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 < 0.05). There were more claw-lesion scores of 2, 3, and 4 in the hind limbs of lateral claws than in the front limbs (P < 0.05). High TSLS or HCLS was not related to the stage of lactation and no differences were found between HCLS groups or TSLS groups for overall culling risk after weaning (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 < 0.05). There were no differences between HCLS groups for postural behavior (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 < 0.05). In summary, claw lesions in lactating sows were not related to negative reproductive performance and culling risk, but there was a relationship with postural behavior.