title: Nutritional Evaluation of an EPA-DHA Oil from Transgenic Camelina sativa in Feeds for Post-Smolt Atlantic Salmon (Salmo salar L.).
abstract: Vegetable oils (VO) are possible substitutes for fish oil in aquafeeds but their use is limited by their lack of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA). However, oilseed crops can be modified to produce n-3 LC-PUFA such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, representing a potential option to fill the gap between supply and demand of these important nutrients. Camelina sativa was metabolically engineered to produce a seed oil with around 15% total n-3 LC-PUFA to potentially substitute for fish oil in salmon feeds. Post-smolt Atlantic salmon (Salmo salar) were fed for 11-weeks with one of three experimental diets containing either fish oil (FO), wild-type Camelina oil (WCO) or transgenic Camelina oil (DCO) as added lipid source to evaluate fish performance, nutrient digestibility, tissue n-3 LC-PUFA, and metabolic impact determined by liver transcriptome analysis. The DCO diet did not affect any of the performance or health parameters studied and enhanced apparent digestibility of EPA and DHA compared to the WCO diet. The level of total n-3 LC-PUFA was higher in all the tissues of DCO-fed fish than in WCO-fed fish with levels in liver similar to those in fish fed FO. Endogenous LC-PUFA biosynthetic activity was observed in fish fed both the Camelina oil diets as indicated by the liver transcriptome and levels of intermediate metabolites such as docosapentaenoic acid, with data suggesting that the dietary combination of EPA and DHA inhibited desaturation and elongation activities. Expression of genes involved in phospholipid and triacylglycerol metabolism followed a similar pattern in fish fed DCO and WCO despite the difference in n-3 LC-PUFA contents.
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
authors.forename: Mónica B
authors.initials: MB
authors.lastname: Betancor
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Sprague
authors.affiliation: Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom.
authors.forename: Olga
authors.initials: O
authors.lastname: Sayanova
authors.affiliation: Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: Usher
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
authors.forename: Christoforos
authors.initials: C
authors.lastname: Metochis
authors.affiliation: Biomar Ltd., North Shore Road, Grangemouth FK3 8UL, United Kingdom.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Campbell
authors.affiliation: Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom.
authors.forename: Johnathan A
authors.initials: JA
authors.lastname: Napier
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Tocher
mesh_terms: D000821:Animal Feed; D000818:Animals; D019607:Brassicaceae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004281:Docosahexaenoic Acids / Q000737:chemistry; D015118:Eicosapentaenoic Acid / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D015525:Fatty Acids, Omega-3 / Q000737:chemistry; D020869:Gene Expression Profiling; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008099:Liver / Q000378:metabolism; D008247:Lysosomes; D060847:Metabolic Engineering; D015596:Nutrition Assessment; D009928:Organ Specificity; D009195:Peroxidase; D010936:Plant Extracts / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D030821:Plants, Genetically Modified; D020317:Salmo salar / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry; D059467:Transcriptome
chemical_list: D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D008055:Lipids; D010936:Plant Extracts; D010938:Plant Oils; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D009195:Peroxidase