermentation kinetics parameters of 20 fodder plants and 16 agro-industrial by-products and common feeds using the gas production technique and chemical analysis.

Materials and Methods

Samples of leaves from 20 different tropical plant species (Table 1) and 16 by-products (Table 3) were dried, ground (1 mm) and analysed for chemical composition (OM, SPB; soluble protein, lipids, TP; total phenols, NDF, ADF and OM, PB, lipid, NDF, ADF respectively).

Fodder tree samples were analysed using the gas technique described by Theodorou et al, (1994). The rate at which gas was produced by microbial fermentation was measured by incubating 1 g of the sample with 100 ml of solution made up of artificial saliva, redox indicator agent and rumen liquor, in culture bottles over 166 hours. The accumulation of gas pressure and volume in the head-space of culture bottles containing the sample was recorded using a needle, syringe and pressure transducer fitted to a 3-way tap and LED digital readout ammeter. The readings were made at 3, 6, 9, 12, 16, 20, 24, 28, 33, 39, 45, 52, 60, 70, 80, 94, 106, 118, 142 and 166 hours after incubation. The in vitro dry matter digestibility was obtained by vacuum filtration of residual culture solid through a pre-weighed filter crucibles (porosity 1). The gas fermentation parameters were described by modified Gompertz model (Beuvink and Kogut, 1993). The equation describes the potential of gas production and the fractional rates of gas production for rapidly and slowly fermentable material.

The by-products referred in this paper were part of an earlier study where their chemical composition was examined (Silva et al., 1999). The substrates were defined as dried brewery waste (DBW), cotton seed meal (CSM), rice husks (RH), dried whole oranges (DWO), protenose (PR), refinazil (RF), tomato skin bagasse (TSB), babacu (BBC), dende (DN), orange pulp (OP), orange peel (OS), maize grain (MG), soya grain (SB), sorghum grain (SR), wheat (WH) and rapeseed (RS). All the by-products were milled to pass a 1 mm screen and 1.0 g added to a 160 ml fermentation bottle. Rumen liquor was obtained from a cow offered grass a silage: concentrate (60:40) diet; sampling occurred at 07:00 h, before the morning feed, and inocula were prepared according to Mauricio et al. (1999). Each bottle also contained 10 ml inoculum and 90 ml medium. Gas production was measured at 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 and 96 h post-inoculation at 39 ºC using three bottles per substrate. Degradability (expressed as organic matter degradability, OMD) was estimated by filtering fermentation residues (3 replicates) at 6, 12, 24, 48 and 96 hours for all the substrates excepted for DBW, TSB, and RH where fewer intervals were used due to insufficient samples. However, for this paper only OMD at 96 h will be examined. The OMD was determined by drying to constant weight at 100 ºC, and OM obtained by difference following ashing (6 h at 500 ºC). The linear regressions were established using PROC REG (SAS, 1989) relating total gas production and OMD at 96 h. The model of France et al. (1993) was applied to describe, for each substrate, total gas production (TGP), potential of gas production (A), lag phase (L), fractional rate of gas production (µ), and time to achieve half of the asymptote (T/2). With exception for TSB, DN, WH, RS all the substrates were chemically analysed for OM, lipid, NDF, ADF and PB.

Results and discussion

The composition of the feeds is shown in Table 1. Large differences between the samples are not surprising due to the wide variability among plant species. Gas production kinetics are shown in Table 2.

Table 1 Chemical composition of fodder plants

Scientific

Protein

Soluble

Ether

Ash

Organic

Condensed

Total

NDF

ADF

Protein

Extract

Matter

Tannins

Phenols

%

%

Name

%

%

%

%

%

Abs Max/g

Abs/g DM

Amaranthus dubius

18.8

3.7

0.3

18.8

81.1

0

10.0

55.0

36.8

Malvasrum sp.

