Some Nigerian Protein Concentrates as Foods and Feeds

Abstract

THE nutrients, amino acid composition and protein quality of a range of Nigerian foods and feeds have been studied in chemical and biological tests with pigs and rats. Lysine, methionine, tryptophan and, to a lesser extent, threonine, were the amino acids present in the least amounts in most of the concentrates. Apparent and true digestibility of the concentrates were high except for palm kernel meal (PKM), African locust bean (ALB), and cashewnut scrap meal (CSM). All the animal protein concentrates showed good nutritional qualities except blood meal (BM), which, despite its high lysine content, showed very poor nutritional values and supported no gain in pigs or rats, probably due to its low methionine - cystine and tryptophan content, coupled with a possible isoleucine-leucine antagonism. Among the plant proteins, ALB showed particularly low values, while cashewnut good grade meal (CM) was found to be superior to soyabean meal (SM). The cashewnut scrap kernel meal (CSM) was inferior to the good grade meal. When evaluated at a critical protein level with growing pigs, it was found to be superior to groundnut meal. In practical type diets for fattening pigs, CSM diets were superior to the groundnut meal (GNM) diets, in terms of growth and efficiency of feed utilization. The PKM, despite its apparent balance of amino acids showed poor nutritional values for the rat. In a test with practical type diets, pigs on PKM grew at a highly significantly slower rate and had highly significantly poorer feed and protein efficiency ratios than the pigs on other diets. In another trial involving supplementation of PKM diets with either GNM, fishmeal (FM), BM or milk powder (MP), pigs on the PKM diet supplemented with 10% GNM, had a significantly slower rate of gain and efficiency of feed conversion ratio than those on other diets containing lower quantities of PKM supplemented with other protein concentrates. Supplementation of PKM diets with FM and BM gave significantly better results than supplementation with GNM or MP.