|SPORE Bulletin of the CTA No. 08 - January 1987 (CTA - Technical Centre for Agricultural and Rural Cooperation, 1987)|
Poultry farming may provide an answer to the problem of nourishing the rapidly increasing populations in developing countries, especially those with mushrooming urban areas. To help meet the food needs of city dwellers, battery farms modelled on those in industrialized countries have been developed over the last twenty years with considerable success. Poultry farming in rural areas, however, remains highly traditional and has hardly been improved despite the fact that it still provides the bulk of production.
Although most farming households in Africa generally keep a few chickens, poultry breeding remains for them only a secondary activity. It simply enables some ready cash to be brought in when needed by selling off a little of the capital that such birds represent for most farmers. Of more importance is the social significance of such flocks, given the fact that chickens are traditionally used as presents or tokens of exchange and make up the main dish that is served during certain festivities.
Poultry consumption in rural areas is however, generally limited to such festive occasions and is estimated to be no more than one or two chickens per person per year. As for eggs, their consumption is severely limited by food habits and certain taboos.
Under these conditions, poultry farming remains a supplementary source of income and thus must not incur any additional costs. It is almost like having a flock of wild birds as there are no breeding costs and they maintain themselves on readily available resources.
These free-range chickens feed on kitchen waste, crop leftovers, grain residues, insects and some grass in the rainy season. Farmers occasionally trap termites for young chickens, but it is extremely rare to feed them grain. The birds are left to roam during the day, either within or around the yard. At night, they are kept inside wattle or straw roosts which are often very small, badly aired and rarely cleaned or repaired. Birds of different species and ages are bunched together indiscriminately under conditions favouring the spread of diseases.
Furthermore, eggs are hatched without supervision and are seldom collected.
Under these conditions poultry farmers suffer high losses. The birds are attacked by predators, eggs get broken or lost, and chicks often die before they are two months old. Their numbers are regularly reduced by parasites and respiratory diseases. Viral infections such as Newcastle disease are particularly common during the dry season. Their numbers also fluctuate considerably, being higher during the rainy season when climatic conditions are more favourable, and lower during the dry season when mortality is higher and more of them are sold. Most of these flocks consist of native chickens which have long interbred with European breeds. They are generally known as 'African chickens','running chickens' or 'country chickens'. They are usually small and of various colours, and they weigh approximately one kilo when they are sold at the age of six to eight months. A hen lays between 50 and 90 eggs a year. Although such production is relatively low, these birds have the advantage of being very sturdy, resistant to tough climatic conditions and good breeders. Apart from chickens, one also finds guinea fowl that have been domesticated from the various wild strains of the savannah regions. Their genetic adaptation to the local environment is very important under such farming conditions.
In order to improve productivity attempts have been made to replace local cocks with improved western breeds, such as Rhode Island or Plymouth Rock. Such initiatives, which began in French-speaking Africa over a decade ago, have not always lived up to expectations. It has not been easy to reach all poultry farmers and thus to eliminate all the local strains of cocks, especially as farmers often prefer to keep birds of different types and colours to meet particular social requirements. In fact, genetic improvement alone will not bring about a substantial increase in production. It must be combined with effective sanitation measures and improvements in feeding and health care. Closer supervision, especially during and after incubation, would also cut losses. The use of better and regularly cleaned hen roosts, the isolation or elimination of sick birds, and the quarantine of new arrivals, would also considerably reduce the incidence of disease.
Some NGOs are thus promoting more appropriate roost designs that are easy to build with local materials. Regular vaccination is also necessary to fight epidemics which can destroy entire flocks almost overnight.
If farmers are going to increase their poultry production significantly, they must drastically change their feeding methods. This will require educational campaigns to convince them that it is in their interest to feed their chickens. But this is only possible if their other operations provide enough surplus grain or if they can afford to buy commercial feed. This is a feasible proposition as such chickens generally sell well, either directly on local markets or to middlemen who buy on behalf of urban merchants. In fact, free-range chickens are highly valued by urban consumers who prefer them for traditional, stewed dishes. In Dakar, for example, demand often exceeds supply and free-range chickens fetch a higher price than battery chickens.
