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The adoption of improved cassava varieties and their potential as livestock feeds in southwestern Nigeria


Cassava varieties in southwestern Nigeria
Level of adoption of improved cassava varieties in southwestern Nigeria
The sociology of cassava adoption and spread
Cassava as a livestock feed resource
The economies of cassava as a livestock feed resource
References

M.O. Akoroda and A.E. Ikpi

The beginning of cassava cultivation along the coastal parts of Nigeria has been recognized as early as 1667 and is traceable to Portuguese explorers and emancipated slaves from Brazil and the West Indies who had landed on the southern coast of Nigeria between the Bonny and Koko ports. Thus, cassava may actually have been introduced into Nigeria over 300 years ago although its systematic cultivation was never generally accepted and practiced until the late 1890s. Cassava became generally accepted and fully integrated into the farming systems of southern Nigeria a little over 130 years ago (Ekandem 1962, 1964; Agboola 1968, 1979).

Agboola (1979) states that cassava was moved from Fernardo Po to the Warri area of Nigeria but its cultivation was not widespread until the turn of the nineteenth century. "As late as 1930, cassava had only mace little in-road into Iboland". According to Agboola (1968), "emancipated slaves from Brazil, the West Indies, and Sierra Leone who returned to parts of Southern Nigeria after the 1850s, played an important role in stimulating the acceptance of cassava". These returnee; who knew how to process the crop into food, settled largely among the local people of Lagos, Badagry, Abeokuta and Ijebu to whom they imparted their knowledge and also popularized the consumption of cassava in the local food economy. Eventually, demand for processed forms of cassava (gari, fufu, lafun, etc.) developed.

Cassava is not a principal carbohydrate crop in those parts of Nigeria approximately south of latitude 8°N which is described as southwestern Nigeria. In this zone, enclaves exist where yam, cocoyams and plantain dominate or are equal in importance to cassava.

The southwestern portion of Nigeria lies west of River Niger and south of altitude 8°N. Though diverse, 14 areas (figure 1) can be distinguished that are uniform as regards people, agroecology, farming and food patterns. A straight line from near Ibadan, through Ohosu and Agbor approximately bisects the region (figure 1).

The area has medium to high population densities and is well connected with roads for long hauls of agricultural produce. The dominant tribes are Yoruba, Edo, Ibo, Urhobo and Isoko, all of whom consume cassava as gari - the chief cassava product of commerce.

Research on the improvement of cassava has also been largely undertaken in this area, particularly at Ibadan by the Federal Department of Agricultural Research (FDAR) in Moor Plantation, IITA, and the University of Ibadan.

Figure 1: Map of Nigeria showing states in the southwest (Oyo-A, B; Ondo-C, G; Ogun-E; Lagos-F; Bendel-D, H. 1, J. K, L, M; and western part of Rivers-N)

Though soil types vary, food crops grown bear little relation to changes in soil types. Sun hours vary widely from 22.5 hr in A to less than 15.0 hr in N (figure 1). Most of this area is within the high rainforest zone with an annual rainfall of 1250-4000 mm, but the average is about 1500 mm.

Cassava varieties in southwestern Nigeria

It had been suggested that before modern research on cassava started in Nigeria in 1954 at the FDAR, Ibadan, there were numerous local ecotypes of traditional clones. These varied in their tuber yields and general tolerance of prevailing pests and diseases. ''Oloronto" (53101), a local cultivar from the Ibadan/Abeokuta area, was then recommended for southwestern Nigeria. It was later used in crosses in 1967 which led to the release of improved varieties such as 60444, 60447 and 60506 for the whole country.

In 1972 when cassava bacterial blight (CBB) became a scourge for cassava in the country, only 60306 and a few local types tolerated the disease. Breeding work at IITA later identified improved clones which were released after 1976. Releases of the first two IITA clones, namely TMS 30211 and TMS 30395, were rapidly followed by TMS 30572, TMS 30001, TMS 300017, TMS 30110, TMS 30337, TMS 30555, TMS 4(2)1425 and others (IITA 1984).

