Rainbow trout is the most farmed salmonid globally, with a mature evidence base on welfare threats from crowding, disease, and handling that informs modern certification standards.
Rainbow trout welfare science is among the most developed in aquaculture, providing a strong evidence base for certification standards. Critical welfare points include stocking density management, disease prevention through vaccination and prophylactic screening, and stunning at slaughter. Handling events — grading, transport, treatment — are major acute welfare stressors requiring minimisation and monitoring. Evidence consistently shows that welfare-optimal conditions also optimise feed conversion and growth rate — the economic and welfare incentives align.