Turkish Journal of Fisheries and Aquatic Sciences
2015, Vol 15, Num, 1 (Pages: 1-12)
Effects of Fish Oil Substitution with Two Different Vegetable Oil Classes on Fatty Acid Digestibility in Juvenile European Sea Bass, Dicentrarchus labrax
Hatice Asuman Yılmaz 1 ,Orhan Tufan Eroldoğan 1
1 Çukurova University, Faculty of Fisheries, Department of Aquaculture, Adana, Turkey
DOI :
10.4194/1303-2712-v15_1_01
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This study evaluated dietary polyunsaturated fatty acid (PUFA)/highly unsaturated fatty acid (HUFA) ratios in European
sea bass subjected to feeds containing fish oil (FO) or two different vegetable oils (the monounsaturated fatty acid: MUFArich
rapeseed oil, RO; and the n-6 PUFA-rich cottonseed oil, CSO). Triplicate groups of twenty fish (35-g ± 0.2) were fed
three fish-based diets in which the added lipid was 100% fish oil (FO), 100% refined low-erucic-acid-rapeseed oil (RO),
100% cottonseed oil (CSO) for a period of 130 days. As a result of this study, final weight, weight gain and specific growth
rate were significantly higher in fish fed FO and RO diet compared to fish fed CSO. Final weight in fish fed the RO diet were
significantly higher (87.3 ± 3.1 g) in comparison to fish fed the FO (84.3 ± 1.2 g) and CSO diets (80.4±2.3, p<0.05). The
concentration of eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) in flesh was significantly reduced with
increasing levels of MUFA and n-6 PUFA in the diet. Accordingly, DHA value in fish fed the CSO diet was 9.41% whereas
fish fed the RO diet had lower (7.93%) DHA content in the flesh. As expected, the absorption of individual dietary fatty acids
decreased with chain length and increased with the degree of unsaturation. The apparent total lipid digestibility decreased with
increasing the PUFA/HUFA ratio in the diet.
Keywords :
β-oxidation, chain length, degreee of unsaturation, digestibility