Utilization of Proteins by the Growing Chick

1. There is a marked difference in the nutritive value of the various protein-contributing concentrates when used to supplement a corn-wheat basal ration which has been made complete for known vitamin and mineral essentials. 2. There is a great difference in the biological value even of animal protein concentrates. 3. Soybean meal produced a better growth rate than any of the other plant concentrates used. Cottonseed meal proved to have a greater growth-promoting value than did linseed oil meal. 4. The supplementing values of protein concentrates, one to another, is not quite as evident as one would expect if the commonly stated theory of protein utilization is accepted without question.