The Amino Acid Composition and the Nutritive Value of Proteins

Abstract
The minimum requirements for the essential amino acids by the weanling rat for maximum growth have been determined, using casein-amino acid diets at the 10% protein level. Growth tests were of 21 days' duration. The requirements for lysine, histidine, tryptophan, isoleucine, leucine, valine, threonine, methionine + cystine, and phenylalanine + tyrosine are: 0.9, 0.21, 0.11, 0.55, 0.69, 0.56, 0.51, 0.49 and 0.72% of the diet, respectively.