Growth performance, fatty acid profile, antioxidant capacity, liver and gut histopathology in Asian seabass (Lates calcarifer) fed various levels of oxidized fish oil and vitamin E

چکیده مقاله

A 60-day research was carried out to investigate interactive effects of dietary oxidized fish oil (OXFO) and
vitamin E (Vit E) interaction effects on the growth, body composition and health indices in Asian seabass juveniles (Lates calcarifer, 21.9 ± 0.1 g). Fresh fish oil (FFO) and two levels of OXFO (50 and 100 % dietary inclusion level) along with three levels of Vit E (125, 250 and 500 mg) were used to design a 3 × 3 factorial
research trial. Accordingly, nine experimental diets were formulated, including FFO+125 (FFO + 125 mg Vit E),
FFO+250 (FFO + 250 mg Vit E), FFO+500 (FFO + 500 mg Vit E), 50 %OXFO+125 (blends (1:1) of FFO + OXFO
+125 mg Vit E), 50 %OXFO+250 (blends (1:1) of FFO + OXFO +250 mg Vit E), 50 %OXFO+500 (blends (1:1) of
FFO + OXFO +500 mg Vit E), 100 %OXFO+125 (OXFO +125 mg Vit E), 100 %OXFO+250 (OXFO +250 mg Vit E)
and 100 %OXFO+500 (OXFO +500 mg Vit E). Four hundred five L. calcarifer juveniles were stocked into twentyseven 300-L circular tanks (15 fish/tank), in a flow through system. The greatest and least final weights were
recorded in fish fed 50 %OXFO+250 and 100 %OXFO+125 diets (129.4 vs. 114.8 g final weight) diets, respectively.
Whole body lipid content in fish fed FFO+125 increased compared to the other treatments. Fish oil oxidation
significantly reduced Vit E concentration in the liver, meanwhile supplementing diet with 500 mg Vit E enhanced
Vit E contents of the liver and muscle (P < 0.05). Eicosapentaenoic acid and long chain polyunsaturated fatty
acids (LC-PUFA) contents of fillet increased with increasing dietary OXFO content to 50 %, and supplementing
diet with 250 mg Vit E enhanced LC-PUFA content of fillet. Hepatic catalase, superoxide dismutase and glutathione peroxidase activities reduced by supplementing diets with Vit E. Sever pathological alterations occurred in
liver and gut of L. calcarifer by dietary inclusion of OXFO or high Vit E concentration (500 mg). In summary,
supplementing OXFO containing diets with moderate levels of Vit E (250 mg) could improve growth performance
and feed utilization by ameliorating oxidative stress indices, improving antioxidant capacity, and increasing
body LC-PUFA content in L. calcarifer