12.4

1.3

1.7

6.5

93.4

254.1

122.6

57.0

46.8

Bidens pilosa

19.6

5.7

0.4

15.1

84.8

0

35.0

51.7

42.1

Dioclea sericea

12.3

1.3

1.8

5.8

94.1

222.4

68.8

72.4

62.8

Simphytum peregrinum

16.5

4.2

2.2

24.1

75.8

0

70.9

28.1

34.4

Urera baccifera

21.6

4.2

1.5

26.9

73.0

0

1.6

34.5

28.5

Canavalia ensiformis

22.7

4.5

2.4

18.2

81.7

0

23.3

38.2

37.6

Sapindus saponaria

23.6

8.8

1.0

13.4

86.5

0

29.5

43.2

34.3

Heliconia sp.

22.3


5.8

10.7

89.2

0

42.4

51.4

28.3

Tithonia diversifolia

24.2

4.0

1.3

21.4

78.5

0

12.2

35.3

30.4

Clitoria ternatea

29.4

7.4

1.3

8.6

91.3

0

39.7

44.8

34.6

Erythrina edulis

25.6

5.3

2.3

10.8

89.1

0

38.5

61.2

26.4

Enterolobium cyclocarpum

15.6

1.4

4.0

11.5

88.4

251.1

87.9

45.9

44.3

Pithecellobium dulce

17.8

3.7

0.9

10.1

89.8

182.2

67.3

56.6

45.7

Leucaena leucocephala

28.4

4.1

3.2

11.2

88.7

284.1

111.1

30.8

24.7

Trichanthera gigantea

17.8

3.5

3.1

19.5

80.4

0

208.8

29.4

21.7

Inga sp.

22.5

3.0

0.8

9.0

90.9

595.3

151.8

63.0

61.9

Erythrina poeppigiana

21.4

4.7

3.0

17.4

82.5

0

40.3

45.5

40.4

Gliricidia sepium

30.3

12.9

2.2

12.1

87.8

0

39.2

29.8

22.0

Prosopis juliflora

23.4

5.9

1.8

12.9

87.0

0

49.0

31.8

38.8

Table 2 Gas production kinetics of fodder plants



Gas Production
(ml)
Gas Pool Size (ml)

Rate (h-1)

In vitro DM

Rapidly fermentable

Slowly fermentable

Disappearance %

Amaranthus dubius

180.3

186.2

3.88

0.77

70.8

Malvasrum sp.

162.8

166.2

3.39

0.79

52

Bidens pilosa

216.9

219.1

4.12

0.82

76.3

Dioclea sericea

175.6

173.7

1.82

1.74

45.2

Simphytum peregrinum

209.1

206.4

3.98

0.81

74.5

Urera baccifera

183.7

184.3

2.91

1.07

62.5

Canavalia ensiformis

173.4

175.3

3.79

0.63

51.2

Sapindus saponaria

177.7

179.5

2.92

0.42

55.5

Tithonia diversifolia

195.4

198.6

3.66

0.76

69.6

Clitoria ternatea

230

229.1

3.98

0.9

74.6

Erythrina edulis

182.1

183

3.53

0.68

60.9

Enterolobium cyclocarpum

117

117.4

2.14

0.65

47.5

Pithecellobium dulce

125.6

128.6

2.95

1.04

44.7

Leucaena leucocephala

190.7

189.4

2.74

1.26

58.2

Trichanthera gigantea

206.5

218.6

2.83

0.2

60.2

Inga sp.

