title: A n-3 PUFA depletion applied to rainbow trout fry (Oncorhynchus mykiss) does not modulate its subsequent lipid bioconversion capacity.
abstract: Nutritional strategies are currently developed to produce farmed fish rich in n-3 long-chain PUFA (LC-PUFA) whilst replacing fish oil by plant-derived oils in aquafeeds. The optimisation of such strategies requires a thorough understanding of fish lipid metabolism and its nutritional modulation. The present study evaluated the fatty acid bioconversion capacity of rainbow trout (Oncorhynchus mykiss) fry previously depleted in n-3 PUFA through a 60-d pre-experimental feeding period with a sunflower oil-based diet (SO) followed by a 36-d experimental period during which fish were fed either a linseed oil-based diet (LO) (this treatment being called SO/LO) or a fish oil-based diet (FO) (this treatment being called SO/FO). These treatments were compared with fish continuously fed on SO, LO or FO for 96 d. At the end of the 36-d experimental period, SO/LO and SO/FO fish recovered >80 % of the n-3 LC-PUFA reported for LO and FO fish, respectively. Fish fed on LO showed high apparent in vivo elongation and desaturation activities along the n-3 biosynthesis pathway. However, at the end of the experimental period, no impact of the fish n-3 PUFA depletion was observed on apparent in vivo elongation and desaturation activities of SO/LO fish as compared with LO fish. In contrast, the fish n-3 PUFA depletion negatively modulated the n-6 PUFA bioconversion capacity of fish in terms of reduced apparent in vivo elongation and desaturation activities. The effects were similar after 10 or 36 d of the experimental period, indicating the absence of short-term effects.
authors.affiliation: 1Institut des Sciences de la Vie,Université catholique de Louvain,Croix du Sud,2/L7.05.08,1348 Louvain-la-Neuve,Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: Mellery
authors.affiliation: 1Institut des Sciences de la Vie,Université catholique de Louvain,Croix du Sud,2/L7.05.08,1348 Louvain-la-Neuve,Belgium.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Brel
authors.affiliation: 1Institut des Sciences de la Vie,Université catholique de Louvain,Croix du Sud,2/L7.05.08,1348 Louvain-la-Neuve,Belgium.
authors.forename: Junio
authors.initials: J
authors.lastname: Dort
authors.affiliation: 2Unité de Recherche en Biologie Environnementale et Evolutive,Université de Namur,Rue de Bruxelles,61,5000 Namur,Belgium.
authors.forename: Florian
authors.initials: F
authors.lastname: Geay
authors.affiliation: 2Unité de Recherche en Biologie Environnementale et Evolutive,Université de Namur,Rue de Bruxelles,61,5000 Namur,Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kestemont
authors.affiliation: 3School of Life and Environmental Sciences,Deakin University,PO Box 423,Warrnambool,VIC 3280,Australia.
authors.forename: David S
authors.initials: DS
authors.lastname: Francis
authors.affiliation: 1Institut des Sciences de la Vie,Université catholique de Louvain,Croix du Sud,2/L7.05.08,1348 Louvain-la-Neuve,Belgium.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Larondelle
authors.affiliation: 1Institut des Sciences de la Vie,Université catholique de Louvain,Croix du Sud,2/L7.05.08,1348 Louvain-la-Neuve,Belgium.
authors.forename: Xavier
authors.initials: X
authors.lastname: Rollin
mesh_terms: D000821:Animal Feed; D000818:Animals; D017756:Aquaculture; D004032:Diet; D044943:Fatty Acid Desaturases / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D005395:Fish Oils / Q000378:metabolism / Q000494:pharmacology; D008043:Linseed Oil / Q000378:metabolism* / Q000494:pharmacology; D050356:Lipid Metabolism; D044342:Malnutrition / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000254:growth & development / Q000378:metabolism*; D010938:Plant Oils / Q000378:metabolism* / Q000494:pharmacology; D000074242:Sunflower Oil
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005395:Fish Oils; D010938:Plant Oils; D000074242:Sunflower Oil; D008043:Linseed Oil; D044943:Fatty Acid Desaturases
keywords:  ALA 
                    α-linolenic acid;  CD coefficient of distance;  DGC daily growth coefficient;  FE feed efficiency;  FO fish oil-based diet;  LA linoleic acid;  LC-PUFA long-chain PUFA;  LO linseed oil-based diet;  SO sunflower oil-based diet;  SO/FO SO until day 60 and then FO from days 61–96;  SO/LO SO until day 60 and then LO from days 61–96; Fatty acid metabolism; Lipid bioconversion capacity; Plant-derived oils; Rainbow trout; Whole body fatty acid balance method