These improved varieties differed in their resistance to cassava diseases and pests such as CBB, cassava mosaic virus (CMV), cassava anthracnose disease (CAD), cassava mealybug (CMB) and cassava green spider mite (CGM). They also produced tubers with varying quality of roots at differing maturity duration and storage in the ground (table 1). These improved varieties always gave high yields (Okigbo 1978, Hahn 1983, Herren and Bennett 1984, IITA 1984, and Otoo and Hahn 1987). Farmers preferred improved varieties because of their higher yields, earlier maturity, high supression of weeds, and greater resistance to diverse diseases and pests (Akoroda et al. 1985, 1987; Ikpi et al. 1986).

A wide variety of cassava cultivars can now be observed in farmers' fields but one or two cultivars may occur more frequently in a given zone. Thus, the most commonly observed local cultivars in southwestern Nigeria are (a) "Odongbo" with its reddish petiole, cream-colored stem, moderate branching, and clear white flesh; (b) "Oyarugba dudu" with indeterminate growth habit, dark stem, and cream-colored petiole; (c) "Eye dudu" which is very similar to TMS 30572 and whose origin is suspected to be from IITA's stock dispersed by some extension staff in the early 1970s; and (d) "Isunikankiyan", a high-branching, erect cassava variety with reddish petiole, stem and periderm, usually early-maturing, mealy and sweet.

Normally, a field of cassava in southwestern Nigeria may contain different combinations of all four varieties including some other minor cultivars. However, the most commonly grown local variety in southwestern Nigeria is Odongbo - which bears different names in different parts of southwestern Nigeria, e.g. Jejeti in Warri, Bendel state.

Level of adoption of improved cassava varieties in southwestern Nigeria

The cultivation of improved cassava cultivars in different parts of southwestern Nigeria has been unequal principally because of their levels of yield performance and age of maturity (Otoo and Hahn 1987, Ikpi 1988). Table 1 summarizes the comparative performance of early and recent releases of improved IITA cassava varieties.

More recent releases such as TMS 4(2) 1425, TMS 50395, and TMS 30572 are doing much better in farmers' fields than earlier releases such as clones 60506 and TMS 30001 (table 1).

Socioeconomic surveys of cassava adoption in southwestern Nigeria (Ay et al. 1983, Keyser 1984, and Ikpi et al. 1986) confirm that adoption levels depend on many factors, such as: (a) vegetation characteristics of area with regard to its suitability for growing other crops; (b) population density (which influences the number of cassava farmers that could adopt new improved varieties); (c) tribal preferences which restrict cultivation of cassava to poorer farmers who lack land and cash to expand cassava hectarage upon adoption of improved varieties; (d) relative competition with cassava in each locality by other carbohydrate crops, e.g. maize, yam, and plantain; (e) proximity of high density population that does not farm but consumes cassava as gari; (f) local presence and capacity of the propagule distribution agency as source of planting materials for small farmers; and (g) farmers' own perception of overall benefits from improved cassava varieties relative to local varieties. This farmers' perception of benefits is not only based on superior yields of fresh tuber, but also on harvest duration, quality of processed product for food, labor needs and-general economics of the improved varieties within local situations.

Table 1: Comparative performance of early and recent improved cassava varieties of IITA in southwestern Nigeria

Variety

Root yield (t/ha)

% of check

Harvest duration (months)

Root HCN content (mg/100g)

Source of clone

TMS 4(2)1425

20.9

211.1

9-15

3.12

IITA

TMS 30001

13.2

133.3

9-15

3.95

IITA

TMS 30572

14.4

145.5

9-15

4.99

IITA

TMS 50395

14.4

145.5

9-15

4.99

IITA

60506 (check)a

9.9

100.0

15-18

4.51

FDAR

Source: Umanah (1976), Otoo and Hahn (1987)
Note: a Clone used as check in IITA breeding work, yielded 38.7 t/ha before advent of many new diseases and pests

An-overview of the level of adoption of improved cassava varieties on a scale of 1 to 5 (where 1 is little or no adoption, and 5 is intense or almost total adoption with over 75 percent of the cassava hectarage being planted with improved varieties) is presented in table 2. An average adoption rate of 2.7 has been observed which is a statistically better-than-average rate of adoption for the zone.

