title: The positive impact of the early-feeding of a plant-based diet on its future acceptance and utilisation in rainbow trout.
abstract: Sustainable aquaculture, which entails proportional replacement of fish-based feed sources by plant-based ingredients, is impeded by the poor growth response frequently seen in fish fed high levels of plant ingredients. This study explores the potential to improve, by means of early nutritional exposure, the growth of fish fed plant-based feed. Rainbow trout swim-up fry were fed for 3 weeks either a plant-based diet (diet V, V-fish) or a diet containing fishmeal and fish oil as protein and fat source (diet M, M-fish). After this 3-wk nutritional history period, all V- or M-fish received diet M for a 7-month intermediate growth phase. Both groups were then challenged by feeding diet V for 25 days during which voluntary feed intake, growth, and nutrient utilisation were monitored (V-challenge). Three isogenic rainbow trout lines were used for evaluating possible family effects. The results of the V-challenge showed a 42% higher growth rate (P = 0.002) and 30% higher feed intake (P = 0.005) in fish of nutritional history V compared to M (averaged over the three families). Besides the effects on feed intake, V-fish utilized diet V more efficiently than M-fish, as reflected by the on average 18% higher feed efficiency (P = 0.003). We noted a significant family effect for the above parameters (P<0.001), but the nutritional history effect was consistent for all three families (no interaction effect, P>0.05). In summary, our study shows that an early short-term exposure of rainbow trout fry to a plant-based diet improves acceptance and utilization of the same diet when given at later life stages. This positive response is encouraging as a potential strategy to improve the use of plant-based feed in fish, of interest in the field of fish farming and animal nutrition in general. Future work needs to determine the persistency of this positive early feeding effect and the underlying mechanisms.
authors.affiliation: INRA, UR1067 NUMEA Nutrition, Métabolisme et Aquaculture, Aquapôle INRA, Saint Pée-sur-Nivelle, France.
authors.forename: Inge
authors.initials: I
authors.lastname: Geurden
authors.affiliation: INRA, UR1067 NUMEA Nutrition, Métabolisme et Aquaculture, Aquapôle INRA, Saint Pée-sur-Nivelle, France ; Aquaculture and Fisheries Group, Wageningen Institute of Animal Sciences (WIAS), Wageningen University, Wageningen, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Borchert
authors.affiliation: INRA, UR1067 NUMEA Nutrition, Métabolisme et Aquaculture, Aquapôle INRA, Saint Pée-sur-Nivelle, France.
authors.forename: Mukundh N
authors.initials: MN
authors.lastname: Balasubramanian
authors.affiliation: INRA, UR1067 NUMEA Nutrition, Métabolisme et Aquaculture, Aquapôle INRA, Saint Pée-sur-Nivelle, France.
authors.forename: Johan W
authors.initials: JW
authors.lastname: Schrama
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, UMR1313 GABI Génétique Animale et Biologie Intégrative, Jouy-en-Josas, France.
authors.forename: Edwige
authors.initials: E
authors.lastname: Quillet
authors.affiliation: INRA, UR1067 NUMEA Nutrition, Métabolisme et Aquaculture, Aquapôle INRA, Saint Pée-sur-Nivelle, France.
authors.forename: Sadasivam J
authors.initials: SJ
authors.lastname: Kaushik
authors.affiliation: INRA, UR1067 NUMEA Nutrition, Métabolisme et Aquaculture, Aquapôle INRA, Saint Pée-sur-Nivelle, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Panserat
authors.affiliation: INRA, UR1067 NUMEA Nutrition, Métabolisme et Aquaculture, Aquapôle INRA, Saint Pée-sur-Nivelle, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Médale
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D017756:Aquaculture / Q000379:methods*; D004032:Diet; D017686:Oncorhynchus mykiss / Q000254:growth & development / Q000502:physiology*; D013997:Time Factors