Influence of different levels of dietary choline on growth rate, body composition, Hematological indices and liver lipid of juvenile Siberian sturgeon Acipenser baerii Brandt, 1869

A 12-week feeding trial was carried out to evaluate the effects of different levels of dietary choline on growth rate, body composition and total liver lipid of juvenile Siberian sturgeon, Acipenser baerii. A semi-purified basal diet was formulated using vitamin-free casein and wheat gluten as a protein source, a mixture of animal and plant oils as a lipid source, and dextrin as a carbohydrate source. Graded levels of choline chloride were used at 0, 2000, 4000, and 8000mgkg(-1) diet (actual choline concentrations: 0, 1500, 3500 and 7500mgkg(-1) diet) were added to the basal diet. Juvenile Acipenser baerii with initial mean weights of 37.67 +/- 2.92g were held in fiberglass tanks (500l) and fed to apparent satiation three times per day. Weight gain, feed conversion ratio (FCR), specific growth rate (SGR) and protein efficiency ratio (PER) were significantly affected by dietary choline concentrations (P<0.05). The best growth performance was observed in fish fed diets containing 1500 and 7500mgkg(-1) choline chloride (P<0.05). Fish fed with diets containing 1500 and 3500mgkg(-1) choline chloride showed the highest lipid content in carcasses, but there were no significant differences (P>0.05) in protein and ash contents. Total lipid of liver and plasma, plasma cholesterol, triglyceride and phospholipids levels showed an increasing trend with increasing levels of dietary choline, but such an increase was not significant (P>0.05). The results of this study revealed that the optimum dietary choline chloride level for normal growth performance of juvenile Acipenser baerii appears to be 1500mgkg(-1).