80.9

82.6

2.12

1.19

30.7

Erythrina poeppigiana

119.3

120.4

2.79

0.72

41.7

Gliricidia sepium

217.3

219.4

3.55

0.49

69.3

Prosopis juliflora

126.5

127.8

1.97

0.7

47.3

There was a poor correlation between OM and gas production for the fodder tree samples. This was due to the presence of condensed tannins and other phenolic compounds which affected negatively the fermentation. The chemical composition was related to the gas production. Rather than predict the gas production completely from the chemical components, the objective of this analysis was to identify which were the main chemical entities contributing to gas production and the time at which such contributions were more important. Results showed that, under nitrogen rich medium, the main components from the leaves affecting the fermentation were: soluble carbohydrates between 3 and 6 hours (P<0.001, r2 = 75.4), soluble protein between 9 and 12 hours (P<0.003, r2 = 52.2), and total phenols and condensed tannins from 28 to 39 hours (P<0.001, r2 = 68.5). There was a highly significant correlation between the gas pool size and the dry matter disappearance measured by filtration of the residue (P<0.001, r2=80.5). However a higher coefficient of determination was expected. This relatively poor fit could be due to the presence of soluble material which is not digested by rumen microorganisms or the production of soluble end products rather than gas. Soluble, indigestible material would not be retained by filtration and hence would be considered to be digested even though the gas production method indicates otherwise.

The by-products chemical composition is shown in Table 3. A highly significant relationship (P<0.001, r2 = 0.91) to predict OMD was obtained from TGP: OMD = -0.007 TGP2 + 4.92 TGP + 82.49. This suggests that although gas production itself is a nutritionally wasteful product (CH4 and CO2) it provides a useful basis from which to estimate OMD.

Table 3 Chemical analysis: OM, lipid, NDF, ADF, PB, OMD and TGP & France parameters: A, lag, T/2 and µ

Substrate

Abrev.

OM

Lipid

NDF

ADF

PB

OMD

TGP

France paramenters

(g/kg/DM)

(g/kg)

(ml)

A (ml)

s.e

Lag (h)

s.e

T/2 (h)

µ (/h)

Dried Brewery waste

DBW

960

10

67

25

20

576

136

135

1,3

1,5

0,2

21

0,027

Cotton seed meal

CSM

950

1

57

36

33

679

162

165

2,8

2,3

0,2

26

0,021

Rice husks

RH

800

1

91

75

3

67

10

-

-

-

-

-

-

Dried whole orange

DWO

970

4

13

14

7

981

342

341

2,6

1,6

0,7

13

0,048

Protenose

PR

970

3

4

8

67

637

135

141

3,2

2,3

0,5

25

0,029

Refinasil

RF

930

3

49

12

24

909

261

259

2,5

1,6

0,5

17

0,041

Tomato skin bagasse

TSB

970

-

-

-

-

474

99

-

-

-

-

-

-

Babacu (type of coconut)

BBC

960

8

-

-

4

177

31

-

-

-

-

-

-

Dende (type of coconut)

DN

970

-

-

-


288

63

-

-

-

-

-

-

Orange pulp

OP

920

5

34

35

7

892

282

281

2,5

2,6

0,2

15

0,011

Orange peel

OS

960

5

31

27

9

963

311

308

2,4

2,1

0,2

16

0,028

Maize grain

MG

990

4

26

5

9

973

329

323

3,7

3,9

0,2

18

0,014

Soya grain

SB

930

1

48

11

54

962

218

215

2,3

2,5

0,2

19

0,024

Sorghum grain

SR

990

3

28

6

10

926

313

310

3,7

4,9

0,2

20

0,013

Wheat grain

WH

940

-

-

-

-

712

222

216

2,5

1,8

0,3

11

0,072

Rapeseed

RS

920

-

-

-

-

764

159

157

2,2

3,5

0,2

16

0,011

Figure 1. Cumulative gas production profiles - a

Figure 1. Cumulative gas production profiles - b

Figure 1. Cumulative gas production profiles - c

Figure 1. Cumulative gas production profiles - d

Within each group, greater variation on gas production profiles were observed (Figure 1) and the impact of those were measured by the France parameters (Table 2). A greater lag phase were associated with lower rate of gas production for most of the substrates. The asymptote values were not achieved during the fermentation for some substrates (RH, TSB, BBC, DN) therefore, the application of the France equation to such values produced erroneous estimates.

Conclusions

This study suggests that the Reading Pressure Technique was able to handle a very wide range of tropical substrates and shows good potential as a technique to rapidly screen diverse feedstuffs in terms of OMD, cumulative gas production profiles and gas production parameters. In the case of fodder plants, the complex relations and interactions between the components of the substrate and the microbial population made difficult a statistically significant fit. This was not the case of the by-products that are more homogenous feedstuffs. This work indicated the need for a better mathematical model to describe the in vitro fermentation.