In terms of actual hectarage cultivation of improved versus local/traditional varieties of cassava, Ikpi et al. (1986) showed that in Oyo state alone, there was a 25 percent level of adoption of improved cassava varieties within the cropping systems of the people. A more-recent evaluation of 1987 plantings (Ikpi 1988) covering 360 farmer respondents in Oyo, Ondo, and Kwara states, showed that the level of adoption of some of these improved cassava varieties had increased appreciably to 36.0% in Oyo (Oyo State), 47.2% in Oyun (Kwara State) and 34.8% in Owo (Ondo State). This gave an estimated average of 39.3% level of adoption in southwestern Nigeria (table 3). In other words, approximately 34% of the farming population of these three states adopted and planted improved cassava varieties on their farms.

The levels of adoption of improved cassava varieties summarized in table 3 show an annual rate of increase of 11% for Ondo State and 22% for Oyo State, giving a generalized average annual rate of increase of adoption of 16.5% for southwestern Nigeria. At that estimated average annual rate of increase and assuming that all other adoption factors hold, it will take approximately six years from 1988 for all the farmers in the zone to adopt improved varieties of cassava. This should be seen as the challenge of the next decade (1990]) for the national agricultural research system (NARS) and agricultural extension systems.

Table 2. Environmental variables in relation to the adoption of improved cassava varieties in sectors of southwestern Nigeria

Sector code

Sector name sectora

Main agro- ecology of cultivationb

Farmland for food crop staples

Population density

Relative status of cassava to other local

Improved cassava adoption ( 1 = least 5 = intense)

A

Oyo North

G-D

+

Low

C/M.Y.S.

1-2

B

Oyo South

R

-

High

> Y.M.

3-4

C

Ondo Inland

R-D

-

Moderate

C/M.Y.

2-3

D

Bendel North

R-D

+

Low

C = Y.M

1-2

E

Ogun State

R

-

Moderate

<

4-5

F

Lagos State

M-F

-

High

C Y.M

3-4

G

Ondo Littoral

M-F

-

Low

C P

2-3

H

Bendel Edo

R

-

Moderate

C Y.P

3-4

I

Bendel Ibo

R

-

Moderate

C/Y.P

1-2

J

Bendel Warri

M-F

-

Low

C>

2-3

K

Bendel Ethiope

F

-

Moderate

C>

4-5

L

Bendel Isoko

F

-

Moderate

C>

3-4

M

Bendel Ijaw

M-F

-

Low

C=/P

1-2

N

Rivers Ijaw

M-F

-

Low

C/=P

1-2

Notes: a G = guinea savanna, D = derived savanna, R = rain forest, M = mangrove swamp forest, and F = freshwater forest
b + is sufficient, - is deficient,
c C = cassava, M = maize, Y = yam, P = plantain, S = sorghum; and the symbols: / is secondary to, = is co-equal with,... > is dominant, is dominant over or co-equal with, is other starchy staples.

Table 3. Levels of adoption of Improved cassava varieties In Kwara, Oyo and Ondo States of Nigeria

LGA/State a

No. of respondents

Average ha. cultivated to level of adoption (%)

Annual rate of increase

Improved

Local

Total

1985

1987

% change

Oyun, Kwara

108

0.89

0.66

1.55

na

47.2

nd

nd

Owo, Ondo

112

0.70

1.37

2.07

28.5

34.8

22

11%

Oyo, Oyo

140

0.70

2.13

2.83

25.0

36.0

44

22%

Average

120

0.76

1.39

2.15

na

39.3

nd

16.5%

Source: Ikpi 1988
Note: a LGA = Local Government Area
na = not available, nd = not determined

The sociology of cassava adoption and spread

Adoption of improved cassava cultivars begins from the decision of farmers to replace old inferior varieties or to supplement their stock of planting materials with new improved varieties or simply by extending cultivated land areas. Mathematical extrapolations of areas presumed to be plantable from the annual increase of distributed cuttings are insufficient to explain the pattern of adoption of improved varieties.

In southwestern Nigeria, the spread of suitable crop varieties does not usually follow commercial pathways. Family relations and neighborhood friends first receive gifts of cuttings from primary recipients. Occasional sale of propagules occurs only where buyers appreciate the benefit which they could derive from growing such new varieties. Perhaps the most important step in adoption is farmers' awareness of the qualities of improved varieties. Ordinarily, methods used to create awareness among farmers include (a) on-farm trials; (b) demonstration plots controlled by agricultural extension agents; (c) field days for farmers; (d) agricultural shows to which farmers are invited; and (e) personal experience through trial planting, since some farmers are always willing to test any new variety on a small part of their farm.

