Effects of body composition of gilts before first farrowing on their longevity

Body condition (body weight, backfat depth) was recorded on 829 gilts from 15 French herds when entering the herd (110 kg body weight), after quarantine phase and during first lactation. Sows performances and longevity were analysed using data from national record system (GTTT). Backfat depth at 110 kg had limited effects on lifespan. Average parity at culling (4.9) was similar to average French pig farms (5.1). Mortality rate was similar to value reported in literature (6.4 %). Nearly 65 % of sows culled during first parity got less than 13 mm backfat depth at weaning. For those culled after parity one, at least 50 % got more. Body weight and backfat losses at first weaning were lower in thinner and lighter sows at farrowing. This result tended to confirm the hypothesis that feed intake during lactation depends on body reserves at farrowing. As body reserves increased at weaning, lifespan and number of piglets produced per sow increased. Backfat depth after first lactation was not a good predictor of sows lifespan. However, it is a helpful criteria to adapt feeding level and optimise sows performances.