Carefulness and flexibility of lying down behaviour in sows during 24h post-partum in relation to piglet position

This study focused on sow lying down behaviour and on the flexibility of her pre-lying behaviour, both of which are supposed to be crucially linked to piglet crushing. First, during 24h after the birth of the first piglet (BFP) changes in the frequency of standing-to-lying events were investigated in 18 sows housed in farrowing crates. The 24h were split into four time periods for use in the statistical analyses (0-2h, 2.01-6.00h, 6.01-16.00h, 16.01-24.00h). A carefulness score which includes sniffing, rooting, pawing, lying down vertically and “no piglets in danger zone” was calculated for each standing-to-lying event. We also determined whether a pre-lying behaviour index (consisting of the incidence of sniffing, rooting and pawing) and its duration were influenced by piglet location (sow area vs. creep area) and piglet clustering. Every crushing event was noted. The carefulness score was lower 6h after BFP then increased and remained stable until the end of the 24h. Sows changed their pre-lying behaviour independently from the time period but not from piglet position as sows showed more and longer pre-lying behaviours when piglets were in the sow area and/or when piglets were already clustered at the start of the pre-lying behaviour, independent of where they clustered. Although the pre-lying behaviour increased the probability of clustering, it did not affect the probability that piglets moved from the sow to the creep area immediately before lying down. A higher carefulness score as well as “no piglets in the danger zone” were associated with a lower probability of crushing, whereas the pre-lying behaviour had no influence. The results emphasize that sows are flexible in the pre-lying behaviour during this early piglet age. Further research should focus on factors which decrease the probability that piglets are present in the danger zone and specifically on sow and piglets communication during pre-lying behaviour.