We believe that awareness promotes demand, and demand is a force for rapid adoption and spread. Where farmers receive some cuttings of a new variety without a proper knowledge of its novelty or superiority, they simply plant it. They do not inspect it or evaluate its performance relative to local varieties. Consequently, the new variety is mix-planted with other varieties and such adoption cannot be followed and assessed.

One social aspect in the distribution of cassava is that the rate of spread from one village to the other is very slow or nonexistent in some cases. Thus, spread is almost confined to within the village. The concept of community multiplication farms particularly in small villages has been tested and proved superior to individual ownership or engagement in propagule multiplication.

Spread from one village to the other also depends on the presence and frequency of contacts which may be familial, commercial, or sociocultural (agricultural shows, communal ceremonies etc.). With better communications by road and water information on the performance of new varieties is circulated more readily through personal contacts. Where the level of adoption in a village is high, that is, the number of growers who agree to continue the cultivation the new varieties as a percentage of those who originally received it, spread is also likely to be high. This is because more people tend to inform others or move propagules to other localities.

The movement of a variety from one location where it was originally deposited to another location is regarded as spread, which may be of two kinds. First, materials may move from a farmer who has originally received it in location A to a farmer in location B where the material has never been distributed. In the second type of spread, a farmer in location X may send materials to a farmer in location Y where farmers already have the same variety. Both types of spread occur randomly and can be estimated by sample surveys and reconnaissance.

It is necessary to sketch the adoption and spread of new varieties five years after their initial release from a research agency. In this way, early action can be taken to derive more benefits from the potentials of improved cassava varieties.

Many factors govern the adoption of new cassava varieties. Under normal circumstances, the willingness of farmers to test and continue to grow new varieties increases with real yield differences between cassava varieties when they are planted in their own fields with their own level of crop management; the availability of local markets that can absorb all or most of farm output at fair prices; reduced or no increase in demand for family labor for production, processing, transportation, and marketing of produce; and little or no need for new inputs or difficult operations within prevailing cropping systems. One important point is that farmers in many localities differ in their principal motive for cultivating cassava. There are also several microenvironmental variables that combine to influence adoption of new varieties. These variables specifically include (a) road outlet for output from cassava farms; (b) transport system; (c) cost of product relative to that of transportation; (d) the absorptive capacity of local markets to which farmers sell their cassava tuberous roots; (e) quantity of plantable stems that reach a cassava farmer at planting time; and (f) quantities of planting stems from the field of a farmer that are replanted after each harvest of the season's crop.

Some changes are inevitable if new varieties must be used. The duration of crop growth implies new planting and harvesting dates. A 12-month cassava variety must not be harvested in 24 months or at other times. The yield potential of a new variety is usually not attained under peasant farming because of mixture of several varieties, poor crop handling, low soil fertility, crop mixtures, suboptimal stem quality, and stand population. Adoption of varieties does not, therefore, depend only on the presence of inputs which enable farmers to obtain maximum yields.

Cassava as a livestock feed resource

Since the early 1930s cassava has been known and used as a livestock feed substitute instead of grains for poultry and rations. The first large-scale commercial users and adopters of cassava as a livestock feed resource were livestock farmers of the European Economic Community (EEC). Cassava as a substitute resource in livestock-feeds became fashionable first because of its relative cheapness compared with grains (especially corn) and later because of the increased demand of corn for human and other industrial uses such as in textiles, breweries and bakeries.

Several nutritional and feeding experiments on the potentials of cassava as a substitute for grain have been carried out since the time Tabayoyong (1935) first incorporated 30% and 60% levels of cassava starch extract into chicken diets (McMillan and Dudley 1941, Klein and Barlowen 1954. Vegt and Penner 1963, Vegt and Stute 1964, Vegt 1966, Barrios and Bressani 1967, Rendon et al. 1969, Montilla et al. 1969, Olson et al. 1969, Montilla 1970, Maust et al. 1972, Chou and Müller 1972, Armas and Chicco 1973, Müller et al. 1974, Hutagalung et al. 1974, Montilla et al. 1975, Adegbola-1976, Enriquez and Ross 1967, Gadelha et al. 1969, Obiora 1978, Olson et al. 1968, Phuah and Hutagalung 1974, Squibb end Wyld 1978, and Adesida 1979). The major findings of these studies may be summarized as follows:

1. Cassava can be substituted as a feed ingredient for corn and/or other grains without negatively affecting poultry feed consumption.

