The 'n-3 LC-PUFA sparing effect' of modified dietary n-3 LC-PUFA content and DHA to EPA ratio in Atlantic salmon smolt

• Published in: Aquaculture
• Main Authors: Codabaccus, MB, Carter, CG, Bridle, AR, Nichols, PD
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Science Bv 2012
• Subjects: Agricultural and Veterinary Sciences; Fisheries Sciences; Aquaculture; Atlantic salmon
• Online Access: https://doi.org/10.1016/j.aquaculture.2012.05.024; http://ecite.utas.edu.au/81131

n−3 Long-chain (≥C 20 ) polyunsaturated fatty acids (LC-PUFA) are used extensively by fish via β-oxidationwhen in dietary surplus. Therefore it is of interest to optimize n−3 LC-PUFA deposition in fish via a reductionin β-oxidation which may be induced by manipulation of dietary fatty acids. This study tested whether Atlanticsalmon smolt fed a dietwith a higher docosahexaenoic acid (DHA):eicosapentaenoic acid (EPA) ratio and a lowercontent of n−3 LC-PUFA to that of fish oil (FO) based diets would enhance deposition of n−3 LC-PUFA in fishtissues. Comparisons were made between fish fed: a FO diet, a blend of 50% rapeseed and 50% tuna oil diet(model oil, MO 1), a blend of 50% rapeseed, 25% tuna and 25% FO diet (MO 2), and a blend of 50% FO and 50%chicken fat diet (FO/CF). The dietary DHA:EPA ratio was in the order MO 1>MO 2>FO/CF~FO. Dietary n−3LC-PUFA content was approximately 2-fold lower in fish fed the MO 1, MO 2 and FO/CF diets compared to theFO diet. There were comparable amounts of n−3 LC-PUFA in the muscle of FO,MO1 and FO/CF fed fish. Our findingsindicate that the right balance in both absolute and relative amounts of EPA and DHA can promote n−3LC-PUFA retention.