Replacement of fish meal with corn gluten meal in feeds for Asian sea bass (Lates calcarifer)

Abstract

A 45-day feeding trial was conducted to study the effect of replacing dietary fish meal (FM) with corn gluten meal (CGM) on diet digestibility and growth and proximate body composition of Asian seabass (Lates calcarifer) fingerlings (21.1 ± 0.95 g). Five isonitrogenous and isocaloric diets, formulated to contain 40% protein and 10% lipid, were prepared with fish meal replacement at 0 (control), 5, 10, 15, and 20% (w/w basis) using CGM. The trial was carried out in 1000-L fiber-reinforced polymer (FRP) tanks with three replicates (each containing 20 fish) for each treatment, and fish were hand fed in excess twice daily at 10.00 and 16.00 h. There was no significant difference in final body weight, average daily gain, and survival for fish fed the CGM0, CGM5, and CGM10 diets, with fish in these treatments performing better than the others. Feed conversion ratios for fish fed CGM0 (1.73 ± 0.05 g feed /g gain), CGM5 (1.65 ± 0.06 g feed g−1 gain), and CGM10 (1.84 ± 0.07 g feed g−1 gain) were better than for the other treatments. Protein retention (28.85 ± 0.65%) and energy retention (20.60 ± 0.39%) were better in the group fed with CGM5 than the other treatments. Apparent digestibility coefficients of dry matter (65.1 ± 0.3, 64.7 ± 0.2%), protein (91.6 ± 0.5, 91.7 ± 0.3%), and energy (79.0 ± 0.27, 8.4 ± 0.1%) were highest for the CGM5 and CGM10 diets. Highest crude lipid (7.29 ± 0.09%) and gross energy (7.19 ± 0.05 kJ g−1) were observed in fish fed the CGM 20 diet. The results indicate that CGM is a potential feed ingredient for seabass and can be included at 10% of the diet without compromising digestibility and growth.