Claw lesions in lactating sows on commercial farms were associated with postural behavior but not with suboptimal reproductive performance or culling risk

Abstract Claw lesions in lactating sows on 3 commercial farms were assessed in 6 areas of each of a sow's 8 claws to investigate the relationship between claw lesions and stage of lactation. In addition, the relationships between claw lesions and postural behavior, reproductive performance or culling risk were investigated. We used a 5-point score method (0, 1, 2, 3 or 4) for each claw area and overgrown heel was additionally scored. Total sow-lesion score (TSLS) for each sow was obtained by summing the scores for the 6 areas of the 8 claws. The highest claw lesion score for each sow was defined as the highest claw lesion score (HCLS) recorded in the 48 claw areas. We recorded the relative frequency (%) of postural behavior by point sampling at 15-min intervals over a 6 h period. Linear mixed-effects models were used for statistical analyses. Of the 308 sows observed, mean TSLS was 17.3 ± 0.40. Proportions of sows with HCLS 0, 1, 2, 3 and 4 were 0.0, 43.5, 50.6, 4.9 and 1.0%, respectively. The heel area had the highest proportions of claw-lesion score 2 or higher between the 6 areas (P   0.10). There were no differences between TSLS groups for adjusted 21-day litter weight, preweaning mortality or weaning-to-first-mating interval (P > 0.10). No differences were found between HCLS groups for the sow performance (P > 0.10), although sows in the high TSLS group had a higher farrowing percentage than those in the low TSLS group (P   0.10), but sows in the high-TSLS group had the highest relative frequency of lying posture and the lowest frequency of standing posture (P