References

Beuvink, J.M.W. and Kogutk, J., 1993. Modelling gas production kinetics of grass silages incubated with buffered rumen fluid, Journal Animal Sciences, 71: 1041-1046

France, J., Dhanoa, M.S., Theodorou, M.K., Lister, S.J., Davies, S.J. and Isac, D.1993. A model to interpret gas accumulation profiles with in vitro degradation of ruminants feeds. Journal of Theoretical Biology 163:99-111.

Jayasuriya, M.M.1993. Use of crop residues and agro-industrial by-products in ruminant production systems in developing countries. British Society of Animal Production No. 16,47-55.

Mauricio, R.M., Mould, F.L., Dhanoa, M.S., Owen, E., Channa, K.S., Theodorou, M.K. 1999. A semi-automated in vitro gas production technique for ruminants feedstuff evaluation. Animal Feed Science Technology 79:321-330.

SAS, 1989. User´s guide: Statistics. SAS Institute, Raliegh, N. Carolina, USA

Silva Filho, J.C, Armelin, M.J.A., Silva, A.G. 1999. Determination of the mineral composition in agro-industrial by-products used in animal nutrition, by neutron activation. Pesquisa Agropecuária Brasileira 34: 235-241.

Theodorou, M.K., Williams, B.A., Dhanoa, M.S., Mcallan, A.B. and France, J. 1994. A simple gas production method using a pressure transducer to determine the fermentation kinetics of ruminant feeds. Animal Feed Science and Technology 48:185-197.


