title: Preliminary Validation of a High Docosahexaenoic Acid (DHA) and α-Linolenic Acid (ALA) Dietary Oil Blend: Tissue Fatty Acid Composition and Liver Proteome Response in Atlantic Salmon (Salmo salar) Smolts.
abstract: Marine oils are important to human nutrition as the major source of docosahexaenoic acid (DHA), a key omega-3 long-chain (≥C20) polyunsaturated fatty acid (n-3 LC-PUFA) that is low or lacking in terrestrial plant or animal oils. The inclusion of fish oil as main source of n-3 LC-PUFA in aquafeeds is mostly limited by the increasing price and decreasing availability. Fish oil replacement with cheaper terrestrial plant and animal oils has considerably reduced the content of n-3 LC-PUFA in flesh of farmed Atlantic salmon. Novel DHA-enriched oils with high alpha-linolenic acid (ALA) content will be available from transgenic oilseeds plants in the near future as an alternative for dietary fish oil replacement in aquafeeds. As a preliminary validation, we formulated an oil blend (TOFX) with high DHA and ALA content using tuna oil (TO) high in DHA and the flaxseed oil (FX) high in ALA, and assessed its ability to achieve fish oil-like n-3 LC-PUFA tissue composition in Atlantic salmon smolts. We applied proteomics as an exploratory approach to understand the effects of nutritional changes on the fish liver. Comparisons were made between fish fed a fish oil-based diet (FO) and a commercial-like oil blend diet (fish oil + poultry oil, FOPO) over 89 days. Growth and feed efficiency ratio were lower on the TOFX diet. Fish muscle concentration of n-3 LC-PUFA was significantly higher for TOFX than for FOPO fish, but not higher than for FO fish, while retention efficiency of n-3 LC-PUFA was promoted by TOFX relative to FO. Proteomics analysis revealed an oxidative stress response indicative of the main adaptive physiological mechanism in TOFX fish. While specific dietary fatty acid concentrations and balances and antioxidant supplementation may need further attention, the use of an oil with a high content of DHA and ALA can enhance tissue deposition of n-3 LC-PUFA in relation to a commercially used oil blend.
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia.|CSIRO Food Nutrition and Bio-based Products, Oceans & Atmosphere, GPO Box 1538, Hobart, TAS 7001, Australia.
authors.forename: Waldo G
authors.initials: WG
authors.lastname: Nuez-Ortín
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia.
authors.forename: Chris G
authors.initials: CG
authors.lastname: Carter
authors.affiliation: Central Science Laboratory, University of Tasmania, Bag 74, Hobart, TAS 7001, Australia.
authors.forename: Richard
authors.initials: R
authors.lastname: Wilson
authors.affiliation: Department of Molecular and Cell Biology, James Cook University, Townsville, QLD 4811, Australia.
authors.forename: Ira
authors.initials: I
authors.lastname: Cooke
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia.|CSIRO Food Nutrition and Bio-based Products, Oceans & Atmosphere, GPO Box 1538, Hobart, TAS 7001, Australia.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Nichols
mesh_terms: D000821:Animal Feed; D000818:Animals; D001699:Biometry; D002853:Chromatography, Liquid; D004281:Docosahexaenoic Acids / Q000737:chemistry* / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D005395:Fish Oils / Q000737:chemistry*; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D020543:Proteome; D040901:Proteomics / Q000379:methods; D020317:Salmo salar / Q000254:growth & development / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D017962:alpha-Linolenic Acid / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D005395:Fish Oils; D020543:Proteome; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids