Evaluating Cottonseed Meal Protein for Chick Growth by Enzymatic Release of Amino Acids

IN A previous study by Ingram, Riesen, Cravens and Elvehjem (1949) it was found that a good measure of the biological value of the protein of soybean oil meal for chick growth could be obtained by subjecting the meal to enzymatic hydrolysis and then measuring the amounts of certain amino acids that were liberated in a given period of time. The soybean oil meal samples were first subjected to acid hydrolysis and the amino acid content determined microbiologically. After enzymatic hydrolysis similar determinations were carried out and the percentage of the amino acids liberated by the enzymes calculated. Good correlation was found between these values and the growth supported by the same soybean meal samples in chicks. The studies reported here were undertaken to determine if this in vitro technique would also accurately measure the relative biological value of different cottonseed meal samples. Since the work of Olcott and Fontaine . . .