[176] MSc. Ruminant Nutritionist of ITALCOL. E-mail: anavasc@yahoo.com.
[177] Master Student, CATIE. restrepo@catie.ac.cr
[178] Researcher, CORPOICA.
[179] Ing Agr. IDIAP-CIA CENTRAL. Idiap_cal@cwpanama.net
[180] Ing Agr. IDIAP-CIA AZUERO. Idiap_cal@cwpanama.net
[181] Project CENTA-FAO/Holanda, El Salvador. E-mail: Email: agrisost@es.com.sv
[182] El Hatico Natural Reserve and CIPAV.
[183] El Hatico Natural Reserve and CIPAV.
[184] El Hatico Natural Reserve and CIPAV.
[185] Student Universidad de Caldas
[186] Facultad de Estudios Superiores Cuautitlán UNAM. km 2.5 Carretera Cuautitlán-Teoloyucan, Xhala, Cuautitlán Izcalli, Edo. de México.. 54714. E-mail: lmorfin@servidor.unam.mx
[187] Facultad de Medicina Veterinaria y Zootecnia UADY. Xmatkuil, Yucatán 97100, México
[188] Facultad de Medicina Veterinaria y Zootecnia UADY. Xmatkuil, Yucatán 97100, México
[189] Agricultural Research Station, Pakhribas (ARSP), Dhankuta, Koshi Anchal, Nepal
[190] Stirling Thorne Associates, PO Box 23, Llangefni, Ynys Mon, LL74 8ZE, United Kingdom
[191] School of Agricultural and Forest Sciences, University of Wales, Bangor, Gwynedd, LL57 2UW, United Kingdom
[192] Professor Assistente da Universidade Estadual Vale do Acaraú, Av. da Universidade 850, Betânia, Sobral-Ceará
[193] Pesquisador da EMBRAPA-Caprino, Estrada Sobral-Groaíras, km 4, Cx.P. D-10, 62011970, e-mail ambrosio@cnpc.embrapa.br, Sobral - Ceará.
[194] Universidad del Zulia-Fac. de Ciencias Veterinarias. Dpto. de Producción e Industria Animal. Núcleo Agropecuario. Ciudad Universitaria. Apdo 15252 Maracaibo 4005-A. Estado Zulia - Venezuela.
[195] Universidad del Zulia-Fac. de Ciencias Veterinarias. Dpto. de Producción e Industria Animal. Núcleo Agropecuario. Ciudad Universitaria. Apdo 15252 Maracaibo 4005-A. Estado Zulia - Venezuela.
[196] Universidad del Zulia-Fac. de Ciencias Veterinarias. Dpto. de Producción e Industria Animal. Núcleo Agropecuario. Ciudad Universitaria. Apdo 15252 Maracaibo 4005-A. Estado Zulia - Venezuela.
[197] Centro de Estudios para el Desarrollo de la Producción Animal (CEDEPA), Universidad de Camagüey. Camagüey 74650, CUBA. E-mail: redi@reduc.cmw.edu.cu
[198] Instituto Tecnologico Agropecuario 2, Conkal, Yucatan, Mexico
[199] Universidad Autonoma de Yucatan, FMVZ. (*Author for correspondence: AP # 472 Admon. 1 Central, Merida, Yuc., Mexico CP 97000, e-mail: escobmex@yahoo.com.mx).
[200] Instituto Tecnologico Agropecuario 2, Conkal, Yucatan, Mexico
[201] Universidad Nacional Agraria, Managua, Nicaragua.
[202] Universidad Nacional Agraria, Managua, Nicaragua.
[203] Universidad Nacional Agraria, Managua, Nicaragua.
[204] FORESTAN, Managua, Nicaragua.
[205] CATIE, Turrialba, Costa Rica.
[206] CATIE, Turrialba, Costa Rica.
[207] Centro Experimental Cauquenes. Instituto de Investigaciones Agropecuarias (I.N.I.A.).Casilla 165, Cauquenes. inia-cauquenes@entelchile.net
[208] Centro Regional Quilamapu. Instituto de Investigaciones Agropecuarias (I.N.I.A.).Casilla 426, Chillán. covalle@quilamapu.inia.cl
[209] Centro Experimental Cauquenes. Instituto de Investigaciones Agropecuarias (I.N.I.A.).Casilla 165, Cauquenes. inia-cauquenes@entelchile.net
[210] Centro Regional Quilamapu. Instituto de Investigaciones Agropecuarias (I.N.I.A.).Casilla 426, Chillán. covalle@quilamapu.inia.cl
[211] El Colegio de la Frontera Sur (ECOSUR), Carr. Pan. y Per. Sur s/n, 29200 San Cristóbal de las Casas, Chiapas, México. gjimenez@sclc.ecosur.m
[212] Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán (FMVZ-UADY), Mérida, Yucatán, México.
[213] El Colegio de la Frontera Sur (ECOSUR), Carr. Pan. y Per. Sur s/n, 29200 San Cristóbal de las Casas, Chiapas, México. gjimenez@sclc.ecosur.m
[214] El Colegio de la Frontera Sur (ECOSUR), Carr. Pan. y Per. Sur s/n, 29200 San Cristóbal de las Casas, Chiapas, México. gjimenez@sclc.ecosur.m
