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A review of the potential of Brachiaria species as forage crop for livestock in Tanzania

N.A. Urio, S.V. Sarwatt and E.J. Mtengeti

Department of Animal Science and Production
Faculty of Agriculture
Sokoine University of Agriculture
P.O. Box 3004, Morogoro, Tanzania


Introduction
Productivity of the species
References


Abstract

Brachiaria spp. is a perennial grass native to East and Central Africa. It has been introduced into humid tropical regions of Latin America, southeast Asia, and northern Australia where it has revolutionised grassland farming and animal production. The potential of Brachiaria spp. in its native land on the other hand, remains largely unexploited.

About 99 percent of Tanzania's ruminant livestock population (22.5 million head of cattle, sheep and goats) derive all their feed from pastures. Hence, there is need to explore productive native pasture species and to provide high management practices so as to increase their yield and quality. The impressive results recorded on Brachiaria in foreign lands, together with a few experimental results recorded in East Africa, indicate that this species could have a significant impact on animal production in East Africa.

This paper therefore reviews research work carried out in Tanzania on Brachiaria spp. in order to stimulate more research on this species.

Introduction

A number of Brachiaria spp. have been recorded in East Africa. These are Brachiaria brizantha, B. ruziziensis, B. serrifolia, B. mutica, B. dictyoneura, B. nigropedata, B. solute, B. humidicola, B. radicans, B. serrate, B. jubata, B. leucocrantha, B. platynota and B. bavonei, (Bogdan, 1955; Van Rensburg, 1960; Mengistu, 1985). The most common of these species are B. brizantha (Signal grass), B. mutica (Pare grass), B. ruziziensis (Congo grass).

Brachiaria brizantha occurs throughout tropical Africa from sea level up to 2400 m under an annual rainfall of over 800 mm (Bogdan, 1977). In East Africa, Bogdan (1955) reported that B. brizantha is very variable and several varieties show striking differences in habit morphology and seed setting capacity. It is possible that the different varieties will perform differently in different ecological zones, but information of this kind is lacking. Low seed viability is probably one of the chief limitations to the wide use of Brachiaria spp. as a forage crop. Identification and development of varieties with good seed setting capacity is one area that ought to receive attention from researchers. B. brizantha has also been noted to be resistant to drought and aggressive, competing effectively with other species and quickly covering the ground (Stomayor-Rios et al., 1960). At Morogoro, Tanzania, a field of Brachiaria brizantha has been maintained for over 20 years without replanting. In Sri Lanka, Brachiaria brizantha has also been reported to perform well under shade of coconut trees (Anken-Lagefoged, 1955). This observation is relevant to Tanzania because a number of dairy and beef farms have been developed in coastal regions where inclusion of this species under coconut trees would greatly improve feed quality and quantity.

Brachiaria brizantha has also been noted to grow and give higher yield when grown on acid rather than alkaline soils (Stomayor-Rios et al., 1960). This characteristic makes it suitable to grow in fallow land after a continuous use of soil acidifying fertilizers such as ammonium sulphate. According to Bogdan (1977), this grass also recovers well from close cutting. This is also supported by observations on fields grown at Morogoro. These attributes make Brachiaria brizantha potentially suitable for the cut-and-carry feeding systems in highland areas of Tanzania. Due to its poor seed-setting characteristic Brachiaria brizantha is normally propagated by use of root stocks. This method of propagation is rather laborious for large-scale establishment but is not a major limitation for smallholder plots.

Brachiaria ruziziensis (Congo grass) is a leafy semi-prostrate, rhizomatous species adapted to humid tropics (Whiteman, 1980). It is less vigorous than Para and Signal grasses. It appears to be more shade-tolerant than Signal grass and thus is more suitable for inclusion under coconut trees. The grass can be propagated both from root stock as well as from seeds.

Brachiaria mutica (Pare grass) is a perennial stoloniferous grass widely grown in the humid tropics and subtropics with rainfall of 1250 mm p.a. This grass has become the backbone of the beef industry in South and Central America, Australia, Philippines and Cuba (Bogdan, 1977). This species is, however, attacked by spittle bug in these areas, and attempts have been made by CIAT to collect germplasm resistant to spittle bug from East Africa. B. mutica is also said to perform well in waterlogged and flooded conditions as compared to B. brizantha and B. ruziziensis. This makes the species particularly suitable for swampy areas. B. mutica forms an open sward and therefore can combine well with legumes particularly Centrosema pubescens.

