Effect of Varying Protein and Lipid Levels on the Growth of Rohu, Labeo rohita

Rohu (Labeo rohita, Cyprinidae) fingerlings (7.5 g) were fed six experimental diets containing two protein levels (25 and 30%) and three lipid levels (4, 6 and 9%) for 98 d. The best growth was obtained with the diet containing 30% protein and 6% lipid. At a given protein/fat level, increase in fat/protein resulted in better weight gain, except in the diet having 30% protein and 9% lipid. Protein efficiency ratio and net protein retention decreased with increase in dietary protein. Muscle RNA/DNA reflected the growth trend. Gut protease and lipase activity had a direct relationship with dietary protein. Dietary fat influenced carcass fat content, but dietary protein had no effect on carcass protein.