The Effects of Various Processing Methods on the Value of Cottonseed Meal as an Amino Acid Source for Chickens

FOR simple-stomached animals, the nutritional value of cottonseed meal is determined primarily by its protein value; however, this protein evaluation is complicated by the fact that the cottonseed contains gossypol, a yellow pigment that is harmless to ruminants, but toxic to poultry, swine, and rats (Hale and Lyman, 1948). If cottonseeds are subjected to heat, moisture, pressure, and shearing action during oil removal, most of the gossypol becomes bound into an unavailable form. The processing techniques that are most effective in reducing the available gossypol are, unfortunately, also most harmful to protein quality (Altschul, 1954). In the present work, the protein quality of a number of meal samples was determined by a chick assay procedure in which all the amino acids of the diet came from the sample under study. No whole grains were used since these contribute significant amounts of amino acids that may affect the evaluation of the …