by E.O. Otchere
The importance of small ruminants in the tropics in general is well recognised (Williamson and Payne, 1978). Small ruminants are reared mainly for four functions, namely: (1) Meat, (2) milk,(3) skin and (4) wool, according to order of importance. According to the FAO (1982) tropical Africa has about one-sixth and about a third of the total world flock of sheep and goats, respectively. Total meat produced from small ruminants in Africa was 1.3 million metric tonnes (about 16% of the world total from sheep and goats). Within Africa, sheep and goats contributed 10.9% and 8.4%, respectively, of our total meat. Total meat from African sheep and goats contributed 12.0%, respectively, of the world total meat production from these two species. Sheep and goats in Africa produced 8.6% and 18.2% respectively, of the world total amount of milk produced from these two species and the production from both accounted for 13.6% of milk collected from small ruminants in the world. According to Wilson (1982), sheep and goats accounted for 17% of the total ruminant biomass in Africa. Table 1 shows the population of sheep and goats in Africa and the amount of meat and milk produced from them as compared with world figures.
DISTRIBUTION, OWNERSHIP AND FLOCK SIZE
The distribution of sheep and goats in Africa is not even and numbers tend to be higher in the drier areas. Consequently, flock sizes are larger in the drier than in the humid areas. Thus, in some areas (e.g. in West Africa) flock sizes decrease from north to south (ILCA, 1979; Otchere et al. 1985). In East Africa (e.g. Ethiopia and Kenya) flocks are smaller in the highlands compared with the lowlands (Wilson, 1982). Flock sizes are generally larger in the pastoral and smaller in the humid agricultural regions (ILCA, 1979; Bayer, 1984). Tables 2–4 show the general pattern of ownership and flock sizes in arable, pastoral and agro-pastoral societies in Nigeria, Kenya Tchad, and Mali. The data suggests that the pattern of ownership of small stock in Africa is rather varied and extremely complex. The majority of small ruminants is owned by individuals or families in rural areas and the number per group is small. Small stock nevertheless form an integral part of the farming system (Wilson).
Van Vlaenderen (1985) described sheep and goat husbandry in Togo as being casual rather than an organised activity for the following reasons: (a) animals have no benefit of prophylactic or curative medicinal treatment: (b) littre or no supplementary feed is offerred; (c) no good flock management is practised; (d) poor housing (e) tethering of animals during the planting season so as to avoid crop damage. The above criticism will seem to apply to small ruminant production in traditional systems throughout tropical Africa. According to Wilson (1982), however, Africans who keep small stock rarely do so for irrational reasons and that such reasons are perfectly in keeping with the problems encounterred and the specific objectives of the owners. Table 5 shows that there appears to be a similarity of sheep or goat flock structures in the traditional system of small ruminant production across different zones of tropical Africa.
International Livestock Centre for Africa (ILCA), P.O. Box 2248, Kaduna, Nigeria.
Small ruminants are widely distributed and are of great importance as a major source of livelihood of the small farmer and the landless in rural communities in tropical Africa. Indications, however, are that the productivity of small ruminants in this system is low and that there is ample opportunity for improvement.
Age at first parturition, parturition interval and litter size determine lifetime production as well as efficiency of production. Genetic improvement and or efficiency of production can be more easily ameliorated in small ruminants because they have a faster population turnover rate. Such progress would be achieved if increased selection pressure is effectively applied. Several of these production parameters can be improved because they are under the influence of environmental and ecological factors. Available data suggest that reproductive efficiency of small ruminants in tropical Africa is reasonably high and hence fertility would not be recommended for any improvement unless present nutritional, health and management constraints are removed.
Of paramount importance to economic productivity and reproductive efficiency in small ruminants is mortality. Both pre-weaning and post-weaning mortality of small ruminants in tropical Africa is very high (Table 6). Several factors have been reported to affect mortality in small stock in various areas in tropical Africa. Among these are season and type of birth (Peacock, 1982), length of the previous parturition interval (Wilson, 1981), parturition number (Fall et al., 1982) and disease (Mack, 1982). All of these effects are clearly related to nutrition, health and management.
