Enrichment with Lucerne Hay Improves Sow Maternal Behaviour and Improves Piglet Survival

SIMPLE SUMMARY: This study investigated how access to a high-value enrichment item (lucerne hay) impacted the welfare of sows in farrowing crates during nesting, farrowing and lactation. Compared to the control group (no nest building material), in which sows in farrowing crates were given 1 kg of lucerne hay daily, they performed more nest-building and less stereotypical behaviour in the 18 h prior to farrowing and gave birth to fewer stillborn piglets. Shortly after farrowing, the control sows performed less interactions with their piglets during early lactation than they did during late lactation, suggesting a reduction in early maternal behaviour for this group. The lucerne sows continued to interact with the lucerne during the 17-day lactation period, indicating that they still found this enrichment rewarding even after the nest-building period had finished. Based on these results, lucerne enrichment was considered to improve sow welfare during farrowing and throughout lactation. These results support the provision of lucerne enrichments under confined farrowing conditions that continue through lactation to improve both sow welfare and piglet survival. ABSTRACT: This study investigated the effects of providing lucerne hay on the behaviour and the performance of sows housed in farrowing crates during farrowing and lactation. Seventy-two mixed parity sows received either 1 kg lucerne hay daily from entry into the farrowing crate (−2 d from expected farrowing date) until weaning at 17 d (lucerne group, n = 36), or received no additional enrichment (control group, n = 36). In the 18 h prior to farrowing, the sows in the lucerne treatment spent more time performing nest-building behaviour (14.8% lucerne vs 11.1% control, p = 0.0009) and less time sham-chewing (1.0% lucerne vs 1.9% control, p = 0.01) than control sows, and gave birth to fewer stillborn piglets/litter (0.1 lucerne vs 0.4 control, p = 0.027). After farrowing (Day 3), the control sows spent less time lying than the lucerne sows (26% control vs 43% lucerne, p < 0.05). The control sows also spent less time interacting with their piglets during early lactation compared to late lactation (25.5% Day 5 vs 47.3% Day 12, p < 0.05), suggesting reduced maternal behaviour in this group. The lucerne sows continued to interact with the lucerne throughout lactation, indicating that they still found the enrichment rewarding after the nesting period had ceased. Based on these results, lucerne enrichment was considered to improve sow welfare during farrowing and lactation and reduce the number of stillborn piglets.