The Amino Acid Composition and Nutritive Value of Proteins

Abstract
To determine protein requirement using a “balanced” protein, male weanling rats were fed casein-amino acid diets ad libitum for three weeks; these diets provided all the essential amino acids at the minimum required levels. The total protein levels tested ranged from 7 to 15%. The minimum requirement of protein for maximum nitrogen retention was 10% of the diet, whereas for maximum growth it was only 8.8% of protein.