GENERAL MANAGEMENT AND NUTRITION
Small ruminant production in Africa is not developed. The fact that holdings are small seem not to give owners incentives for improved husbandry practices. In wetter areas, where arable cropping is the practice, small stock are tethered during the cropping season in an attempt to prevent crop damage (Okello and Obwolo, 1985; Adua and Ngere, 1979).
In Northern Nigeria, Adu and Ngere (1979) described a compound system practised by Hausas who are settled and therefore keep their small stock tethered in their compounds and feed them soilage in the rainy season. Otchere et al., (1985) reported that pastoralist Fulani in Giwa district of northern Nigeria allow sheep to accompany cattle for grazing but tethered their goats under shelter. These goats were fed cut-and-carry green forage in the rainy season. Similar management systems have been described by Wilson (1982, 1985). The general concensus is that, after crops have been harvested, small stock are let loose to feed on crop residues and fend for themselves. According to van Vlaenderen (1985) adult animals lost 22% of their body weight while average daily gain in lambs was 30% lower during the cropping season which spanned April to November in northern Togo. This observation is true in most heavily cropped areas and indicates that all is not well with the nutrition of small stock in these areas during the rainy season though undernutrition during the dry season had often been stressed as a limiting factor in ruminant production in tropical Africa (Otchere et al., 1977; ILCA, 1979; Meyn, 1980).
Improved animal nutrition appears to be a more critical factor in increasing small stock productivity. Native rangelands provide the cheapest source of nutrients for ruminants. It is however an accepted fact that for a greater part of the year, grasslands in the tropics do not supply sufficient nutrients to stock for greater productivity. Otchere et al., (1977) reported that West African Dwarf sheep, on the Accra Plains of Ghana, which received no supplementary feed during the dry season (December to February) lost about 15% of their body weight. Two groups of animals after the days normal grazing, got supplements made up of dried cassava peels and rice straw, respectively, each fortified with urea and molasses. Those which received rice straw lost 2g per head per head per day while the cassava peels group gained 19g per head per day and the control group lost 19g per head per day. That supplementation of grazing enhances growth rate had also been reported by van Vlaenderen (1985) and Kolff and Wilson (1985). Thus, the need for supplementation of natural forage with agro-industrial by-products cannot be overemphasized. The use of conventional by-products (e.g. oil cakes and milling byproducts) is severely limited by availability and high cost. In some instances by-products, like gagasse and molasses, have had alternative uses (fuel or alcohol distillation) rather than for stock feeding.
Many crop discards like cocoa husks and corn cobs have not found their way into stock feeding even though they have been shown to be potentially useful (Adeyanju et al.,1975; Otchere et al.,1983). Many of these crop discards are not used because production is by small scale farmers scattered over a wide area thereby making collection impractable. It must be mentioned however that there are several large plantations and or farms now in Africa on which such crop discards are allowed to rot. Such large scale farms could include fattening of small stock in their operations so as to utilise these discards.
There are at least three breweries in most tropical African countries (Nigeria has about twenty). Several tonnes of spent brewer's grains are wasted because only a few of the breweries have drying facilities. It is suggested that future breweries be required to include drying facilities so as to facilitate the use of the dried brewer's grains for stock feeding. Efficient use of such by-products for stock feeding under present conditions would call for the stratification of the system of small ruminant production. Estimates by ILCA (1979) showed that Africa potentially had agro-industrial by-products that could be used for fattening about one million small ruminants for a 90 day period each year during the 1980s.
