Dietary Protein and Lipid Requirements for Juvenile Largemouth Bass, Micropterus salmoides

A feeding trial was conducted to evaluate dietary protein and lipid requirements for juvenile largemouth bass, Micropterus salmoides. A 4x2-factorial layout included four protein (420, 450, 480, and 510 g/kg) and two lipid (80 and 120 g/kg) levels. Fish (initial weight 8.7 g) were fed the test diets for 8 wk. Weight gain, feed intake, feed conversion ratio, hepatosomatic index, and body composition were dependent on dietary protein level. Nitrogen retention efficiency was independent of dietary protein level, lipid level, and their interaction. Weight gain was higher in fish fed the diet containing 480-510 g/kg crude protein than in fish fed the diet containing 420-450 g/kg crude protein at two dietary lipid levels. The feed intake and weight gain were higher in fish fed the diet containing 484 g/kg crude protein and 115 g/kg crude lipid than in fish fed the diet containing 478 g/kg crude protein and 77 g/kg crude lipid. This study indicated that the suitable dietary protein and lipid levels for largemouth bass are 480-510 g/kg and 120 g/kg, respectively.