Effect of different ratio of dietary crude protein / energy on growth indices and body composition in Bester juveniles

The aim of this study was to investigate the effect of different dietary crude protein/energy ratios on growth indices and body composition of Bester juveniles. Triplicate groups (60 individuals per group) of fish (average weight ± SD, 358.4 ± 13.37g) were fed with three diet (D1, D2 and D3) including 31.67%, 35.54% and 40.86% of crude protein and 4377, 4800 and 5344 kcal of energy/kg, respectively, during eight weeks based on 1.5% of biomass per day. The result showed different significant of growth parameters (P<0.05). Body weight increase, condition factor, specific growth rate, average daily growth, protein productive value, and feed conversion ratio (FCR) improved in D2 and D3 treatment groups compared with D1. Comparison of the carcass composition of examined fish showed significant different between treatment groups (P<0.05). Therefore, the highest moisture, lipid and ash level of carcass gained in fish fed with diet D2 (P<0.05). Also highest carcass crude protein recorded in fish fed with diet D3 (P<0.05). These results suggested that the diet including 35.54% of crude protein and 4800 kcal of energy/kg is economic and suitable for culture of juvenile Bester.