Feed is the most important input in livestock production, and its adequate supply (quantity and quality) throughout the year is an essential prerequisite for any substantial and sustained expansion in livestock output. In Sub-Saharan Africa, animals depend almost exclusively on natural pasture and crop residues with great seasonal variations in quantity and quality. Not only has the rate of growth in livestock output declined over the last two decades, but also the percentage of output growth attributable to productivity per animal rather than to more animals has also decreased (Anteneh, 1984).
Among the major reasons for this low performance, poor animal nutrition is paramount. Feed resources are inadequate in both quantity and quality, with a ration which does not enable African breeds to reach their full genetic potential for meat or milk production. Although it is widely accepted that African breeds are generally of low genetic potential, available evidence indicates that their productivity has been suppressed significantly by inadequate nutrition (Olaloku, 1976; ILCA, 1979; Pullan and Grindle, 1980).
While there is a general consensus that the lack of reliable and adequate feed resources imposes a major technical constraint on increasing livestock output in Sub-Saharan Africa, considerable quantities of agricultural byproducts, particularly molasses, oilcakes and fishmeal are being exported or wasted. Agricultural byproducts are important sources of high-energy or high-protein feedstuffs and therefore can make a substantial contribution to feed supplies, particularly during the dry season when crop residues and natural pasture are scarce. However, their use for animal feeding in Sub-Saharan Africa remains very limited owing to export policies aimed at earning foreign exchange, poor internal transport infrastructure coupled with the great distances involved, the lack of convenient and reliable suppliers, and unfavourable price ratios.
Many experiments in Sub-Saharan Africa, show that some form of mixed ration (roughage, oilcakes, and molasses) could increase the productivity of local breeds. This suggests that the introduction of exotic breeds is not a prerequisite for increasing livestock output in Sub-Saharan Africa. Therefore, improved feeding strategies which include agro-byproducts together with crop residues and natural pasture should allow greater technical efficiency to be achieved in the Sub-Saharan Africa's livestock sector. The purpose of this paper is to review macro data on production and utilization of major agro-byproducts in Sub-Saharan Africa and to evaluate their feeding potential in relation to their nutritive values for cattle feeding systems in the sub-continent. Of the major agricultural byproducts, particular attention is focused on those involved in international trade. These are molasses, groundnut cake, cottonseed cake, sunflower seed cake, palm kernel cake, and fishmeal. The term 'byproduct' will usually refer to molasses, oilcakes, and fishmeal. The analysis of past trends in byproducts is based on FAO computer data base and covered the period between 1961 and 19841.
1. The choice of this period is dictated solely by the availability of data. Data after 1984 were not available at the time this paper was written.
