title: Long-term feeding a plant-based diet devoid of marine ingredients strongly affects certain key metabolic enzymes in the rainbow trout liver.
abstract: Incorporation of a plant blend in the diet can affect growth parameters and metabolism in carnivorous fish. We studied for the first time the long-term (1 year) metabolic response of rainbow trout fed from first feeding with a plant-based diet totally devoid of marine ingredients. Hepatic enzymes were analyzed at enzymatic and molecular levels, at 3, 8 and 24 h after the last meal to study both the short-term effects of the last meal and long-term effects of the diet. The results were compared with those of fish fed a control diet of fish meal and fish oil. Growth, feed intake, feed efficiency and protein retention were lower in the group fed the plant-based diet. Glucokinase and pyruvate kinase activity were lower in the livers of trout fed the plant-based diet which the proportion of starch was lower than in the control diet. Glutamate dehydrogenase was induced by the plant-based diet, suggesting an imbalance of amino acids and a possible link with the lower protein retention observed. Gene expression of delta 6 desaturase was higher in fish fed the plant-based diet, probably linked to a high dietary level of linolenic acid and the absence of long-chain polyunsaturated fatty acids in vegetable oils. Hydroxymethylglutaryl-CoA synthase expression was also induced by plant-based diet because of the low rate of cholesterol in the diet. Changes in regulation mechanisms already identified through short-term nutritional experiments (<12 weeks) suggest that metabolic responses are implemented at short term and remain in the long term.
authors.affiliation: INRA UR 1067 NuMeA (Nutrition Metabolism Aquaculture), Aquapôle, 64310, Saint Pée Sur Nivelle, France. viveron@st-pee.inra.fr.
authors.forename: Vincent
authors.initials: V
authors.lastname: Véron
authors.affiliation: INRA UR 1067 NuMeA (Nutrition Metabolism Aquaculture), Aquapôle, 64310, Saint Pée Sur Nivelle, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Panserat
authors.affiliation: INRA, UMR1313 GABI (Génétique animale et biologie intégrative), Jouy-En-Josas, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Le Boucher
authors.affiliation: INRA, UE 0937 PEIMA (Pisciculture Expérimentale INRA des Monts d'Arrée), Sizun, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Labbé
authors.affiliation: INRA, UMR1313 GABI (Génétique animale et biologie intégrative), Jouy-En-Josas, France.
authors.forename: Edwige
authors.initials: E
authors.lastname: Quillet
authors.affiliation: INRA, UMR1313 GABI (Génétique animale et biologie intégrative), Jouy-En-Josas, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Dupont-Nivet
authors.affiliation: INRA UR 1067 NuMeA (Nutrition Metabolism Aquaculture), Aquapôle, 64310, Saint Pée Sur Nivelle, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Médale
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D017756:Aquaculture / Q000379:methods*; D004032:Diet / Q000379:methods*; D005227:Fatty Acids; D005941:Glucokinase; D017686:Oncorhynchus mykiss / Q000502:physiology*; D010938:Plant Oils
chemical_list: D005227:Fatty Acids; D010938:Plant Oils; D005941:Glucokinase
keywords: Activity; Dietary adaptation; Expression; Fish; Nutrition