Productivity of the species

Herbage Dry-Matter Yield

There is considerable literature showing that Brachiaria spp. can give high yields of forage under good climate and management (Table 1). Yields range between 5 and 36 t DM/ha/year depending on soil fertility, moisture and fertilizer application (Bogdan, 1977). There is very little information on the productivity of Brachiaria spp. in Tanzania despite the fact that the grass is indigenous to grasslands there. The little information available is based mainly on Brachiaria brizantha.

Table 1. Influence of Nitrogen rate and cutting interval on the DM yield (t/ha/yr) of Brachiaria spp.

Without fertilizer application, Frederiksen and Kategile (1980), reported a yield of about 3 t DM/ha on a 10-year-old field (Table 2). On fertilizer application yields were raised to about 10 t DM/ha. Kidunda (unpublished data) reported yields of 9.5 t DM/ha on unfertilized newly established plots. Brachiaria spp. generally respond very well to fertilizer application (Tables 2 and 3), and the age of the sward seems to influence both the response and yield. Observations on the 20-year-old swards at Morogoro indicate that very few grass species can compete with Brachiaria spp. on persistence; this makes the species especially valuable in grazing lands. Where irrigation facilities are available, yields per annum could also be raised severalfold.

Table 2. The effect of nitrogen application on the yield, nitrogen utilization, CP % and nitrogen recovery rate on B. brizantha at Morogoro in Tanzania.

N level kg/ha


Yield tons DM/ha

Response kg DM/kg N

IVOMD

CP % of DM

Nitrogen recovery rate

1973

'74

'73

'74

'73

'74

'73

'74

'73

'74

0

2.8

2.9



48

55

5.9

5.5



62.5

5.8

6.2

48

53

54

54

4.6

5.4

38

50

125

8.9

7.6

49

37

54

59

5.4

7.4

42

55

187.5

9.8

8.2

37

28

53

57

7.6

6.1

48

55

*IVOMD = In vitro organic-matter digestibility.
Source: Fredricksen and Kategile (1980).

Table 3. Effect of nitrogen fertilizer application on the annual dry-matter production (t/ha); CP % of DM and yield of CP (t/ha) of Brachiaria ruziziensis and Chloris gayana.



Rate of N

application

(kg/ha/year)

0

224

440

896

1568

2240

Brachiaria ruziziensis


DM yield (t/ha)

6.1

13.9

21.8

26.5

25.9

23.5


CP % of DM

6.7

7.7

10.1

13.9

16.3

16.8


CP % yield (t/ha)

0.6

1.2

2.4

3.6

4.1

3.9

Chloris gayana


DM yield (t/ha)

11.2

20.7

24.5

27.8

26.0

25.4


CP % of DM

8.5

9.3

11.3

14.3

15.7

15.5


CP yield (t/ha)

1.1

1.9

2.8

3.9

3.9

3.9

Source: Olsen (1982) in Uganda.

Nutritive Value

Although no systematic studies have been carried out to evaluate the nutritive value of Brachiaria spp. a number of studies has shown that the species is of high nutritive value. Frederiksen and Kategile (1980) reported about 800 kg CP/ha in the fifth week of regrowth (Table 2) and Nnko, (unpublished data) working on the same plots, which were now 20 years old, reported 400 kg CP/ha at a fertilizer application rate of 105 kg N/ha at eighth week of regrowth. Elsewhere higher yields of CP have been reported with higher N fertilization. In Puerto Rico, Vicente-Chandler et al., (1972), reported yields of 3.5 t of CP/ha at a fertilizer rate of 896 kg N/ha and 60 days cutting intervals for B. ruziziensis. The rate of N fertilizer will certainly be dictated by the economics in a particular area, but if comparative studies are to be conducted with other grass species such as Chloris gayana, Brachiaria spp. is likely to outperform them in this respect.

Brachiaria spp. has been reported to have a fairly high mineral content. Mtengeti (unpublished data), studying mineral status of some pasture species at Morogoro in Tanzania, reported high magnesium content of B. brizantha as compared to other pasture species studied. The species was reported to have fairly reasonable contents of other minerals as well (Table 4). Similar trends of mineral contents were reported by Vicente-Chandler (1959) with B. ruziziensis in Puerto Rico.

Table 4. Mineral composition of B. brizantha at preflowering and flowering stage at Morogoro, Tanzania.

Stage of growth

Ash

Ca %

P %

Mg

K

Ca:P ratio

Cu

Zn ppm

Mn

Pre-flowering

11.20

0.33

0.27

0.24

2.76

1.22

6.9

20.30

63.90

Flowering

10.57

0.33

0.21

0.25

2.88

1.55

3.90

20.44

81.57

Source: Mtengeti (unpublished data).

Although no systematic studies have been carried out at Morogoro to study intake and animal production from Brachiaria spp., observations have indicated preference and higher intakes by cattle for Brachiaria compared to Chloris gayana. In studies carried out in western Tanzania, Kapinga (1986) Reported that Brachiaria spp. was the second most palatable species (after Leucaena spp.) out of eleven species studied.

In countries where Brachiaria spp. has been managed well as a forage crop, standard agronomic practices have resulted in very impressive animal performance. In Tanzania, there is a need to carry out identification, selection and improvement particularly on those varieties that set viable seeds and if possible identify varieties for the different ecological conditions. Combinations of Brachiaria spp. with different legume species have given impressive results elsewhere (Table 5) and are likely to give the same results in Tanzania. This is worth studying and exploiting for optimal production. The fact that Brachiaria spp. has performed extremely well in countries where it has been introduced should act as a catalyst to improve it in its native land and utilise this useful animal feed resource otherwise lying idle.

Table 5. Average stooking rate and cattle liveweight gains on improved pasture.

Pasture


Average stocking rate (beast/ha)


Liveweight gains

Per day

Per year

Rhodes + Stylo

3.7

1.5

543

Para + Centro

4.0

1.8

662

Guinea + Centro

4.0

1.7

614

Guinea + Stylo

3.6

1.6

577

Source: Allen and Cowdry (1961).

References

Allen, G.H. and Cowdry, W.A.R. 1961. Beef gain from irrigated pastures in the Burdekin delta. Queensland Agricultural Journal 87:175-179.

Anken-Lagefoged, A.V. 1955. The role of grasslands in Ceylon's agriculture. Tropical Agriculture 3:257-266.

Appandurai, R.R. and Arassaratnam, R. 1969. The effect of large applications of urea nitrogen on the growth and yield of an established pasture of Brachiaria brizantha (Stapf). Tropical Agriculture 46:153-158.

Bogdan, A.V. 1955. Herbage plants at the grassland research station, Kitale, Kenya. East African Agriculture and Forestry Journal 20:151-165.

Bogdan, A.V. 1977. Tropical pastures and fodder plants. Longman, London.

Car-Costas, R., Vicente-Chandler, J. and Abrunia F. 1976. Comparison of heavily fertilized Congo, Star and Pangola grass pastures in the Humid Mountain region of Puerto-Rico. Journal of Agriculture of the University of Puerto-Rico 40:179-185.

Fredericksen, J.H. and Kategile, J.A. 1980. The effect of nitrogen fertilization and time of cutting in first growth in Brachiaria brizantha on yield, crude protein content and in vitro digestibility. Tropical Animal Production 5:136-143.

Funes, F., Perez, L., and Randa, A. 1980. Growth and development of grasses in Cuba. 2. Effect of three cutting intervals on the yield of eight grasses. Cuban Journal of Agricultural Science 14:181-188.

Kapinga, P.X. 1986. Range development project for western Tanzania. PANESA Newsletter No. 3. ILCA, Addis Ababa.

Mengistu, S. 1985. Survey and collection of forage germplasm in Tanzania. ILCA Germplasm Newsletter No. 10: 16-17. ILCA, Addis Ababa.

Olsen, F.J. 1972. Effect of large application of nitrogen fertilizer on the production and protein contents of four tropical grasses in Uganda. Tropical Agriculture 49:251-260.

Sivalingam, T. 1964. A study of the effect of nitrogen fertilizer and frequency of defoliation on yield. Chemical composition and nutritive value of three tropical grasses. Tropical Agriculturist 120:159-180.

Stomayor-Rios, A., Ve'lez-Forturia, J., Woodburg, R., Schertz, K.F. and Sierra-Biacera, A. 1960. Description and cytology of a form of Signal grass. Behaviour compared to Guinea grass (Panicum maximum IACIC). Journal of Agriculture of the University of Puerto-Rico 44:208-220.

Van Rensburg, H.J. 1960. Ecological aspects of the major grassland types in Tanganyika. Proceedings of the 8th International Grassland Congress, Reading, England. pp. 307-393.

Vincente-Chandler, J., Servado Silva, S. and Fisarello, J. 1959. Effect of nitrogen fertilization and frequency of cutting on the yield and composition of Para grass in Puerto Rico. Journal of Agriculture of the University of Puerto-Rico 43:215-48.

Vincente-Chandler, J., Silva, S., Albrunia, F. and Rodriguez, J.A. 1972. Effect of two cutting heights, four harvest intervals and five nitrogen rates on yield and composition of Congo grass under humid tropical conditions. Puerto Rico Journal of Agriculture 56:80-291.

Whiteman, P.C. 1980. Tropical Pasture Science. Oxford University Press, New York.


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