But if poultry farming is to be profitable, transportation methods will have to be improved. Live hens in exposed cages stacked on the roofs of taxis, or hanging by their feet from bicycles or motorcycles, are often the worse for wear, if not dead, on arrival. Those that do survive must then face the poor handling conditions of the markets.
Nevertheless, local breeds still account for the bulk of poultry production in Africa, varying from 70 % to 90 % depending on the region.
Production in large, modern battery farms is now increasing rapidly in many countries, notably in Cote d'lvoire and Cameroon. This sharp growth in battery farming, supported by governments anxious to supply urban areas and to reduce meat shortages, has been stimulated by numerous financial incentives.
Battery chickens differ from local breeds not only in taste, but even more so in their cultural requirements which are similar to those used in Europe.
Such intensive poultry farming is most often located on the outskirts of large cities. In Cote d'lvoire, for example, 90 % of this type of farming is concentrated around Abidjan with practically none in rural areas. The smallest of these battery farms have only a few hundred birds, use improved breeds and buy part of their feed. They are owned by city dwellers, merchants or state employees who use them to supplement their incomes. Intensive poultry farms are hardly ever owned by small farmers, except where charitable organizations or NGOs have provided financial assistance. Since few of the operators have been specifically trained for the job, feeding and sanitation standards are often DOor.
Huge battery farms also exist, housing thousands or tens of thousands of birds. These are sometimes known as 'chicken cathedrals' and have been set up by large European firms. The largest of these operate as completely integrated concerns with the same company taking care of everything from hatching to sale, including feed and medecine supply slaughtering and marketing. Others are only partially integrated feed stuff, chicks and training are provided, but the farmer is in charge of everything else, including market~ng.
All of these farms use improved genetic strains. Chicks are provided from breeds which have been especially selected for egg or meat production. Other commercial criteria, often of a psychological nature, such as the colour of the eggs or feet, are also taken into consideration. Rhode Island hens, which produce coloured eggs, are highly valued in West African countries.
A more important factor is the use of breeds that are adapted to both the climate and the type of feed provided. Those that come from the few major world breeders often do not have characteristics appropriate to tropical environments. Large goodlaying hens, for example, suffer from the heat. Much better are small hens, such as the 'Vedette' with its dwarfism gene, or bare neck hens, which adapt more easily to high temperatures. It is also advisable to choose birds with a sound appetite that will ensure an adequate food intake even when hot weather reduces the desire to eat.
Although the use of incubators has spread recently in most countries, there are often still not enough to be able to provide battery farms with adequate supplies of day-old chicks. They thus have to be flown in from abroad which is very expensive and risky. Those chicks that do survive the stressful journey often arrive in such a state that their initial growth is severly compromized.
These battery farms use feed which is prepared locally but consists of a large proportion of imported ingredients to which locally available raw materials are added wherever possible. The use of soya and maize cakes, minerals and vitamins from Europe or the United States results in a considerable drain on foreign reserves and problems of storage and supply interruptions. Imported raw materials account for nearly 50 % of the cost of a chicken. The same is true for medicines, which are rarely produced entirely in the country.
On the other hand, local resources are often under-exploited and little work has been done on how to make better use of them or how to ensure a higher and more consistent quality. Many products nevertheless deserve to be more widely used: cassava, molasses, rice by-products, copra and palm cakes and, of course, cotton or ground-nut cakes Many of these products go to waste, yet they could, to a large extent, replace imported products and increase the much needed self-sufficiency in feed stocks.
African battery poultry farming thus remains highly dependent on foreign supplies and technical expertise. The building designs used are often copied from European models which are obviously not always appropriate for hot countries. It would be preferable to construct buildings which are better ventilated, have better heat protection, more drinking troughs and less densely-populated hen houses. Although African battery farms are considerably more productive than poultry farming in the countryside, they do not achieve the levels of productivity of European chicken factories as the birds fatten less quickly and lay fewer and smaller eggs. Heat and the rapid spread of microbial infections in humid regions are the main reasons for this. Productivity would be improved if battery farms were located in cooler areas such as uplands.
