Effect of Processing Methods and Amino Acid Supplementation on Dietary Utilization of Feather Meal Protein by Chicks

Abstract

THE keratin proteins have generally been considered to be of little nutritive value because of their chemical structure which makes them insoluble and poorly digestible. Early attempts to use powdered sources of keratin as dietary protein were only slightly successful even when amino acid supplements were provided to offset the deficiencies of these proteins. Routh (1942) reported that powdered chicken feathers, as the sole source of protein for rats, were capable of supporting a moderate growth rate only when supplemented by tryptophan, methionine, histidine and lysine. Balance experiments conducted by Mangold and Dubski (1930) failed to show any digestion of white goose feathers by cats and owls. Thus it appeared that native feather keratin was not only seriously deficient in certain amino acids but was also poorly digestible. The development by Binkley and Vasak (1950) of a method for processing feathers into a friable, high density meal stimulated new…