What is the impact of sow longevity on technical and economic performance in pig farms?

The aim of this study is to describe the variability of sow longevity in French pig farms and to investigate its possible impact on technical and economic outcomes. The analysis is performed using data from the French National Pig Management database (GTTT‐GTE) and includes 1033 production herds with both reproduction results and technico‐economic performances recorded in 2009. Average number of litters at culling in 2009is used as a synthetic criterion to measure sow longevity at herd level. The effect of low (≤ 4.5 litters, 18% herds), medium (]4.5‐6] litters, 59% herds) or high longevity (> 6 litters, 23% herds) are tested in interaction with herd size(≤ 125, 125‐200, >200 sows), region, age at weaning (3 vs 4 weeks), batch management (4‐5‐10, 7 or 20-21 batches) and replacement strategy (purchase vs self‐production). Size, age at weaning or batch management do not differ according to herd longevity profiles. Herds with high sow longevity are more frequently located in the north‐west, and have less frequent self‐production of gilts. They have significantly lower replacement and culling rates with fewer culls for reproduction or locomotor reasons. High longevity is associated with high productivity and better ability to maintain litter size for parities >6.Relation between economic results and longevity is poor, because it depends on herd demography (% of gilts vs parities>6) and on the ability to maintain high level of performance in older sows.