LAUSR

The aim of this study was to evaluate the dietary isoleucine requeriments for Nile tilapia juveniles based on growth performance, hematological and biochemical responses, and muscle growth. Three hundred Nile tilapia juveniles (18.09 ± 0.11 g) were distributed in 20 fiberglass tanks and fed with five extruded isoproteic (280 g.kg-1 of crude protein) and isoenergetic (3000 kcal.kg-1) formulated diets containing 7.00, 8.18, 9.35, 10.53, and 11.70 g.kg-1 of isoleucine. No differences were observed (P > 0.05) in productive performance, hematological and biochemical parameters, centesimal composition, amino acid body composition, and muscle growth. The isoleucine body retention reduced linearly with increased amounts of isoleucine in the diet. Because protein is the nutrient with the highest cost in fish diets, the results from this study contribute towards the formulation of efficient and cost effective diets for Nile tilapia juveniles.