H. khandan Barani - Hamoun International Wetland Research Institute, University of Zabol, Zabol, Iran
H. Dahmardeh - Department of Fisheries, faculty of Natural Resources, University of Zabol, Zabol, Iran
M. Miri - Hamoun International Wetland Research Institute, University of Zabol, Zabol, Iran
M. Rigi - Hamoun International Wetland Research Institute, University of Zabol, Zabol, Iran

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 ۲.۱۷±۰.۱ g were fed a commercial diet (۴۰% protein, ۳.۸ Kcal g-۱ diet) at five ration sizes of ۲%, ۴%, ۶%, ۸% and ۱۰% of their body weight per day, for ۶۰ days. The 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 ۴–۶% body weight. Second-degree polynomial regression analysis for PER, FCR and ERE indicated the break-points occurred at ۴.۹, ۵.۱ and ۵.۲% BW day−۱, respectively. Maximum body protein content was obtained for ۴% and ۶% rations. Body moisture, fat and ash content remained unchanged. Based on the above results, it may be concluded that the ۴.۹-۵.۲% 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.

Growth, Body composition, Ration, Schizothorax zarudnyi