Rainbow trout aquaculture is the dominant salmonid farming system globally. Welfare challenges including disease, overcrowding, and transport require evidence-based management.
Farmed trout welfare reflects both the general challenges of intensive aquaculture and the specific vulnerabilities of salmonid species to disease and handling stress. Vaccination programs that dramatically reduce disease incidence represent a powerful welfare intervention that has been successfully implemented in leading trout-farming countries. The shift away from prophylactic antibiotic use through vaccination not only reduces environmental AMR risks but also prevents the welfare burden of disease outbreaks. Pre-slaughter welfare in trout requires effective electrical stunning that is systematically monitored for efficacy rather than assumed to work at all scales and fish sizes.