Impact of Duration of Farrowing Crate Closure on Physical Indicators of Sow Welfare and Piglet Mortality

SIMPLE SUMMARY: Many sows when lactating are housed in farrowing crates. This is to protect their piglets from being crushed when the sow lies down and is particularly vital in the first few days of the piglet’s life. There are many ways that crates can be configured, one that allows flexibility in considering the sow’s mobility and the safety of piglets is the hinged farrowing crate. This type of crate opens to allow the sow room to move around but can also be closed like a conventional farrowing crate. For farmers to use this crate, however, they need to understand when is the optimal time to open the crate that protects the piglet while allowing sows improved freedom of movement. In this study, we examined three groups, including one where the crate was always closed, a group where the crate was opened at four days after birth, and a group where the crate was opened at seven days of age. Our results indicate that opening the crates decreases sow’s risk for teat lesions, and crates can be opened at 7 days of age without increasing piglet mortality. ABSTRACT: This study examines effects of opening hinged farrowing crates 4 or 7 days post-farrowing. Sows (n = 696) allocated to 3 treatments: PC—crate closed, T4—crate opened day 4, and T7—crate opened day 7 were assessed for body condition score (BCS), lameness, shoulder lesions and teat lesions. Piglet mortality was higher in T4 (27.8%) compared to T7 (23.9%) and PC (25.9%) (p < 0.05) which did not differ with T7 (p > 0.05). No difference in risk of being laid on was found 1–3 days post-farrowing with all crates closed (p > 0.05). Day 4–6, piglets in T4, experienced higher risk of being laid on compared to PC (IRR = 2.5, p < 0.05), and T7 (IRR = 2.3, p < 0.05). Days 7–15 post-farrowing, risk of piglets dying from being laid on was higher in open crates, T4 and T7, versus PC (T4: IRR = 3.89, T7: IRR = 3.5, p < 0.05). We found higher risk for teat lesions in PC sows at weaning (p < 0.05). With crates open, risk of piglets being laid on increased between 7 days and weaning, but total piglet mortality did not differ and the sow’s risk for teat lesions decreased. Our results, therefore, support opening crates at day 7.