Synthèse bibliographique sur les zones agro-climatiques, les ressources fourragères, les caractéristiques des systèmes d’élevage et la production de viande et de lait au Tchad

In Chad, one of the main obstacles to the development of ruminant breeding is the feeding of herds. Improving the food situation of livestock requires the adaptation of livestock systems, the available food resources; the more efficient and widespread use of gricultural by-products and agro-industrial co products for feeding ruminants. The agro-climate versity which results from the extent of the Chadian territory determines the specificity of pastoral resources and livestock production systems. The Saharian zone, the Sahelian pastoral zone, the Sahelian agro-pastoral zone and the Sudanian zone are the four agro-climate zones in Tchad. Livestock systems are diversified in relation to the climate, the socio economic, cultural and religious particularities of the regions. In any case, the exclusively extensive system (transhumant, nomadic) and the semi-intensive system (sedentary) are the two main distinguished categories. The breeding of domestic ruminants (cattle, sheep, goats) occupies an important place in the country's economy. The ruminant herd is unevenly distributed and is concentrated more in the center of the country. Beef is the most consumed and its production reached 475,447 tons in 2021. The pastoral areas of Chad offer a great diversity of forage resources. In the southern Sudanian
zone, the annual biomass production recorded varies between 7 and 8 t of DM/ha and around thirty forage species have been recorded on natural rangelands. The dominant biological types were grasses. Currently in Chad, purely fodder crops are almost non-existent. However, some agro-breeders take advantage of their sedentary lifestyle to practise the production of cereal grasses. They reserve all or a large part of the harvest residues for animal feed. The pedoclimatic conditions for producing cultivated fodder are well met in Chad. The main forage crops tested in the different research centers are indicated. To increase the productivity of ruminants, the sedentarization of ruminant herds and valorization in the form of multi-nutritional blocks of agricultural by-products and agro-industrial co-products in the diet of ruminants in Chad are the two interdependent strategies proposed in the literature review.