Further Studies on the Nutritive Value of Opaque-2 Corn for the Chick

CROMWELL et al. (1967, 1968), working with young chicks, reported only slight differences in growth rate and feed conversion by the isonitrogenous substitution of opaque-2 corn for normal corn in corn-soybean meal diets of suboptimal protein content. However, when a deficiency of the first limiting amino acid in this type of diet, methionine, was corrected by supplementation, significantly better gains and feed conversions were observed with opaque-2 corn as compared with normal corn. Since supplementation of normal corn diets with lysine up to the level in opaque-2 corn diets resulted in equal performance, it was concluded that the beneficial effects of opaque-2 over normal corn is mediated solely through the higher lysine content of opaque-2 corn. Analyses of plasma amino acids revealed higher lysine levels in chicks fed opaque-2 corn as compared with chicks fed normal corn. In the current studies, the nutritive value of opaque-2 and high protein opaque-2…