Several factors make it difficult for Africa's agro-industrial by-products to be harnessed. In the mean time, wholesale rangeland improvement is not practicable because grazing land is communal. The majortiy of stock owners do not own land and for those who have, the farm sizes are small and grossly subsistence crop-based. An integration of forage legumes into the cropping system of small stock owners would go a long way to improve the productivity of their animals. Research along these lines has been initiated by ILCA in Nigeria and Mali (ILCA 1982) and the Small Ruminant Collaborative Research Support Programme (SR-CRSP) of the United States Agency for International Development in Kenya (SR-CRSP, 1982). Initial indicators appear very favourable, and it is therefore suggested more such experiments need to be conducted in other zones in several countries. National research institutes (both crop and livestock) should cooperate and find feasible avenues for integrating livestock and crop production. A systems approach would appear to yield relevant results and research efforts should emphasise the idenfification of factors which, when modified or eliminated, will enable small ruminant producers in tropical Africa to have control over the productivity of their animals and not under the control of ecology as is the case at the present.
Helminthiasis and ectoparasitosis are widespread in tropical Africa and both seriously affect the productivity of small ruminants. Helminthiasis is a serious problem towards the end of the rainy season while ectoparasitosis inflicts heavy damage during the rains to early dry season. Van Vlaenderen (1985) reported that deworming of adult sheep in Togo did not have any effect on weight gain or mortality. In lambs, however, deworming reduced mortality by 50% but growth was not affected. In ILCA studies in south west Nigeria, Opasina (1984) reported that ectoparasitic control in goats appeared not to result in higher growth rates.
The author has observed a condition of “lameness” in small ruminants which strikes normally at the beginning of the rainly season in norther Nigeria. Affected animals have impaired locomotion and their condition normally worsens if not controlled. Surgical intervention had invariably shown that there was an in-vagination of hairs which had formed into a cylindrical shape interdigitally. If removed and treated with tincture of iodine the animal recovered within a short time.
In West Africa, peste de petit ruminants (PPR) is endemic. Studies bu ILCA scientist in south west Nigeria (Mack, 1982) showed that dipping with gammatox against ectoparasites and annual vaccination against PPR very dramatically reduced mortality and increased small stock numbers in village flocks. It was observed that mortality among sheep and goats in the ILCA studies decreased by 75%. While death rate was reduced, offtake rate did not increase and, therefore, flock inventories rose. Cost benefit analysis demonstrated that annual vaccination against PPR was viable under south west Nigeria conditions. It is suggested that the vaccination programme would be even more viable in the pastoral and agro-pastoral regions of West Africa where holdings are larger and that it can be a part of the annual vaccinations against rinderpest in cattle.
An efficient, well-planned animal health service is a pre-requisite for increasing small ruminant production in tropical Africa. It must be stressed, however, that any improvement in animal health services must go hand in hand with an adequate improvement in the provision of feed. If this is not done, expected improvements in productivity may not be realised and could lead to further destruction of rangelands in major producing areas as a result of large increase in numbers. An improvement in the performance of small ruminants in tropical Africa would directly improve the diet and standard of living of the large number of rural smallholders.
Adeyanju, S.A., Ogutuga, D.B.A., Illori, J.O. and Adegbola, A.A. (1975).Nutr. Rep. Intl., 11:351–357.
Adu, I.F., Buvanendran, V., Taiwo, B.B.A. and S.A.S. Olorunju. (1985). In Research progress report. National Animal Production Research Institute, Shika, Zaria, Nigeria.
Adu, I.F. and Ngere, L.O. (1979). Wld. Rev. Anim. Prod. 15:51–62.
Bayer, W. (1984). Traditional small ruminant Production. Paper presented at the 2nd ILCA/NAPRI Symposium on Livestock Production in the Subhumid zone of Nigeria. 30th October – 2nd November, 1984.
Fall, A., Diop, M., Sandford, J., Wissocq, Y.J., Durkin, J. and Trail, J.C.M.(1982). Evaluation of the productivities of Djallonke sheep and N'Dama cattle at the Centre de Recherches Zootechnique, Kolda, Senegal. Research Report No. 3. ILCA, Addis Ababa, Ethiopia.
F.A.O. (1982). Production year book. F.A.O., Rome.
