Effect of dietary betaine supplementation on growth indices, hematology and resistance of Schizothorax zarudnyi to salinity stress

The aim of this study was to investigate of betaine effect on growth performance, hematology and resistance of Schizothorax zarudnyi to salinity stress. For this purpose, 120 fish (6.58±0.29 g) were fed with levels of 0 (control), 0.5% (treatment 1), 1% (treatment 2) and 2% (treatment 3) 2 times per day for 8 weeks. At the end of the period, the fish were biometric and exposed to 20 g. L-1 salinity stress for two hours. Results of this study showed, significant difference in growth parameters (Mean of final weight and length, SGR,CF and FCR) between fish fed betaine supplementation diets and control group (p<0.05). In addition, the results of  blood factors indicated that betaine had no effect on hematocrit, hemoglobin, red and white blood cells count and no significant difference was observed between treatments and control(p>0.05). Resistant to salinity stress in Schizothorax zarudnyi were fed to betaine, was more than the control group. Based on the results of this study, it seems that betaine supplementation diets can increase the growth and resistance of Schizothorax zarudnyi.