Slaughter welfare for pigs involves the entire sequence from lairage through stunning to killing, with controlled atmosphere stunning systems now considered the gold standard for minimizing suffering.
The welfare of pigs at slaughter depends critically on the effectiveness of the stunning method used and the conditions in which animals approach the kill point. CO2 stunning causes aversive gasping and squealing during induction that indicates distress, yet remains the most common commercial method. High concentration inert gas stunning using nitrogen produces unconsciousness more rapidly with less aversive experience. Improving global slaughter welfare standards to require more humane stunning methods would reduce the acute suffering of billions of pigs each year at the end of their lives.