COMPARISON OF NIGERIAN YELLOW CORN, GUINEA CORN (SORGHUM) AND PEANUT MEAL (GROUNDNUT CAKE) WITH CANADIAN CORN AND SOYBEAN MEAL

Abstract

Three Nigerian foodstuffs, yellow corn (maize) C(Nig), guinea corn (sorghum) GC, and peanut meal (groundnut cake) PNM were evaluated chemically and biologically in comparison with Canadian yellow corn C(Can) and Canadian soybean meal SBM. Treatments consisted of seven isocaloric (3,600 kcal digestible energy/kg) diets based on combinations of the cereals and protein supplements upon which were superimposed three (20, 16 and 12%) protein levels. Diets were fed to weanling Sprague-Dawley rats for an experimental period of 4 wk. Chemical analyses revealed expected differences in crude protein, fat and amino acids between PNM and SBM. Other than in arginine and phenylalanine, PNM contained fewer essential amino acids than SBM. PNM-supplemented diets resulted in more carcass fat and less carcass lean than SBM-supplemented ones. Although there were no obvious differences in the protein and amino acid composition of the three cereals, there were interactions between these energy sources and the protein supplements. SBM gave its best performance with GC and PNM gave its best performance with C(Can). Supplementation of C(Can)–PNM diet with DL-methionine and L-lysine did not significantly improve gains. Dietary protein level showed an inverse relationship (P < 0.01) to protein and energy digestibilities expressed as percentages, although daily N retention was positively related to dietary protein level. Liveweight gain and empty body weight gain did not give equivalent relative performance to that of dry matter empty body weight gain.