The effects of partial weaning, movement and boar contact on the subsequent reproductive performance of lactating sows

Abstract

ABSTRACTForty multiparous Large White × Landrace sows were randomly allocated to five treatment groups: (1) control (C) — no partial weaning, movement or boar contact, (2) partial weaning (PW) only — sow and litter separated for 12 h/day, (3) PW + boar contact (B) in the sow's pen (1 h/day), (4) PW + sow moved (M) to empty pen (1 h/day), (5) PW + sow moved to occupied boar pen (1 h/day). Treatments were imposed from day 10 post partum until weaning at day 35 (s.e. 1). All sows were generously fed throughout lactation (7 kg/day) and in the post-weaning period (3 kg/day). One sow (treatment 5) exhibited lactational oestrus and was mated on day 33 of lactation, while the remaining sows on treatments 2 to 5 had significantly reduced (P < 0·05) weaning to remating intervals relative to control sows (4·84 v. 6·63 days, respectively). Litter creep food intakes tended to be higher in PW litters than controls (512 v. 376 g/day; P > 0·05), whereas sow live-weight gains during lactation were significantly increased when PW was employed (+0·43 kg/day v. −0·13 kg/day for control sows; P < 0·001). Partial weaning significantly (P < 0·001) reduced litter weaning weights (74·8 v. 87·0 kg for controls). However, there were no significant treatment effects on individual piglet weaning weights, subsequent growth performance of the weaned litters, or the size of litter subsequently produced by the sows.