Methods for stress assessment and management in farmed salmonids : sanitary, zootechnical and environmental implications

• Main Author: Delfosse, Cyril
• Other Authors: Département Sciences Agronomiques et Agroalimentaires - EI Purpan, Ecole d'Ingénieurs de Purpan (INP - PURPAN), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Institut National Polytechnique de Toulouse - INPT, Patrick Pageat, Cécile Bienboire-Frosini
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2017
• Subjects: Salmonids; Stress; Farming; Welfare; Parasitism; Semiochemistry; Salmonidés; Elevage; Bien-être; Parasitisme; Sémiochimie; [SDV.SA]Life Sciences [q-bio]/Agricultural sciences; Atlantic salmon
• Online Access: https://theses.hal.science/tel-04214983; https://theses.hal.science/tel-04214983/document; https://theses.hal.science/tel-04214983/file/DELFOSSE_Cyril.pdf

From hatching to slaughter, Atlantic salmon and Rainbow trout are subjected to several stressful events. Stress impairs physiological, behavioral and zootechnical performances of animals. The public interest in animal welfare brings us to study the assessment and control methods of stress in farmed salmonids. To do that, we studied the consequences of two different stressful events and proposed a method for assessing welfare of freshwater Rainbow trout. We also studied the interaction between stress and pathology with the salmon louse Lepeophtheirus salmonis. After developing an attractiveness test of salmon for the parasite, we investigated the influence of shortand long-term stress on salmon attractiveness for the parasite. Handling stress increased attractiveness of salmon for the parasite, while there was no difference between chronically stressed and control salmon. We proposed then a method to control this parasite by isolating a semiochemical which inhibit the hooking behavior of the parasite on the host. These results open interesting prospects for improving the assessment and control methods of stress in farmed salmonids. The investigation of stress consequences on animal welfare and on production performances is crucial. The semiochemical inhibiting the hooking behavior of the parasite on the salmon needs more studies to identify its mechanisms of action for use in farms. De l’éclosion à l’abattage, le saumon Atlantique et la truite arc-en-ciel d’élevage sont soumis à divers événements inducteurs de stress. Le stress influe directement sur la physiologie, le comportement et les performances zootechniques des animaux. Ainsi, l’intérêt grandissant du public pour le bien-être des animaux nous a amené à améliorer les connaissances sur le stress des salmonidés d’élevage pour en proposer des méthodes d’évaluation et de contrôle. Partant de ce constat, nous avons étudié les conséquences de deux situations inductrices de stress et proposé une méthode d’évaluation du bien-être de la truite arc-en-ciel d’eau ...