Temporary confinement of sows for four days after farrowing has little influence on postural changes

Confinement of loose-housed sows for a few days after farrowing where piglets are at greatest risk of dying can potentially reduce piglet mortality. Moreover, sow behaviour in early lactation is characterised by prolonged lateral lying (Baxter et al. 2011), indicating that the physical restriction imposed by confinement might not be as detrimental for sow welfare in this period of time compared to other, more active periods. This study aimed at investigating if confinement for 4 days after farrowing influenced sow behaviour, with the hypothesis examined that loose-housed sows had more postural changes than loose-housed sows.

The study was conducted in a Danish piggery with SWAP (Sow Welfare And Piglet protection) farrowing pens. Sows were randomly allocated to one of three treatments: loose-loose (LL: loose from placement in the farrowing unit to weaning; n = 20); loose-confined (LC: loose from entry to end of farrowing and confined to d 4 after farrowing; n = 19); and confined-confined (CC: confined from d 114 of gestation to d 4 after farrowing; n = 19). All sows were loose housed from d 4 of lactation to weaning, after 4 weeks. Behavioural observations of sow postures (standing, sitting, lying sternally and lying laterally) were obtained from video recordings on days 1, 2 and 3 after farrowing in the time intervals 0400–0600 h, 1000–1200 h, 1600–1800 h, and 2200–2400 h. Data were statistically analysed by use of linear models (SAS^®; USA) (PROC MIXED).

Regardless of treatment, sow behaviour was characterised by a low frequency of postural changes (<12 postural changes in 2-h bouts) and a large proportion of time spent in lateral recumbency (80–120 min of 2-h bouts), especially on d 1 and 2 after farrowing. Postural changes increased during the day in all treatments but more so in LL than LC and CC (P = 0.02) (Fig. 1a). Similarly, the frequency of rolling (changes between lateral and sternal postures) increased from d 1 to d 3 after farrowing in all treatments, but LL had a greater increase than LC and CC (P < 0.001). Time spent lying laterally was similar across treatments (P = 0.66) (Fig. 1b). Sows generally spent more time standing during daytime intervals than night-time intervals, but the diurnal pattern was dissimilar in the three treatments (P < 0.01) and differed in the three days (P < 0.01).

Fig. 1.  Postural changes (a) and time spent lying laterally (b) in 2-h observation bouts at d 1 to 3 after farrowing for loose-housed sows (LL –), sows that were confined from the end of farrowing to day 4 after farrowing (LC –), and sows that were confined from gestation d 114 to d 4 after farrowing (CC - -).

Loose-housed sows displayed a different behavioural pattern than sows that were confined to d 4 after farrowing (treatment LC and CC). Differences however were mainly seen on d 3, indicating that sow behaviour was only marginally affected by confinement in the first days of lactation. In conclusion, the results suggested that confinement for 4 days after farrowing had little influence on sow behaviour.