Purified diets containing six levels of leucine were fed to growing rats to evaluate the leucine
requirement for maintenance and for growth. A model was employed to separate the leucine
requirement for maintenance from its requirement for growth. Based on weight gain
response, the leucine need for growth was 13.24 mg/g live weight gain and the maintenance
requirement was 0.40 mg per unit of metabolic body size (W g· 75). The plateau of blood
plasma leucine concentration was reached at 99 mg leucine intake/day. Previous leucine …