THE EFFECTS OF PROVIDING SAWDUST TO PRE-PARTURIENT SOWS IN FARROWING CRATES ON SOW BEHAVIOR, THE DURATION OF PARTURITION AND THE OCCURRENCE OF INTRA-PARTUM STILLBORN PIGLETS

The behaviour of 174 sows (parities 1-10) in commercial farrowing crates was recorded at 10-min intervals around parturition. Approximately half of the sows received regular applications of sawdust on the floor of their crate during the pre-partum period (SD treatment). Control treatment (Con) sows did not receive sawdust. Younger sows (parities 1-3) in the SD treatment spent less (P < 0.01) time belly lying from 24 to 16 h pre-partum, were more (P < 0.05) active in the last 8 h pre-partum and less (P < 0.05) active during parturition than in the Con treatment. More root/nose/paw behaviour occurred during 24 to 16 h (P < 0.01 ) and the last 8 h (P < 0.005) pre-partum, and more (P < 0.03) feeder-directed behaviour occurred in the last 8 h pre-partum, in the SD than Con treatment. Sows in the SD treatment compared with sows in the Con treatment had a shorter (P < 0.05) mean duration of parturition (159 and 201 min per sow) and a lower (P < 0.01) incidence of piglets that were overlayed during parturition and the subsequent 6 h (2.4% and 21.1% of sows, respectively). While there were no differences in the proportion of litters of younger sows that contained stillborn piglets of the class intra-partum death (IPD: 26.1 and 31.6% of sows), there was a difference (P < 0.02) in the ratio of litters containing 0, 1 or multiple IPD per litter: (SD: 73%, 2 7% and 0% vs. Con: 68%, 16% and 16% of litters, respectively). As a consequence of the lower occurrence of IPD, litter size born alive was greater (P < 0.03) in the SD than Con treatment (10.5 and 10.0 piglets). Older sows (parities 4 and above) in the SD treatment spent less time sitting (P < 0.05) and more time side lying (P < 0.06), and performed less (P < 0.01) bar biting during the last 8 h pre-partum than older sows in the Con treatment. In conclusion, the application of sawdust during the pre-partum period appeared to stimulate prepartum activity in younger sows, including root/nose/paw behaviour, which may, in turn, positively affect the process of parturition and reduce overlaying of piglets, both of which are relevant to increasing piglet survival. The differing results for older sows suggest that experience with sawdust (for nesting material) is an important determinant of subsequent responses of farrowing sows to this material.