Systems of expressing the protein values of the feed and methods of their estimation

Abstract

In chemical composition studies, proteins in the feeds are estimated by determining the nitrogen content and multiplying by a factor 6.25 and the resultant value is the crude protein. However, considerable variation in the efficiency of conversion of different dietary sources of proteins have been reported in the literature using isonitrogenous diets, and these variations have been attributed to the quality difference among proteins particularly in their amino acids profile. The following terms are widely used in the biological evaluation of proteins In fishes and crustaceans.