The relative values of cereal proteins for chick growth.

Many studies have been undertaken in the past half century to assess the relative values, for production, of the proteins in those cereals most commonly used in the feeding of non-ruminant animals. Cereals are usually regarded in the first place as a major source of energy, but they incidentally supply from oneto two-thirds or more of the dietary protein requirement. For poultry the proportion of protein provided by the cereal part of the diet is about one-third when the bird is young and increases to about two-thirds in the adult bird as the need for protein in the diet is reduced. Both the species of animal used to assess the worth of cereal protein and the manner in which the protein has been administered have varied. In some tests the cereals have been given alone and in others with some common basal mixture. On several occasions one or other of the cereal proteins has been shown to be superior to the others tested, either in digestibility or in utilization of the digested nitrogen or in both, but the general impression has remained that there is no appreciable difference in overall protein value. One would expect, however, from tables of amino acid composition such as those of de Man & Zwiep (1955) , that oat protein