[215] El Colegio de la Frontera Sur (ECOSUR), Carr. Pan. y Per. Sur s/n, 29200 San Cristóbal de las Casas, Chiapas, México. gjimenez@sclc.ecosur.m
[216] Experimental Station of Pastures and Forages “Indio Hatuey. Matanzas. Cuba.
[217] Experimental Station of Pastures and Forages “Indio Hatuey. Matanzas. Cuba.
[218] Experimental Station of Pastures and Forages “Indio Hatuey. Matanzas. Cuba.
[219] Experimental Station of Pastures and Forages “Indio Hatuey. Matanzas. Cuba.
[220] Empresa Genética de Matanzas
[221] Centro de Investigación Agricola Tropical (CIAT), Av., Ejercito Nacional 131. Casilla 247. Santa Cruz, Bolivia.
[222] Facultad de Medina Veterinaria y Zootecnia/UADY. Apdo 4-116, CP 97100, Merida Yucatán, México.
[223] Facultad de Medina Veterinaria y Zootecnia/UADY. Apdo 4-116, CP 97100, Merida Yucatán, México.
[224] Centro de Investigación Agricola Tropical (CIAT), Av., Ejercito Nacional 131. Casilla 247. Santa Cruz, Bolivia.
[225] Facultad de Medina Veterinaria y Zootecnia/UADY. Apdo 4-116, CP 97100, Merida Yucatán, México.
[226] Facultad de Medina Veterinaria y Zootecnia/UADY. Apdo 4-116, CP 97100, Merida Yucatán, México.
[227] Facultad de Ciencias Agronómicas. Universidad Autónoma de Chiapas. México. Author: E-mail: llamas62@hotmail.com).
[228] Facultad de Medicina Veterinaria y Zootecnia. Universidad Autónoma de Yucatán, Mexico.
[229] Facultad de Medicina Veterinaria y Zootecnia. Universidad Autónoma de Yucatán, Mexico.
[230] Facultad de Medicina Veterinaria y Zootecnia. Universidad Autónoma de Yucatán, Mexico.
[231] Universidad de Antioquia, Facultad de Veterinaria y Zootecnia, Medellín, Colombia.
[232] Livestock, Environment and Development (LEAD) Initiative, FAO.
[233] Reserva Natural El Hatico, Cerrito, Colombia.
[234] Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Departamento de Nutrición Animal. Vasco de Quiroga No. 15, Tlalpan, 14000, D. F. leonor@aztlan, innsz.mx.
[235] El Colegio de la Frontera Sur (ECOSUR), División de Sistemas de Producción. San Cristobal de las Casas, Chiapas, México
[236] El Colegio de la Frontera Sur (ECOSUR), División de Sistemas de Producción. San Cristobal de las Casas, Chiapas, México
[237] Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Departamento de Nutrición Animal. Vasco de Quiroga No. 15, Tlalpan, 14000, D. F. leonor@aztlan, innsz.mx.
[238] Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Departamento de Nutrición Animal. Vasco de Quiroga No. 15, Tlalpan, 14000, D. F. leonor@aztlan, innsz.mx.
[239] Researcher, Universidad de Costa Rica. E-mail: jbenavid@racsa.co.cr.
[240] Ministry of Agriculture Water and Rural Development, FSRE-U P. Bag 5556 Oshakati, Namibia
[241] Ministry of Environment and Tourism, Directorate of Forestry NFFP P.Bag 508 Outapi, Namibia
[242] Ministry of Agriculture Water and Rural Development, FSRE-U P. Bag 5556 Oshakati, Namibia
[243] FES-Cuautitlán, UNAM. Campo 4. Dpto. de C. Pecuarias. lmorfin@servidor.unam.mx
[244] FES-Cuautitlán, UNAM. Campo 4. Dpto. de C. Pecuarias. lmorfin@servidor.unam.mx
[245] FES-Cuautitlán, UNAM. Campo 4. Dpto. de C. Pecuarias. lmorfin@servidor.unam.mx
[246] University of Chiapas. México
[247] University of Yucatán. Mèxico
[248] University of Chiapas. México
[249] Facultad de Ciencias Veterinarias, Apartado 15252, Maracaibo 4005-A, Venezuela.
[250] Facultad de Ciencias Veterinarias, Apartado 15252, Maracaibo 4005-A, Venezuela.
[251] Facultad de Agronomía. Apartado 15205, Maracaibo, ZU 4005. Venezuela
[252] Facultad de Ciencias Veterinarias, Apartado 15252, Maracaibo 4005-A, Venezuela.
[253] Facultad de Ciencias Veterinarias, Apartado 15252, Maracaibo 4005-A, Venezuela.
[254] Technicians respectively from ECAG, MAG and CIAT Costa Rica.
[255] Fundação Ezequiel Dias, Rua Conde Pereira Carneiro 80, Cep 30510010, B. Horizonte MG Brasil
[256] Livestock Enviroment and Development Initiative, FAO, Via delle Terme di Caracalla, Rome, Italy

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