The Use of Cassava, Sweet Potato and Cocoyam, and Their By-Products by Non - Ruminants

As the search for alternative sources of energy for non ruminants continues, this review was undertaken to examine the potential value of cassava (Manihot utilissima Pohl.), sweet potato (Ipomea batatas Poir.), cocoyam (Xanthosoma sagittifolium Schott.) and their by-products as dietary supplements for non ruminants. Studies on these roots and tubers showed that, on a dry-weight basis, contained 2.0 - 7.9% crude protein, 0.3 - 3.1% crude fib re and 72.4 - 77.9% starch. The practical use of these roots and tubers in non ruminant feeds is generally low. Th is level of utilizat ion is attributed to the low protein and dry matter and the potentially to xic cyanogenic glycosides in fresh cassava and irritating substance in cocoyam. Processing techniques such as fermentation, soaking, boiling, ensiling and sun-drying are adopted to remove the deleterious substances, and effects on animals. The co mparable performance of pigs and poultry fed vary ing levels of roots and tubers and their by-products with those maintained on maize showed that they can be used as substitutes in non-ru minants diets at certain levels without detrimental effects. To achieve increase in the use of these root crops and their by-products for maize replacement in intensive non-ruminant production systems, adequate protein supplementation and proper processing are essential.