2. The nutritive content and value of cassava meal in livestock feed depends on the cassava variety used, the age of the cassava tuber, and the processing technology used in producing the cassava meal.

3. Low-HCN cassava varieties (sweet) are preferred by chickens to high-HCN cassava varieties (bitter).

4. Levels of substitution of cassava for grain higher than 20% produce deleterious effects on the health of chickens and cause reduction in weight gain and feed conversion efficiency, especially after the fourth week.

5. Excessively fine (powdery) nature of cassava flour influences the feed intake negatively and diminishes consumption of cassava meal.

6. Cassava pellets can be used up to 20% level without any adverse effect on the birds provided that the diets are balanced with other nutrients.

7. The level of cassava substitution in the chicken (especially broiler) ration can be increased beyond 20% by adding 5% animal fat in order to reduce the powdery nature of the cassava-based rations.

8. When added as a moderator in cassava-based poultry rations, methionine improves the quality and utilization of the dietary protein in the ration by detoxifying the prussic acid which is normally released during the hydrolysis of linamarin and lotaustralin in the cassava meal/flour, thereby increasing feed palatability. Without methionine supplementation, birds deteriorate in weight gain at three weeks of age, with significant differences in feed conversion efficiency when cassava levels exceed 20%.

9. Addition of molasses and soybean oil to cassava-based rations does not have any beneficial effects.

10. Addition of animal fat and soybean flour makes cassava-based rations isocaloric and isoproteinaceous and increases digestibility of the protein in the ration.

Three important studies conducted in Nigeria deserve special mention. Adegbola (1976) showed that the quality and utilization of the dietary protein in a properly balanced diet could be improved through the addition of methionine to cassava-based rations. He revealed that the methionine served as the detoxicant of any prussic acid released during the hydrolysis of linamarin and lotaustralin. He also drew attention to the need to relate responses to added methionine in rations to the levels of protein in the diet as well as to the nature and palatability of the feed. He stressed that methionine shares its role with other sulfur-donors such as cystine, thiosulfate and elemental sulfur, but is preferred to the others because it is a metabolizable essential amino acid that yields cystine.

Obiora's study (1978) showed that gari could replace maize in broiler finisher rations. He found that the feed conversion efficiency was best when the feed contained a gari-to-maize ratio of 29:24.5%. He concluded that gari could replace all the maize in a broiler finisher diet or constitute up to 49% of the whole ration without any decrease in growth rate or carcass quality; provided the ration was balanced for protein and amino acids. He gave the best substitution level of gari as 50% or 29% of the whole ration.

Adesida (1979) used a linear programming model to determine least-cost broiler rations that substituted cassava for maize and found that with cassava prices at 150.00 per tonne, the optimum mix required a maximum level of 30% cassava and that the cost of feed increased as the price of cassava increased. She also found that there was a gradual reduction in weight gain as cassava levels increased beyond 8% in starter diets.

The economies of cassava as a livestock feed resource

Although studies have been conducted on livestock feeds and feeding using cassava, the economics of substituting cassava for maize has not been systematically considered. Until 1985, cassava was relatively cheap (low priced) in southwestern Nigeria, costing 30.00 for 200 unharvested stands in the field or an estimated 120.00 per tonne. By 1988, three years later, cassava prices had increased to between 1250.00 and N280.00 for 200 unharvested stands in the field, calculated to be equivalent to between 400.00 and 1500.00 per tonne of tubers.

At a conversion rate of 25% at which fresh cassava tubers are converted into useable cassava meal or flour that can be incorporated into poultry rations, it is calculated that for every tonne of fresh cassava produced, only 250 kg of cassava flour will be available as livestock feed. Secondly, given that other carbohydrate sources, such as corn, usually constitute a minimum of 75 percent of the weight of finished rations, to prepare 1 tonne of poultry feed using only 20% substitution level of cassava for maize will require 62 kg of cassava meal per tonne of finished ration. This will cost approximately 375.00 for the cassava component needed. When included in the costing, the necessary protein, amino acid (methionine) and antibiotic supplementation will increase the price further. For example, incorporating methionine and soybean meal alone will double these costs. Thus, cassava may be substitutable for maize but cost considerations do not give it high recommendation.

