Sow longevity is both a productivity and welfare indicator, with long-lived sows showing better adaptation and fewer welfare problems than frequently replaced young sows.
High sow culling rates indicate that welfare problems accumulate faster than sows can be maintained productively. A pig system where 40-50% of animals are culled annually due to health and structural problems has endemic welfare failures. Supporting longer sow lifetimes through genetics, housing, and management represents both a welfare and sustainability improvement. Lifetime welfare is better served by systems that allow sows to reach later parities in good health.