Rainbow trout are one of the most farmed fish globally, yet welfare at slaughter varies enormously depending on stunning method and implementation quality.
Trout have well-developed nociceptive systems and show clear behavioural and physiological responses to noxious stimuli. CO2 immersion as a pre-slaughter method causes observable avoidance behaviour and stress before fish lose consciousness. Electrical stunning and effective percussive stunning can render fish unconscious rapidly and humanely. Ensuring slaughter personnel are trained and equipment is maintained in good working order is essential for welfare-consistent slaughter.