In spite of some negative results, intensive poultry farming has developed spectacularly over the last decade as it remains the only way of rapidly meeting demand. However, prices are still high for the consumer and the commercial market, serving essentially Europeans and wellto-do Africans, is likely to become saturated unless prices come down. Moreover frozen chicken imported directly from industrialized countries is beginning to make considerable inroads on this same rich man's market. These products, heavily subsidized by the exporting countries, are often less expensive in ACP countries than locally-produced chicken.
There has also been an increase in the production and consumption of eggs but their market does not extend beyond urban areas.
Although modern poultry farming is capable of providing high protein food for towns, it is still too expensive and dependent on external factors.
Applied research on the food value of local raw materials and the training of competent personnel are needed if self-sufficiency is to be ensured. At some time, traditional poultry farming, relying solely on local resources, is a potential source of considerable production. But it has so far been underestimated. increased information and extension programmes, improved sanitation, and better marketing and distribution networks would enable traditional poultry farming to make a more significant contribution to both the village and the national economy Such chicken production will never be able to meet urban needs, but the towns can become a real market for small producers who could obtain considerable extra income without competing with battery farms.
What then is the solution ? Should one increase production in order to develop the market ? Or develop the market in order to increase production ? It really isn't a question of which comes first, the chicken or the egg, but rather of the willingness to ensure that poultry farming is given a major role in projects and aid.
- IEMVT (1983). Manuel d'aviculture tropical - IEMVT, Ministere des Relations exterieures-Cooperation et Developpement. Paris.
- Saunders M. J. (1984). Aviculture traditionnelle en Haute Volta - Assoc,ation Frangaise des Volontaires du Progres Projet developpement aviculture villageoise Ouagadougou.
- Forssido, T. (1986). Studies on the meat production potential of some local strains of chickens in Ethiopia. Ph.D. thesis, Scientific Centre. Tropeninstitut. Justus Liebig Universitaet. Giessen. Germany.
Leucaena's promising future
Leucaena leucocephala offers marvels: high production of fuelwood, fodder and fertilizer resources. But below this beauty lies a serpent: it contains a substance which is harmful to animals. First experiments show that this toxicity can be overcome.
Leucaena has exceptional merits: a rapid growth rate, unrivalled wood and forage production, and a capacity to fertilize the soil where it grows. But there are some drawbacks: the leaves of leucaena contain 'mimosine', an amino acid that is toxic to animals. This has long prevented the use of leucaena as fodder, but considerable progress is about to be made towards solving this problem thus opening the way for leucaena to play a major role in the tropics.
Oaxaca is the name of the Mexican state and city that the Zapotec, an affluent society of the mid 16th century, called 'Uaxin'. The Spanish conquistadors changed it into Oaxaca or 'place where leucaena grows'. Leucaena has since spread far and wide and is still present on its native soil not only in the names of towns and places, but also physically in a great number of varieties. The first leucaena variety that went overseas and spread in tropical areas was the common variety which is a relatively small tree about five meters high, of vigourous and sturdy growth, and which produces seed freely. It first arrived in the Philippines on Spanish ships which left Acapulco exporting mainly pepper, vanilla, cocoa and coffee, but also carrying leucaena leaves as fodder for animals on board. Leucaena seeds spread and germinate all over the islands, demonstrating the qualities of the tree to the local population. Thus the leucaena tree followed the progress of the Spanish conquests. In the 19th century the tree reached the Dutch East Indies, Southeast Asia and finally West Africa
But until recently only Leucaena leucocephala, the so-called 'common' variety, was well-known. Research carried out chiefly in Hawaii during the 1 960's has examined over 800 varieties, divided into three main groups: common varietal type, Giant leucaena types and Peruvian types.
The 'common' types are principally used by farmers for soil fertilization. Their yield of timber and forage is too low to allow a comparison with other types. Moreover, their sturdiness and resistance apparently also have disadvantages: the plant can turn what is designed to be a controlled cultivation into an overwhelming invasion.
The second group includes trees of about twenty meters height, hence the name: 'Giant leucaena'. These types are much appreciated for the considerable quantity of timber they produce. Large plantations of Giant leucaena trees already exist in tropical areas, especially in India, Thailand and the Philippines.
The third group contains the so-called Peruvian types. These trees have a height, of around ten metres, produce many low branches and thus make excellent forage trees.
