اثرات منابع چربي جيره غذايي بر فاكتورهاي رشد، تغذيه و تركيب اسيدهاي چرب لاشه بچه فيل ماهيان پرورشي (huso huso)

Effects of dietary lipid sources on growth performance, nutrition and fatty acids composition in carcass of cultured Beluga (Huso huso) juveniles

In the present study, eight-week growth trials were carried out on 108 cultured beluga juveniles (mean weight 26.87±0.69 g) to study the effects of dietary lipid sources on growth performance and fatty acids profile in carcass. For this purpose, fish were fed three isonitrogenous and isolipidic diets formulated containing 10% of added oil. The first treatment with 100% Kilka fish oil (FO) was considered as the control diet, which was substituted by 50% of vegetable oils (VOs) consisting of sunflower (25%) and soybean oils (25%) in the second treatment, and sunflower (25%) and canola oils (25%) in the third treatment. FBW in the fishes of the first treatment was significantly lower than the other treatments (P<0.05), while no significantly difference was observed in the other parameters of growth performance consisting of WG%, K, SGR, FCR, PER among different treatments (P>0.05). Amount of the carcass ash in the third treatment fishes was significantly more than the other treatments (P<0.05). Other chemical compositions of carcass, consisting of crude protein, crude fat and moisture among different treatments were not significantly different (P>0.05). Linoleic acid (18:2n-6) and the ratio 18:ln-9/n-3 significantly increased in fish fed vegetable oil diets, but docosahexaenoic acid (DHA, 22:6n-3) and the ratio n-3/n-6 in beluga carcass were significantly reduced by the inclusion of dietary vegetable oils (P<0.05). Generally, fatty acid composition of fish carcasses reflected the dietary FA composition, a lot. Thus based on cost effectiveness, growth and fatty acid composition, experimental diet 2 (50% FO+25% sunflower oil+25% canola oil) was considered the best diet in this study.