Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/28176
Appears in Collections:Aquaculture Journal Articles
Peer Review Status: Refereed
Title: Performance, feed utilization, and hepatic metabolic response of weaned juvenile Atlantic bluefin tuna (Thunnus thynnus L.): effects of dietary lipid level and source
Author(s): Betancor, Monica B
Ortega, Aurelio
de la Gandara, Fernando
Tocher, Douglas R
Mourente, Gabriel
Keywords: Atlantic bluefin tuna
dietary lipid content
dietary lipid source
production 43 performance
hepatic lipid metabolism
gene expression
Issue Date: Apr-2019
Citation: Betancor MB, Ortega A, de la Gandara F, Tocher DR & Mourente G (2019) Performance, feed utilization, and hepatic metabolic response of weaned juvenile Atlantic bluefin tuna (Thunnus thynnus L.): effects of dietary lipid level and source. Fish Physiology and Biochemistry, 45 (2), pp. 697-718. https://doi.org/10.1007/s10695-018-0587-9
Abstract: Two trials were performed using extruded diets as on-growing feeds for weaned Atlantic bluefin tuna (Thunnus thynnus; ABT) to establish adequate dietary levels of both lipid and omega-3 long-chain polyunsaturated fatty acids (LC-PUFA), and impacts on lipid metabolism via liver gene expression. In Trial A, ABT were fed with either a commercial feed (Magokoro®, MGK) as a reference diet, or two experimental feeds differing in lipid levels (15 or 20 %) using krill oil (KO) as the single lipid source in order to estimate suitable lipid content. Fish fed MGK displayed the highest growth, followed by 15KO, and therefore a dietary lipid content of 15 % was considered preferable to 20 % at this stage. In Trial B, fish were fed MGK, 15KO or a feed containing 15 % lipid with a blend of KO and rapeseed oil (RO) (1:1, v/v; 15KORO). Fish fed 15KO and 15KORO showed no difference in weight gain, specific growth rate and fork length. Increasing dietary lipid level or including vegetable oil, RO, in the feeds did not increase liver lipid content. Liver fatty acid compositions largely reflected dietary profiles confirming very limited endogenous LC-PUFA biosynthesis. Liver of ABT fed 15KO and 20KO displayed the highest contents of docosahexaenoic acid (DHA). The hepatic expression of genes encoding enzymes and transcription factors involved in lipid and fatty acid metabolism, as well as genes encoding antioxidant enzymes, showed that many of these genes were regulated by dietary lipid and LC-PUFA content. Results suggested that ABT juveniles can be on-grown on inert dry feeds that support good fish growth and the accumulation of DHA.
DOI Link: 10.1007/s10695-018-0587-9
Rights: © The Author(s) 2018 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

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