The various varieties of leucaena small or giant, whether with good fertilizer forage or wood production qualities, all share common characteristics. Belonging to the family of leguminous plants, leucaena possesses the ability to transform atmospheric nitrogen contained in the soil into components that that can be assimilated by the plant. The Rhizobium bacteria, which are found in the soil, penetrate young roots and multiply around the nodules, enabling leucaena to absorb nitrogen. Thus even on the most marginal soil leucaena grows satisfactorily without nitrogenous fertilizer
Leucaena also uses many other resources in its environment, assisted by mycorrhizae, the small soil fungi which can increase the ability of plants to assimilate minerals from the soil. From a physical point of view, nature has been generous with leucaena, in that it endowed it with tap roots which can pierce through layers of hard clay sometimes reaching a depth of two metres in less than a year. The efficiency of its root system enables the tree to absorb water and minerals at depths which are rarely accessible to other plants. Leucaena will not perish even in dry seasons lasting eight or ten months, although its growth may be severely curtailed. But growth will be resumed with the first rainfall. In its native region, Oaxaca in Mexico, growth is slow as severe droughts often destroy practically all plant life. except leucaena
It must be remembered, however that to benefit from the production potential of this plant, certain climatic and soil criteria must to be fulfilled.
Although leucaena may survive on marginal soils it will perform poorly, if at all, on soils that are either acid or rich in alumina which is unfortunately often the case in the Sahel. On the other hand, leucaena will yield well on fresh, deep soils whether neutral or alkaline, provided that the annual rainfall is between 800 and 2000 mm and that temperatures do not drop below freezing point.
Giant leucaena holds two records in timber production. It is the best yearly timber producer, averaging an annual 45 tonnes of dry matter per hectare, and up to 80 tonnes under particularly favourable conditions. This is three to ten times more than the average rate of biomass production.
It is also the fastest growing tree and can grow 18 m in four to eight years.
Other advantages are that it can be planted very densely, more than 10,000 trees per hectare, given adequate soil and climatic conditions. In Taiwan 10,000 hectares of leucaena have been planted for paper, rayon and timber industries.
This tree's rapid growth and the quality of its timber make it an ideal species for profitable and multiple use. In the Philippines, where the authorities are currently setting up an extensive rural electricity network, leucacea will play a major role in providing energy. The Philippine government is counting on leucaena wood to yield up to 4,640 kcal/kg. One hectare planted with leucaena provides the equivalent of 25 to 30 barrels of oil per annum.
Nevertheless, researchers from the French Centre for Tropical Forestry Techniques (CTFT) stress that leucaena trees cannot, contrary to what has often been suggested, be counted on to remedy the problem of Africa's desertification.
The dry ferruginous or lateritic soil of the Sahel is not favourable for leucaena plantations. But leucaena appears promising for small scale projects of village reforestation in well-selected environments.
Leucaena trees are useful not only for industrial and energy production, but also for agriculture. The leucaena is much sought after in many tropical regions for its considerable soil regenerating and fertilizing ability. Litter falling from the trees enriches the soil with large quantities of nitrogen and minerals absorbed by the tree from considerable depths. Studies carried out in Hawaii show that leucaena leaves collected from one hectare contained 44 kg of phosphorus and 187 kg of potassium, as well as calcium and numerous trace elements.
It is for this reason that farmers in Hawaii and the Philippines plant leucaena along with grains, mainly maize. A plot of maize, which only yielded 0.66 t/ha/yr doubled its yield in two vears after a hedge of leucaena was planted two or three metres from the crop.
On the African continent, in Nigeria for example, leucaena twigs and leaves are being used as a nitrogenous green manure. Associated crops of maize/yam/rice/leucaena hedges have been planted without any additional fertilizer input and in two years yields amounted to three to five tonnes per hectare, i.e. approximately four times the average African maize yield.
Animals profit from leucaena leaves which they prefer to those of other forage crops. Veterinarians appreciate their high nutritional value: they are rich in protein, which makes up 25 % to 30 % of leucaena dry matter, with a well-balanced amino-acid, vitamin and mineral content.
