Pre-harvest food withdrawal in farmed salmon causes hunger stress over 24-72 hours that serves production needs but represents a welfare harm requiring proportionate management.
Pre-harvest food withdrawal is a welfare harm with a production justification. Hungry fish experience increased aggression, elevated stress hormones, and behavioral indicators of feed-seeking motivation that reflects genuine hunger stress. The necessity of some food withdrawal for food safety does not eliminate the welfare obligation to minimize its duration and severity. Withdrawal periods longer than strictly necessary represent avoidable welfare harm. The welfare-conscious approach establishes the minimum food withdrawal time needed for food safety compliance and does not exceed it. Additionally, managing stocking density, water quality, and temperature during withdrawal reduces the severity of hunger-related stress during this unavoidable pre-slaughter period. Industry adoption of minimum necessary withdrawal periods as a welfare standard would benefit millions of fish annually.