References

Adegbola, AA. 1977. Methionine as an additive to cassava-based diets. Pages 9-17 in Proceedings, Cassava as Animal Feed Workshop, edited by B. Nestel and M. Graham, University of Guelph, 18-20 April 1976, Ontario, Canada. IDRC: Ottawa.

Adesida, M. 1979. Least-cost rations for broilers using linear programming. PhD thesis. University of Ibadan, Nigeria.

Agboola, S.A. 1968. Patterns of food crop production In southwest Nigeria. Nigeria Geographical Journal 11(2): 135-152.

Agboola, S.A. 1979. An agricultural atlas of Nigeria. Oxford University Press.

Akoroda, M.O., I. Gebremeskel, and AK. Oyinlola. 1985. Impact of IITA cassava varieties in Oyo State of Nigeria. IITA, Ibadan, Nigeria. 105 pp.

Akoroda, M.O., A.E. Oyinlola, and T. Gebremeskel. 1987. Plantable stem supply system for IITA cassava varieties in Oyo State of Nigeria. Agricultural Systems 24(4): 305-317.

Armas, A.B., and C.F. Chicco. 1973. Evaluación de la harina de yuca (Manihot esculenta) en raciones pare pollos de engorde. Agron. Trop. (Maracay): 23(6): 593-599.

Ay, P., O.R. Oyediran, and D.A. Ogunsakin. 1983. IITA cassava now part of local farming system: variety 30572 supplements local varieties and opens new production opportunities. Farming Systems Program Report, IITA, Ibadan, Nigeria.

Barrios, E.A., and R Bressani. 1967. Composición química de la ráiz y de las hojas de algunas variedades de yuca (Manihot esculenta). Turrialba 17(3): 314-320.

Chou, K.C., and Z. Müller. 1972. Complete substitution of maize by tapioca in broiler rations. Pages 149-160 in Proceedings, Australian Poultry Science Convention 1972, Auckland, New Zealand. New Zealand World Poultry Science Association.

Ekandem, M.J. 1962. Cassava in Nigeria. Eastern Nigeria Memo No. 42. Federal Department of Agricultural Research, Ibadan, Nigeria.

Ekandem, M.J. 1964. Cassava investigations carried out in Northern Nigeria. Memo No. 55. Federal Department of Agricultural Research, Ibadan, Nigeria.

Enriquez, F.Q., and E. Ross. 1967. The value of cassava root meal for chicks. Poultry Science 46: 622-626.

Gadelha, J.A., J. Campos, and V. Mayrose. 1969. Farelo de raspa de mandioca na alimentação de pintos. Experientiae 9(4): 111-132.

Hahn, S.K. 1983. Cassava research to overcome the constraints to production and use in Africa. In Proceedings, Cassava Toxicity and Thyroid: Research and Public Health Issues, edited by F. Delange and R. Ahluwalia, 31 May - 2 June 1982, Ottawa, Canada.

Herren, H.R., and F. D. Bennett. 1984. Biological control of cassava pests. In Advancing agricultural production in Africa. Proceedings, CAB's Scientific Conference, edited by D.L. Hawksworth, 12-18 Feb. 1984, Arusha, Tanzania.

Hutagalung, R J., S. Jalaludin, and C. C. Chang. 1974. Evaluation of agricultural products and by-products as animal feeds. II. Effects of levels of dietary Cassava (tapioca) leaf and root on performance, digestibility and body composition of broiler chicks. Malay. Agric. Res. 3:49-59.

Hutagalung, RJ., C.H. Phuah, and V.F. Hew. 1974. The utilization of Cassava (tapioca) in livestock feeding. Paper presented at the Third International Symposium on Tropical Root Crops, 2-9 December 1973, IITA, Ibadan, Nigeria.

IITA (International Institute of Tropical Agriculture). 1984. Annual report 1984. Ibadan, Nigeria.

Ikpi, A. 1988. Monitoring and evaluating household food security and nutrition projects. IITA-UNICEF Collaborative Program Report, IITA, Ibadan, Nigeria.