ILCA (1979a). Small ruminant production in the humid tropics. Systems study No. 3. ILCA, Addis Ababa, Ethiopia.
ILCA (1979b). The potential of tropical Africa in by-products for animal feeds. Bulletin No. 6. ILCA, Addis Ababa, Ethiopia.
ILCA (1982). ILCA Annual Report. Addis Ababa, Ethiopia.
Kolff, H.E. and Wilson, R.T. (1985). 16:217–230.
Mack, S. (1982). Small ruminant breed productivity in Africa. (Ed. R.M. Gatemby and J.C.M. Trail), ILCA, Addis Ababa, Ethiopia.
Matthewman, R.W. (1977).A survey of small livestock production at the village level in the derived savanna zones of south-west Nigeria. M.Sc. thesis. University of Reading. 174pp.
Meyn, K. (1980). Livestock constraints. Bulletin No. 9. ILCA, Addis Ababa, Ethiopia.
Okello, K.L. and Obwolo, M.J.(1985). Wid. Anim. Rev. 53: 27–32.
Opasina, B.A. (1984). Disease constraints on productivity of village goats in south west Nigeria. Humid zone Programme document No. 5. ILCA, Ibadan, Nigeria.
Otchere, E.O., Ahmed, H.U., Adesipe, Y.M., Kallah, M.S., Mzamane, N. and others, (1985). Livestock production among pastoralists in Giwa District, Kaduna State, Nigeria. Unpublished mimeo. Livestock Systems Research Project, NAPRI, Shika, Zaria, Nigeria.
Otchere, E.O., Dadzie, C.B.M., Ayebo, D.A. and Erbynn, K.G. (1977).Ghana J. Agric. Sci. 10:61–66.
Otchere, E.O., Musah, I.A. and Bafi-Yeboa, M. (1983). Trop. Anim. Prod. 8: 33–38.
Otchere, E.O. and Nimo, M.C. (1976). Ghana J. Agric. Sci., 9: 57–58.
Peacock, C.P.(1982). In Documents prepared for the Programme Committee. ILCA, Nairobi, Kenya.
Peacock, C.P.(1983).A rapid appraisal of goat and sheep flock demography in East and West Africa. Working document No. 28. ILCA, Nairobi, Kenya.
Sacker, G.D. and Trail, J.C.M.(1966). Trop. Agric. (Trin.) 43: 43–51.
SR-CRSP (1982). Proceedings of the Small Ruminant-CRSP workshop. March 15th, 1982. Nairobi, Kenya.
Velez-Nauer, M., Carew, B.A.R., Mosi, A.K., Opasina, B.A. and Hayward, A. (1982). In Proc. Int. Conf. on goat production and disease. p.356. Tucson, Arixona, U.S.A. Jan. 10–15,1982.
Vohradsky, F. and Sada, I. (1973). Sb. Vys. Sk. Zemed. Praze Provozne Ekon. Fak. Cesk. Budejocicich Rada Biol. 6. pp.161.
Williamson, G. and Payne, W.J.A. (1978). An introduction to animal husbandry in the tropics. The English Language Book Society and Longmans, London.
Wilson, R.T. (1976).Trop. Anim. Hlth. Pro. 8: 221–232.
Wilson, R.T. (1981).In Systems research in the arid zones of Mali-Initial results. Systems Study No. 5. ILCA, Addis Ababa, Ethiopia.
Wilson, R.T. (1982). Small ruminant breed productivity in Africa. (Ed. R.M. Gatemby and J.C.M. Trail ILCA, Addis Ababa, Ethiopia.
Wilson, R.T. (1985). Wid. Anim. Rev. 53: 8–14.
