Nowland, T. L., van Wettere, W. H. E. J., Plush, K. J. Allowing sows to farrow unconfined has positive implications for sow and piglet welfare. Applied Animal Behaviour Science 221, 104872.

To reduce piglet mortality from overlay, farrowing crates confine the sow, restricting nest building activities. The aim of this study was to investigate the impact of confinement in the lead up to and during parturition on sow and litter characteristics. Sows (parity 1.6 ± 0.1) were housed in pens the size of a traditional crate with bars that allowed for temporary confinement. Two treatments were applied; OPEN (n = 36): pen was open until the sow stood following parturition, at which point they were closed, and CLOSED (n = 34): pen was closed through parturition. At d 10 of lactation the pens were opened for both treatments. A subset of sows (n = 12 CLOSED, n = 14 OPEN) were observed remotely during parturition and 18 h after parturition for behavioural analyses. Blood samples were collected hourly from −24 h until farrowing completion, and again at 24 h post farrowing. Piglet weights were collected at birth, 24 h and at weaning. OPEN sows displayed a reduced incidence of pain-related behaviours including tail flicks (8.4 ± 0.7 vs 27.6 ± 1.5; P < 0.001), movement of back leg forward (122.0 ± 3.0 vs 163.4 ± 3.7; P < 0.001) and strains (146.1 ± 3.2 vs 182.9 ± 3.9; P < 0.001) during farrowing. OPEN sows also nosed crate fixtures less frequently (4.1 ± 0.4 vs CLOSED 7.3 ± 0.8; P < 0.001) and performed more posture changes (23.2 ± 1.3 vs CLOSED 14.3 ± 1.1; P < 0.001) during farrowing. Confinement of sows did not impact plasma cortisol concentration at any point (P > 0.05). Sows from OPEN pens gave birth to fewer stillborn piglets than CLOSED (0.2 ± 0.1 vs 0.4 ± 0.1 piglets/litter respectively; P < 0.05). Colostrum ingestion was higher in piglets from OPEN sows (332.8 ± 7.8 g) than CLOSED (310.8 ± 7.0 g; P < 0.01). Individual weight at weaning was increased in piglets from OPEN sows (5.9 ± 0.2 kg) when compared with CLOSED (5.7 ± 0.2 kg; P < 0.01). Postnatal mortality did not differ between treatments (P < 0.05). Allowing the sow a greater freedom of movement exclusively in the lead up to and during parturition changes sow behaviour during this time and improves piglet growth whilst maintaining survival rates.