The influence of different lipid sources and levels on growth, body composition and haematology of Huso huso

In order to improve feeding and growth of juvenile great sturgeon Huso huso, the effects of various lipid sources in feed were examined. Three hundred juveniles (initial body weight 215 ± 10 g) were distributed into 15 flow-through 1100 l tanks (20 fish per tank). Five experimental diets containing various lipid levels were formulated: diet C (control; without added oil), SO(L) and SO(H) diets containing soybean oil concentrations respectively, (53.5 vs. 174 g/kg), FO(L) and FO(H) diets containing fish oil with low and high concentrations respectively (53.5 vs. 174 g/kg). Fish were fed three times daily based on their appetite for a period of 6 weeks. At the termination of the experiment, growth rate was improved with increasing oil content in the diets. There were significant differences in final weights among fish fed the different experimental diets. Lipid content of muscle and liver significantly increased with increasing dietary lipid levels for both soybean and fish oil. The lowest cholesterol level and the highest haematocrit value were measured in fish fed the FO(H) diet. No significant difference was found among dietary treatments in terms of triacylglycerol concentration, number of red blood cell, mean corpuscular volume, mean corpuscular haemoglobin (MCH) and MCH concentration (MCHC). According to the most growth indices, results of this study suggest that the best results were observed in FO(H) which can be attributed to the greater palatability of diet containing high fish oil, supply of fatty acid requirement and enhanced physiological performance.