“Dietary EPA and DHA boost viral disease resistance in Atlantic Salmon (Salmo salar) (7216)”

Dietary EPA and DHA boost viral disease resistance in Atlantic Salmon (Salmo salar)

Viral diseases represent a major health and economic challenge in global salmonid aquaculture. Diseases such as cardiomyopathy syndrome (CMS), heart and skeletal muscle inflammation (HSMI), jaundice syndrome, and pancreas disease (PD) have led to substantial losses and compromised fish welfare. Numerous studies have shown that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential for optimal salmonid growth and resilience to viral infections. This study aimed to determine whether higher dietary levels of EPA+DHA can enhance resistance to viral infections.

A 19-week feeding trial was conducted using a PD (salmonid alphavirus-3, SAV3) cohabitation challenge model at VESO Vikan, Norway. Atlantic salmon (initial weight ~25 g) were fed two isoproteic and isoenergetic diets containing two levels of EPA+DHA. After a 9-week pre-feeding (including smoltification), fish were exposed to SAV3 through cohabitation for 10 weeks in triplicate tanks. Fifteen fish per tank were biweekly sampled for post-challenge assessments of viral load in heart, plasma biomarkers including creatine kinase (CK) alanine transaminase (ALT) and aspartate transaminase (AST), and histopathological lesions in pancreas, heart, and skeletal muscle.

T-test and Mann-Whitney U analysis showed that fish fed higher levels of EPA+DHA had significantly lower SAV3 loads, reduced plasma CK, ALT, AST levels, and milder tissue lesions associated with PD. In conclusion, increasing dietary EPA+DHA enhances viral disease resistance. More details of the results will be presented and discussed at the conference.

1. GU, JINNI, BIOMAR AS, Presenter
2. SIGHOLT, TRYGVE, BIOMAR AS, Author
3. AASUM, ELISABETH, BIOMAR AS, Author