title: Fatty acid metabolism in European sea bass (Dicentrarchus labrax): effects of n-6 PUFA and MUFA in fish oil replaced diets.
abstract: Monounsaturated fatty acids (MUFA)-rich and n-6 polyunsaturated fatty acid (n-6 PUFA)-rich vegetable oils are increasingly used as fish oil replacers for aquafeed formulation. The present study investigated the fatty acid metabolism in juvenile European sea bass (Dicentrarchus labrax, 38.4 g) fed diets containing fish oil (FO, as the control treatment) or two different vegetable oils (the MUFA-rich canola/rapeseed oil, CO; and the n-6 PUFA-rich cottonseed oil, CSO) tested individually or as a 50/50 blend (CO/CSO). The whole-body fatty acid balance method was used to deduce the apparent in vivo fatty acid metabolism. No effect on growth performance and feed utilization was recorded. However, it should be noted that the fish meal content of the experimental diets was relatively high, and thus the requirement for n-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) may have likely been fulfilled even if dietary fish oil was fully replaced by vegetable oils. Overall, relatively little apparent in vivo fatty acid bioconversion was recorded, whilst the apparent in vivo β-oxidation of dietary fatty acid was largely affected by the dietary lipid source, with higher rate of β-oxidation for those fatty acids which were provided in dietary surplus. The deposition of 20:5n-3 and 22:6n-3, as % of the dietary intake, was greatest for the fish fed on the CSO diet. It has been shown that European sea bass seems to be able to efficiently use n-6 PUFA for energy substrate, and this may help in minimizing the β-oxidation of the health benefiting n-3 LC-PUFA and thus increase their deposition into fish tissues.
authors.affiliation: Department of Aquaculture, Faculty of Fisheries, Çukurova University, 01330 Adana, Turkey. mtufan@cu.edu.tr
authors.forename: Tufan O
authors.initials: TO
authors.lastname: Eroldoğan
authors.forename: Asuman H
authors.initials: AH
authors.lastname: Yılmaz
authors.forename: Giovanni M
authors.initials: GM
authors.lastname: Turchini
authors.forename: Murat
authors.initials: M
authors.lastname: Arslan
authors.forename: Necdet A
authors.initials: NA
authors.lastname: Sirkecioğlu
authors.forename: Kenan
authors.initials: K
authors.lastname: Engin
authors.forename: Ilgin
authors.initials: I
authors.lastname: Özşahinoğlu
authors.forename: Pınar
authors.initials: P
authors.lastname: Mumoğullarında
mesh_terms: D000818:Animals; D001492:Bass / Q000378:metabolism*; D003369:Cottonseed Oil / Q000008:administration & dosage*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage / Q000378:metabolism*; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000378:metabolism*; D011897:Random Allocation; D000074262:Rapeseed Oil
chemical_list: D003369:Cottonseed Oil; D005229:Fatty Acids, Monounsaturated; D043371:Fatty Acids, Omega-6; D000074262:Rapeseed Oil