TABLE 1. Importance of sheep and goats in Africa.
|Parameter||World||Africa||Africa as % of world|
|Tatal population of small ruminants||1602.3m||331.2m||20.7|
|Meat production (metric tonnes)|
|Total milk from small ruminants (metric tonnes)|
Source: FAO (1982)
TABLE 2. Pattern of ownership and flock sizes or small ruminants in the humid zone of south west Nigeria.
|Forest zone||Derived savanna zone|
|Percentage of farmers owning small ruminants||73||20|
|Mean flock size:|
Source: Mosi et al., (1982) cited by Wilson, (1982).
TABLE 3. Pattern of ownership and flock size for small ruminants among agro-pastoralists in Giwa, Kaduna State in the subhumid zone of Nigeria.
|Respondents||63||%||Mean flock size|
|Owned sheep only||10||15.9||12.6|
|Owned goats only||8||12.7||13.0|
|Owned both sheep and goats||34||54.0||30.5|
|Owned small stock||52||82.6||24.3|
|Owned no small stock||11||17.5||-|
|*Mean flock size (all sheep) Range:2–50||44||11.7|
|*Mean flock size (all goats) Range: 3–57||42||18.0|
* For owners keeping small stock, i.e. nil holdings excluded.
Source: Otchere et al. (185)
TABLE 4. Holding sizes of small ruminants in agro-pastoral and pastoral societies in Kenya, Tchad and central Mali.
|Masai||Karapokot||Zioud||Salamat||Irrigated rice||Rainfed millet|
Source: Wilson, 1982.
TABLE 5. Flock structures in different zones of tropical Africa.
|Country||Breed||% Total males||% Total females||% Breeding females||Source|
|Kenya||Masai sheep||29.4||70.6||54.0||Peacock (1983)|
|Kenya||Masai goats||33.7*||66.3||56.5||Peacock (1983|
|Nigeria||Red Sokoto goats||21.4||78.6||56.9||Otchere et al. (1985)|
|Nigeria||Yankasa sheep||22.4||77.6||54.2||Otchere et al. (1985)|
|Mali||Native sheep Agro-pastoral sedentary||23.5||75.5||62.0||Wilson (1985)|
|Mali||Native goats pastoral transhumant||21.0||79.0||56.5||Peacock (1983)|
|Sudan||Native goats||23.6||76.4||51.2||Wilson (1976)|
|Ethiopia (Afar)||Native goats||3.3+||96.7||65.5||Wilson (1982)|
*Castrates = 24.8%
+Almost all males killed a few hours after birth.
TABLE 6. Some reproductive parameters and pre-weaning mortality in small ruminants.
|Country||Breed/Species||Age 1st parturition (mths)||Parturition interval (days)||Ave. litter size||% multiple births||Pre-weaning mortality %||Source|
|Sudan||Native goats||10||238||1.34||52||16||Wilson (1976)|
|Shana||W.Afr. dwarf goats||12||266||1.87||68||21||Otchere & Nimo (1976); Vohradsky & Sada (1973)|
|Mali||Native goats||16||250||1.20||23||35||Wilson (1982)|
|Mali||Native sheep||16||257||1.05||5||30||Wilson (1982)|
|Kenya||Native goats||15||289||N.R||18||N.R||Wilson (1982)|
|Kenya||Masai sheep||18||344||1.02||N.R||N.R||Wilson (1982)|
|Uganda||Mubende goats||19||297||N.R||32||46||Sacker & Trail (1966)|
|Nigeria||Sokota red goats||19||N.R||1.34||32||35||Otchere et al. (1985)|
|Nigeria||W.Afr. dwarf sheep||18||279||1.30||N.R||N.R||Mack (1982)|
|Nigeria||Yankasa sheep||19||227||1.04||3||39||Otchere et al. (1985);Adu et al. (1985)|
|Nigeria||W.Afr. dwarf goats||18||278||1.60||70||15||Matthewman (1977) Veleznauer et al. (1982)|
|Senegal||Djallonke sheep||19||307||1.12||12||33||Fall et al. (1982)|
|Tchad||Fellata sheep||15||N.R.||1.07||N.R||N.R||Wilson (1982)|
N.R.= Not reported