PSV-6 Assessment of lameness in gilts and barrows using gait score, force-plate, hoof hardness and hoof lesions

Abstract

Abstract Lameness in gilts and sows has an economic impact on pig production and is a major welfare concern. The objective of the present project was to evaluate and quantify lameness in pigs. The following methods were compared to visual gait scoring: force-plate, hoof hardness and hoof lesions. Eight barrows and seven gilts (114 ± 15 kg) were selected using visual gait scoring (0-4, 4 most severe). From this group there were 4-0’s, 4-1’s, 5-2’s, and 2-3’s. Factorial analyses, (site: front vs rear) and lameness score (0-3) and their interaction was used to evaluate effect of treatment. Consistent with published literature, rear legs were more affected by lameness than front legs (73% rear, 27% front). Only two categories for hoof lesions (white line lesion and heel erosion) were prevalent in this population. White line lesion severity increased with increasing lameness score and differed between site (P < 0.05). In contrast with literature, more white line lesions were prevalent in front vs rear. Hoof hardness was scored at 5 locations on the bottom of the hoof. At the toe tip only, there was a trend (P = 0.052) for hoof hardness to decrease with increasing lameness score, but no effect of site (P = 0.39) or interaction. Among force-plate measurements, there was a significant effect of lameness (P < 0.05) for maximum force, range (95th percentile-5th percentile), standard deviation of force, amplitude of weight-bearing (average of all positive peaks), amplitude of weight-removing (average of all negative peaks), but no significant effect observed for average force, weight shift (# of peaks/min) or contralateral ratio. On average, more weight was applied to front vs rear [30.4 vs 19.6%; (P < 0.05)]. Although further validation is warranted, these results indicate that these objective measures of lameness were sensitive enough to detect differences between lame vs non-lame pigs.