Feasibility study of the utilization of processed sheepskins as a protein supplement to the diet of chickens

Abstract

Dry woolled sheepskins were ground coarsely and treated with alkali or acid to render the protein digestible with proteases. A series of laboratory experiments showed that on autoclaving with 0 . 2 5M sulphuric acid or 0.10M caustic soda and subsequent neutralization the material was largely digestible with pepsin and a mixture of trypsin and chymotrypsin. The acid treatment caused little destruction of amino acids whereas the alkali treatment converted most of the cystine residues to products such as lanthionine. A bulk preparation obtained by boiling in 4M sulphuric acid for 1 hr, neutralizing with lime, filtering, and drying had a similar composition but most of the tryptophan was destroyed during preparation. In a feeding trial with chickens this material was shown to be a suitable substitute for meat and bone meal as a protein supplement.