Sow Longevity and Welfare in Pig Production

Sow Longevity and Welfare

Sow longevity — the productive lifespan of breeding females — is both a welfare and an economic measure of pig production efficiency. High culling rates in commercial herds reflect poor sow welfare outcomes and signal underlying management or genetic problems that should be addressed.

Current Industry Context

Average sow longevity in many commercial systems is only 2-3 parities (litters) before culling, far below the 5-7 parity potential of well-managed sows. High turnover requires greater replacement rates, increasing the welfare burden across the population.

Main Causes of Early Culling

Lameness: Musculoskeletal problems are the leading cause of sow culling — 30-35% of involuntary culls in many herds.
Reproductive failure: Anoestrus, repeat breeding, and low litter size drive economic culling.
Prolapse: Uterine or rectal prolapse — often related to constipation, farrowing management, and body condition.
Body condition deterioration: Sows that become excessively thin through repeated lactations ('parity-2 syndrome') cannot sustain production.
Injury: Fighting injuries, bite wounds, and trauma from housing or handling.

Welfare Dimensions of Longevity

Short sow longevity is not just an economic indicator — it reflects chronic welfare problems. Lame sows experience ongoing pain. Prolapse is a painful emergency. Thin sows suffer from inadequate nutrition relative to metabolic demands. Improving longevity inherently improves welfare across the sow's lifetime.

Management for Improved Longevity

Gilt selection and development: Selecting for leg soundness and managing gilt growth rate to avoid osteochondrosis.
Nutrition management: Ensuring adequate nutrient intake during lactation to prevent excessive body condition loss.
Body condition monitoring: Regular BCS assessment and intervention to maintain BCS 3.0-3.5 throughout the reproductive cycle.
Flooring: Non-slip, comfortable flooring reduces the risk of leg injuries and lameness.
Housing design: Adequate space in group housing to reduce aggression and competition.
Lameness management: Early identification and treatment of lame sows; foot bathing and chiropody as preventive measures.
Genetics: Selecting sire lines for maternal traits including leg soundness and longevity.

Key Takeaways

Improving sow longevity is simultaneously a welfare and business improvement. Addressing the root causes of early culling — particularly lameness, reproductive failure, and body condition management — creates a more sustainable and welfare-positive production system.