The Peruvian leucaena types, like the timber types, is not only remarkable for the quality of their production but also for their abundant biomass: in a well-maintained and regularly pruned plantation, production can reach 6 to 18 t/ha/yr of dry matter (leaves and twigs). Lucerne, often regarded as the best forage plant, only produces 8 to 9 t. In dry areas, lucerne only produces 2 to 3 tonnes whereas leucaena remains unaffected by drought as long as its deep roots can reach qroundwater.
Many farmers in the tropics have planted Peruvian types of Leucaena at a density of 75,000 to 140,000 plants per hectare for use as forage. More common still is the introduction of leucaena for forage purposes in intensive crop plantations, to take advantage of the fact that leucaena trees have a beneficial effect on the surrounding crops. Others have planted it as hedges along roads or on waste land.
Animal weights increase from 300 to 400 kg/ha/yr to 800 kg under optimal conditions. The highest gains can be obtained when leucaena is fed in combination with other forage plants, but the development of leucaena as a forage plant has been undermined by the presence of mimosine in its leaves.
This amino-acid can be toxic for certain animals whose digestive system transforms it into DHP (dihydroxypyridine) which affects the thyroid gland. Observers in Australia, Papua New Guinea, and many African countries have found that a diet containing more than 30 % leucaena leaves represents a severe health hazard for cattle resulting in loss of weight, loss of hair, reduced growth, sluggishness and disorders of the reproduction system.
Yet elsewhere, in Indonesia, India and Hawaii, animals grow and breed normally while eating a diet entirely composed of leucaena.
Australian researchers have found that this phenomenon is due neither to the particular type of leucaena, nor to particular genetic characteristics to be found among cattle of different countries but to the presence in their rumens of a bacterium that breaks down the toxic DHP compound.
Research is currently focusing on transferring this bacterium to animals who do not already carry it. The required strain has been isolated in vitro end animals have been inoculated with these bacterial isolates. Inoculation is easy as it can be done naturally within a herd by exposing the animals to saliva left on leaves. The International Livestock Centre for Africa (ILCA) has carried out tests with promising results that indicate that the problem of toxicity may soon be overcome.
Another solution to the mimosine problem would be to produce leucaena hybrids with amino-acid free leaves. Australian researchers are currently working in this direction, trying to create a hybrid using two species of plants: Leucaena pulverulenta, which has a low, safe level of mimosine that animals can tolerate but poor leaf production and Leucaena leucocephala. The combination of their characteristics might produce a promising hybrid. Results obtained by researchers indicate that their efforts are meeting with success. Once the toxicity problem of leucaena is overcome, it may turn out to have more hidden advantages than hitherto suspected.
Until recently, of the vast array of leucaena species, only Leucaena leucocephala has been the subject of major research and experiments. But forestry experts and researchers are now studying other species more intensively. They are discovering that leucaena species perform well on a wider range of soils than had previously been thought.
Leucaena diversifolia and Leucaena shannoni grow on soils that are too acid for Leucaena leucocephala. Leucaena paverulenta is remarkable for its drought tolerance, its adaptability to low temperatures, and its high-quality timber production Leucaena diversifolia and Leucaena esculenta are best suited for high altitudes in tropical areas Is this little Mexican tree, that promises so much and asks for so little, going to turn out to be another of those miracle plants which have been heralded over the past few years ? Unlike the others, which never left the boundaries of research plots, leucaena varieties are already producing satisfactory results in rural areas all over the world.
Research will be able to accelerate its distribution and further improve its production. It should not be too difficult to convince farmers of its usefulna.c.c
- National Academy (1984) Leucaena: Promising Forage and Tree Crop for the Tropics'. National Academy Press Washington D.C.. U.S A. - Dayadee J. (1984).'lnvestigations on the feeding of sugar cane products and their mode of presentation with leucaena in two breeds of goats in Mauritius'. Scientific Centre. Tropeninstitut, Justus Liebig Universitaet. Giessen. Germany 157 pp.
- G.R.E.T (1986) Le Leucaena: mirage ou miracle'. Reseaux Bulletin du Groupe de Recherche et d Echanges Technologiques G. R. E T. Paris.
- Haque, I., Jutz, S, Neate, P.J.H. (1986). 'Potentials of forage legumes in farming systems of sub-Saharan Africa'. Proceedings of a workshop held at ILCA, Addis Ababa, 16-19 September 1985, ILCA, 569 PP