The pre-slaughter period including crowding, transfer, and fasting represents a critical welfare window for farmed salmon that determines the final hours of an animal's life.
The pre-slaughter period for farmed salmon has received increasing attention as the welfare costs of conventional harvesting methods have become apparent. Crowding fish to high densities for harvest causes acute stress, physical injury from crowding and collision, and physiological changes that persist through to slaughter. Fasting, while necessary for product quality, causes hunger stress and behavioural changes. Live hauling in air causes rapid hypoxia. Pre-slaughter in-water electrical stunning, where used, eliminates consciousness before the fish experiences the most stressful elements of the harvest process. The alignment between welfare improvement and product quality in pre-slaughter handling has driven commercial adoption of better methods in premium markets.