Effects of replacement of dietary fish oil by vegetable oils on growth parameters, chemical composition and fatty acids profile of cultured juvenile Beluga (Huso huso)
Subject Areas : New Technologies in Aquaculture Development
Keywords: Iran, fish oil, Huso huso, Vegetable oils, Keywords: Fatty acids,
Abstract :
Abstract[1] In this research, effects of replacement of different levels of vegetable oils instead of dietary fish oil on growth parameters, chemical composition and fatty acids profile of cultured Beluga juveniles (27.01±0.49 g) were studied for eight weeks. For this mean, three isonitrogenous and isolipidic diets were formulated, containing 10% of added oil. Diets were consisting of 100% kilka fish oil in the first treatment (control diet), 50% fish oil and 50% mixed vegetable oils (soybean and canola oils, 1:1) in the second treatment and 100% mixed vegetable oils (soybean, canola and sunflower oils, 1:1:1) in the third treatment. There were no significant differences in the growth performance parameters and food consumption consisting of WG%, K, GR, SGR, Feed intake, FCR, PER and also chemical composition of carcass, consisting of raw protein, raw fat, moisture and ash among different treatments. By the inclusion of dietary vegetable oils, n-6 polyunsaturated fatty acids (n-6 PUFA), particularly linoleic acid (18:2n-6) significantly increased in beluga carcass, but docosahexaenoic acid (DHA, 22:6n-3), n-3 polyunsaturated fatty acids (n-3 PUFA), n-3 highly unsaturated fatty acids (n-3 HUFA) and the ratio n-3/n-6 in beluga carcass were significantly reduced. Generally, the fatty acids composition of fish carcasses was highly reflective of the dietary lipid sources. With consideration to lack of significant difference, the fishes of second treatment obtained a better growth performance than other treatments and these results suggest that cultured Beluga require n-3, n-6 and n-9 fatty acids in diets. *Corresponding author; mnikzad1984@yahoo.com
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