Short-term starvation at low temperature prior to harvest does not impact the health and acute stress response of adult Atlantic salmon

• Main Authors: Waagbø, Rune, Jørgensen, Sven Martin, Timmerhaus, Gerrit, Breck, Olav, Olsvik, Pål A
• Format: Other/Unknown Material
• Language: unknown
• Published: PeerJ 2017
• Subjects: Atlantic salmon
• Online Access: http://dx.doi.org/10.7287/peerj.preprints.2837; https://peerj.com/preprints/2837.pdf; https://peerj.com/preprints/2837.xml; https://peerj.com/preprints/2837.html

Period of starvation is regarded as a sound practice in aquaculture prior to handling, transportation and harvest, to minimise impacts on welfare and ensure proper hygiene after harvest. However, documentation of welfare issues such as stress following starvation and handling in adult Atlantic salmon are lacking. This study aimed to examine gut emptying and potential stress during a two weeks starvation period, and whether this starvation period changes the tolerance for physical stress. The study confirmed slower emptying of the gut segments at low temperature. Plasma and bile cortisol, and selected clinical analyses were used to characterize potential stress, as well as the response to acute physical crowding stress during the starvation period. Neither the general stress level nor the ability to cope with handling stress was affected by a 14 days starvation period. Down-regulation of selected nutritional related gene markers in liver indicated classical starvation responses, with reduced metabolism and oxidative pressure, and sparing of nutrients. The response to acute handling stress was not affected by two weeks of starvation. There were minor effects of starvation on stress and health markers, as evaluated by plasma lysozyme activity and gene expression of selected inflammation marker proteins in heart and skin tissues.