The effects of feeding rates on growth performance, conversion efficiency and body composition of juvenile snow trout, Schizothorax zarudnyi

This study was performed to investigate the effects of feeding rates on growth performance, feed conversion and body composition of juvenile snow trout (Schizothorax zarudnyi). For this purpose, fish with an initial body weight of 2.17± 0.1 g were fed a commercial diet (40% protein, 3.8 Kcal/g diet) at five ration sizes 2%, 4%, 6%, 8% and 10% of their body weight per day, for 60 days. Feeding trial was conducted in triplicate. Maximum weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR %), highest energy retention (ERE %) and protein efficiency ratio (PER %) were evident for rations of 4–6% body weight. Second-degree polynomial regression analysis for PER, FCR and ERE indicated the break-points occurred at 4.9, 5.1 and 5.2% BW day−1, respectively. Maximum body protein content was obtained for 4% and 6% rations. Body moisture, fat and ash content remained unchanged. Based on the above results, it may be concluded that 4.9-5.2% body weight per day ration is optimal for the growth, conversion efficiencies and body composition of juvenile S. zarudnyi and it entails favorable economic benefits.