Reducing sow confinement during farrowing and in early lactation increases piglet mortality

The aim of this study was to investigate the effect of sow confinement and nonconfinement during parturition and early lactation on the performance of sows and piglets prior to weaning. Sows and their litters were housed in either a conventional farrowing crate (control; 1.7 x 2.4 m) or a swing-sided pen (2.8 x 2.15 m). Sows housed in the swing-sided pen had the crate open (open) or closed (closed) during farrowing and opened on d 3 (LAC3) or 7 (LAC7) of lactation. Data are means +/- SEM. The numbers of total and live-born piglets were not different between treatments and averaged 13.1 +/- 0.4 and 12.3 +/- 0.2 piglets/litter, respectively. Sows housed in a farrowing crate had a greater (P = 0.03) number of stillborn piglets compared with open sows from pens (1.1 +/- 0.2 vs. 0.6 +/- 0.1 piglets/litter, respectively). Live-born piglet mortality before litter equalization on d 1 was greater (P < 0.01) for open sows compared with closed and control sows (1.6 +/- 0.2 vs. 0.9 +/- 0.2 vs. 1.1 +/- 0.1 piglets/litter, respectively) and was largely explained by an increase in the incidence of piglets overlain (P < 0.01) in the open compared to closed and control sows (1.3 +/- 0.1 vs. 0.5 +/- 0.1 vs. 0.8 +/- 0.1 piglets/litter, respectively). Overlay mortality between d 3 and 7 of lactation was greater (P = 0.03) in LAC3 sows compared to LAC7 and control sows (0.4 +/- 0.1 vs. 0.2 +/- 0.1 vs. 0.2 +/- 0.1 piglets/litter, respectively). Treatment did not affect either the incidence or cause of piglet mortality after d 7 of lactation (P > 0.05). Total live-born piglet mortality from birth until weaning for the control, closedLAC7, closedLAC3, openLAC7, and openLAC3 was 1.86 +/- 0.19, 1.95 +/- 0.23, 2.10 +/- 0.39, 2.45 +/- 0.27, and 3.74 +/- 0.48, piglets/litter, respectively. Total live-born piglet mortality from birth until weaning was greater in the openLAC3 and openLAC7 treatments compared to control (P < 0.01), and openLAC3 was also greater than openLAC7, closedLAC3, and closedLAC7 (P < 0.01). The current data indicated that reducing sow confinement during parturition decreased stillborn number but increased live-born piglet mortality compared to a farrowing crate, and removing confinement on d 3 of lactation further increased total piglet mortality compared to removing sow confinement on d 7 of lactation in sows that farrowed open. Sows that were confined during farrowing and until d 3 or 7 of lactation in a swing-sided pen had a similar piglet mortality compared to those in a farrowing crate.