Ikpi, A, T. Gebremeskel, N. D. Hahn, H. Ezumah, and J.A. Ekpere. 1 986. Cassava a crop for household food security. IITA-UNICEF Collaborative Program Report, IITA. Ibadan, Nigeria.

Keyser, J. 1984. Yoruba names mirror Cassava traits. IITA Research Briefs 5(4): 3, 6 &8.

Klein, W., and von G. Barlowen. 1954. Tapioca mehl in aufzuchfutter. Arch. Geflügelkd 18: 415-528.

Maust, L.E., M.L. Scott, and W.G. Pond. 1972. The metabolizable energy of rice bran, Cassava flour, and blackeye cowpeas for growing chickens. Poultry Science 51: 13971401.

McMillan, A M., and F.J. Dudley. 1941. Potato meal, tapioca meal, and town waste in chicken rations. Harper Adams Utility Poultry Journal 26(9):191-194.

Montilla, J.J. 1970. Utilización de la harina de raíz de yuca (Manihot esculenta) en raciones pare pullos de engorde. In Commun. Cient, XIV Congr. Mundial Avicult., Madrid, Espana. 985 p.

Montilla, J.J., C.R Mandez, and H. Wiedenhofer. 1969. Utilización de la harina de tubérculo de yuca (Manihot esculenta), en raciones iniciadoras pare pollos de engorde. Arch. Latinoam. Nutr. 19(4): 381-388.

Montilla, J.J., P.P. Castillo, and Wiedenhofer. 1975. Efectos de la incorporación de harina de yuca amarga en raciones pare pollos de engorde. Agron. Trop. 25: 259266.

Müller, Z., K.C. Chou, and KC. Nah. 1974. Cassava as a total substitute for cereals in livestock and poultry rations Pages 85-95 in Proceedings of the Tropical Products Institute conference of 1-5 April 1974.

Obiora, O. 1978. The grain replacement value of processed Cassava in broiler finisher rations. Nigerian Journal of Animal Production Vol. R.N. 2: 217.

Okigbo, B.N. 1978. Cropping systems and related research in Africa. Association for the Advancement of Science in Africa (AASA), Occasional Publication Series-OT-1.

Olson, D.W., M.I. Sunde, and H.R. Bird. 1969a. Amino acid supplementation of mandioca meal in chick diets. Poultry Science 48: 1949-1953.

Olson, D.W., M.I. Sunde, and H.R. Bird. 1969b. The metabolizable content and feeding value of mandioca meal in diet for chicks. Poultry Science 48: 1445-1452.

Olson, D.W., M.I. Sunde, and H.R. Bird. 1968. Metabolizable energy and feeding value of mandioca meal. Poultry Science 47: 1703.

Otoo, J.A., and S.K. Hahn. 1987. Performance of TMS 4(2) 1425 is outstanding. IITA Research Briefs 8(3): 8.

Phuah, C.H., and R.I. Hutagalung. 1974. Effect of levels of dietary protein and cassava on performance and body composition of chickens. Malay Agric Research 3: 99106.

Rendón, M., H. Bénitez, and O. Marin. 1969. Utilización de la yuca (Manihot esculenta) en el engorde de pollos asaderos. Rev. ICA 4(3): 159- 171.

Squibb, RL., and M.K. Wyld. 1951. Effect of yuca meal in baby chick rations. Turrialba 1(6): 198-299.

Tabayoyong, T.T. 1935. The value of cassava refuse meal in the rations for growing chicks. Philippine Agriculture 24:209.

Umanah, E.E. 1976. Cassava research in Nigeria before 1972. Pages 137-141 in Proceedings, Fourth Symposium of the International Society for Tropical Root Crops, edited by J. Cock, R MacIntyre and M. Graham, IDRC: Ottawa.

Vegt, H. 1966. The use of tapioca meal in poultry rations. World Poultry Science Journal 22: 113-125.

Vegt, H., and W. Penner. 1963. Der einsatz von tapioca-und maniokamehl im Geflügelmasfutter. Arch. Geflugelkd. 27: 431.

Vegt, H., and K Stute. 1964. Prugung von tapiocapellets im Geflügelmast-Alleinfutter. Arch. Geflugelkd. 28: 342.


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