Plasma concentrations and dietary requirements of leucine, isoleucine and valine: Studies with the young chick

Abstract The minimal requirements of the chick for leucine, isoleucine and valine have been assessed using diets based on wheat, groundnut meal and crystalline amino acids. The results of these studies clearly indicate that a relatively low isoleucine concentration of 0.52% allows satisfactory growth rate and efficiency of food conversion with the dietary levels of leucine and valine maintained at 0.98 and 0.63%, respectively. No beneficial response occurs to further supplementation with isoleucine. However, a higher isoleucine level (0.76 %) augments the requirements of leucine and valine to 1.10 and 0.75%, respectively, as judged by growth and efficiency of food conversion responses. These patterns of interactions are reflected in the plasma concentrations of leucine, isoleucine and valine.