Survival and Risk Factors Associated with Claw Lesions of Female Pigsin Farrowing Crates on a Large Commercial Farm

Abstract

The objectives of the present study were to compare the occurrence of claw lesions in late-gestating pigs and lactating sows on a commercial farm and to investigate the relationships between claw lesions and parity, age of gilts at first mating, and survival probability. A farrow-to-finish farm was visited six times from 2007 through 2008 to observe the claw lesions of late-gestating pigs and lactating sows fed in farrowing crates in lactation barns. We used a four-point score method (0, 1, 2, or 3) for each of the seven claw areas in each of the eight claws of a female pig. The total pig-lesion score (TPLS) for each female pig was obtained by summing the scores of all the areas and claws in a pig. Two TPLS groups were formed on the basis of the upper 10th percentile of the TPLS : low (0 to 5) or high (6 or higher). Linear mixed-effects models were performed for statistical analyses. A Cox proportional hazards model was used to obtain the survival probability. Of 629 female pigs studied in the farrowing crates, 64.4% had one or more claw lesions. Mean TPLS (±SEM) of the female pigs was 2.6±0.15. Late-gestating pigs had higher TPLS than lactating sows (4.1±0.42 vs. 2.1±0.14 ; P<0.05). Moreover, TPLS was higher in later parity in both the late-gestating pigs and lactating sows (P<0.05). However, there were no associations between the age of gilts at first mating and TPLS in late-gestating pigs (P=0.08) or lactating sows (P>0.10). Additionally, no associations were found between survival probability and TPLS in either the late-gestating pigs or lactating sows (P>0.10). To facilitate animal well-being, we recommend that swine producers frequently examine claws of females in farrowing crates to identify females with severe claw lesions.