Stimulating prepartum nest-building behaviour through alternative nesting materials has impacts on farrowing kinetics and maternal characteristics in crated sows

The process of nest-building plays a crucial role in parturition, as it has the potential to impact fetal expulsion and reproductive performance of sows. This study aimed to investigate the effect of providing alternative nesting materials (sling belt and rag) on prepartum nest-building behaviour, farrowing process, and postpartum maternal behaviour of sows housed in crates. Thirty-two (21 Landrace and 11 Yorkshire) purebred sows (average parity, 2.66 +/- 0.277; range, 1-6) were randomly divided into three groups and housed in farrowing crates with no nesting material (control, n = 9), or with sling belt (SB, n = 9), or with sling belt and rag (SBR, n = 11). The sows' behaviours were assessed by analyzing top-view video recordings. The nest-building behaviours of the sows were observed during the 24-h period before parturition. Three days after parturition, nursing behaviour was assessed and carefulness toward the piglets was scored after observing for 24 h. The duration and frequency of nest-building behaviour in the SB group was higher than those of that in the control group but lower than those of that in the SBR group (P < 0.05 for both). The duration of sternal lying in sows in the SB group was significantly higher than that of those in the control and SBR groups during parturition (P < 0.001). The control group exhibited higher frequency of bar-biting than did the other two groups, as observed 24 h before parturition (P < 0.001). Multiple comparisons showed that the SBR group had the shortest farrowing duration, followed by the SB and control groups (P < 0.001). Furthermore, the SBR group exhibited shorter birth interval than did the control or SB group (P < 0.01). Total and successful nursing durations in the control group were longer than those in the other groups (P < 0.001), whereas the SBR group showed shorter duration of unsuccessful nursing than did the other two groups (P < 0.01). In conclusion, the provision of a sling belt and rag could facilitate nest-building behaviour, resulting in an enhancement of farrowing process and nursing performance of sows confined in farrowing crates. Collectively, we confirmed the availability of using sling belt and rag as alternative nesting materials for peripartum sows housed in farrowing crate with slatted flooring.