Feeding predictability as a cognitive enrichment protects brain function and physiological status in rainbow trout: a multidisciplinary approach to assess fish welfare - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement
Journal Articles Animal Year : 2024

Feeding predictability as a cognitive enrichment protects brain function and physiological status in rainbow trout: a multidisciplinary approach to assess fish welfare

Jérôme Roy
Élodie Baranek
  • Function : Author
  • PersonId : 1403812
  • IdRef : 275780260
Vanessa Guesdon
  • Function : Author
  • PersonId : 1406004

Abstract

Cognitive enrichment is a promising but understudied type of environmental enrichment that aims to stimulate the cognitive abilities of animals by providing them with more opportunities to interact with (namely, to predict events than can occur) and to control their environment. In a previous study, we highlighted that farmed rainbow trout can predict daily feedings after two weeks of conditioning, the highest conditioned response being elicited by the combination of both temporal and signalled predictability. In the present study, we tested the feeding predictability that elicited the highest conditioned response in rainbow trout (both temporal and signalled by bubbles, BUBBLE+TIME treatment) as a cognitive enrichment strategy to improve their welfare. We thus analysed long-term effects of this feeding predictability condition as compared with an unpredictable feeding condition (RANDOM treatment) on the welfare of rainbow trout, including the markers in the modulation of brain function, through a multidisciplinary approach. To reveal the brain regulatory pathways and networks involved in the long-term effects of feeding predictability, we measured genes markers of cerebral activity and plasticity, neurotransmitters pathways and physiological status of fish (oxidative stress, inflammatory status, cell type and stress status). After almost three months under these predictability conditions of feeding, we found clear evidence of improved welfare in fish from BUBBLE+TIME treatment. Feeding predictability allowed for a food anticipatory activity and resulted in fewer aggressive behaviours, burst of accelerations, and jumps before mealtime. BUBBLE+TIME fish were also less active between meals, which is in line with the observed decreased expression of transcripts related to the dopaminergic system. BUBBLE+TIME fish tented to present fewer eroded dorsal fin and infections to the pathogen Flavobacterium psychrophilum. Decreased expression of most of the studied mRNA involved in oxidative stress and immune responses confirm these tendencies else suggesting a strong role of feeding predictability on fish health status and that RANDOM fish may have undergone chronic stress. Fish emotional reactivity while isolated in a novel-tank as measured by fear behaviour and plasma cortisol levels were similar between the two treatments, as well as fish weight and size. To conclude, signalled combined with temporal predictability of feeding appears to be a promising approach of cognitive enrichment to protect brain function via physiological status of farmed rainbow trout in the long term.
Fichier principal
Vignette du fichier
Calvez24Animal.pdf (1.27 Mo) Télécharger le fichier
Origin Publisher files allowed on an open archive
Licence

Dates and versions

hal-04426412 , version 1 (21-03-2024)

Licence

Identifiers

Cite

Aude Kleiber, Jérôme Roy, Valentin Brunet, Élodie Baranek, Jean-Michel Le Calvez, et al.. Feeding predictability as a cognitive enrichment protects brain function and physiological status in rainbow trout: a multidisciplinary approach to assess fish welfare. Animal, 2024, 18 (3), pp.101081. ⟨10.1016/j.animal.2024.101081⟩. ⟨hal-04426412⟩
131 View
33 Download

Altmetric

Share

More