Fish oil partial replacement by vegetable oils in diets for european seabass (Dicentrarchus labrax); effects on growth performance and fatty acids profile

This study was conducted in Çukurova University, Faculty of Fisheries, Yumurtalık Marine Station. Triplicate groups of 20 European sea bass (45.15 ? 0,15 g) were fed four cold press-pelleted diets in which the added lipid was 100% fish oil (FO), 50% FO+50% sesame (FO/SO), 50% FO+50% canola oil (FO/CO) and %50 FO+50% soybean oil (FO/SBO) for a period of 90 days. There were no effects of diet on specific growth rate, feed conversion and protein utilization. However, the final body weight of fish fed on FO and FO/SO was significantly higher than the fish fed on FO/CO and FO/SBO (p?0.05). Also, no significant difference was found on lipid, dry matter and ash content of whole fish (p>0.05) whereas highest protein content was in fish fed FO and FO/SBO diets (p<0.05). As expected, whole body fatty acid composition mirrored those of dietary treatments. There were no effects of diet on saturated fatty acids and high unsaturated fatty acids (p>0,05) whilst the mono unsaturated fatty acids (primarily 16:1n-7 and 18:1n-9) content of fish fed FO/SO and FO/CO diets (p<0.05). While linolenic was highly deposited in whole body of fish fed FO/SO there were no significant difference was observed in the other dietary treatments (FO, FO/CO and FO/SBO) concerning this fatty acid. Finally, a blend of SO might be used as a substitute for fish oil in the culture of European sea bass.Key Words: European Sea Bass, Alternative Oil Source, Soybean Oil, Sesame Oil, Canola Oil