Space allowance for dry, pregnant sows in pens: Body condition, skin lesions, and performance

Different floor space allowances for dry, pregnant sows in pens were evaluated to determine the impacts of space on sow performance, productivity, and body lesions during 2 consecutive farrowings. Treatment groups of 5 sows/pen were assigned to 1.4, 2.3, or 3.3 m ² of floor space/sow or of 5 sows in individual stalls (1.34 m ²). The experiment consisted of 6 replications (blocks 1 to 6), and within each block measurements were recorded for 2 consecutive pregnancies and farrowings. A total of 152 sows were measured at 1 farrowing, and 65 of those sows were measured at the successive farrowing (n = 217 records). Performance traits were BCS, BW, backfat (BF), days until rebred, and proportion culled. Litter traits were number of piglets born alive, male:female ratio, and proportions of stillborn, mummified, or dead piglets after birth. Litter performance measures were mean piglet BW and gain and litter BW. Lesion scores were assessed for several body regions. There were treatment and parity effects and interactions for several traits. An interaction of space treatment and parity occurred for sow mean BW, d-110 BW, BF, litter size, and litter and piglet BW and gain, with most effects in parity 2, 3, and 4 sows. Space affected sow mean (P < 0.001) and d-110 BW (P < 0.05) and mean BF and adjusted BF (P < 0.001); sows in pens at ≤2.3 m ² of space had greater (P < 0.05) BW and BF depth, and primiparous sows had less (P < 0.05) BW than greater parity sows. Few differences were found for litter traits, except for litter size, litter weaning BW, and pig B W gain. Sows in pens at 3.3 m2 had the largest (P < 0.05) litters. Weaning BW was greater (P < 0.05) for litters born to sows that gestated in stalls. Sow BCS and lesion score were affected by floor space (P < 0.001) and parity (P < 0.01); BCS was reduced in sows in pens at 1.4 m ², and their lesion score was consistently greater (P < 0.05) than that of other space allowances. Primiparous sows often had the least (P < 0.05) lesion scores. For sows in pens, linear and quadratic responses were detected for many of the traits assessed. As floor space increased, BW and BF increased (P < 0.01), but as space decreased, lesion scores increased. Although the effects of gestation system were found and lesion scores often were greater as space decreased, differences in productivity traits were unremarkable with respect to sow welfare or performance compared with industry norms.