Effect of Dietary Protein Level on the Methionine-Energy Relationship in Broiler Diets

Abstract

IN THEIR studies with methionine-deficient broiler diets which contained 20 to 22% protein, Baldini and Rosenberg (1955) observed that the methionine requirement, expressed as percent of diet, increased as the energy content of the diet increased. It was predicted that this principle of the energy-dependence of amino acid needs would apply to all essential amino acids and for most animals. In the meantime this has been shown to be true for the lysine requirement of rats (Rosenberg and Culik, 1955) and for the methionine requirement of the turkey poult (unpublished).In view of the realization that the energy content of the diet has such a pronounced effect on amino acid requirements it became desirable to reinvestigate several other phases of amino acid utilization. In this communication we report some results of our studies on the effect which a change in protein level may have on the methionine requirement of broilers.