Lameness in sows is an emerging disease condition with major effects on animal
welfare and economics. Yet the direct impact on reproduction results remains unclear.
The present field study investigated the impact of lameness and claw lesions
throughout the reproductive cycle on (re)production results of sows. In five farms, a
total of 491 group-housed sows were followed up for a period of one reproductive
cycle. Sows were assessed for lameness every time they were moved to another area in
the farm. Claw lesions were scored at the beginning and at the end of the cycle.
Reproduction results included the number of live-born piglets, stillborn piglets,
mummified fetuses and crushed piglets, weaning-to-oestrus interval and the presence
of sows not showing oestrus post weaning, returning to service and aborting. Sows
that left the group were recorded and the reason was noted. A mean prevalence of
lameness of 5.9% was found, although it depended on the time in the productive cycle.
The highest percentage of lame sows (8.1%) was found when sows were moved from the
post-weaning to the gestation stable. No significant associations were found between
lameness and reproduction parameters with the exception of the effect on mummified
foetuses. Wall cracks, white line lesions, heel lesions and skin lesions did have an
effect on farrowing performance. Of all sows, 22% left the group throughout the
study, and almost half of these sows were removed from the farm. Lameness was the
second most important reason for culling. Sows culled because of lameness were
significantly younger compared with sows culled for other reasons (parity: 2.6 ± 1.3
v. 4.0 ± 1.8). In conclusion, the present results indicate that
lameness mainly affects farm productivity indirectly through its effect on sow
longevity, whereas claw lesions directly affect some reproductive parameters. The
high percentage of lame sows in the insemination stable indicate that risk factor
studies should not only focus on the gestation stable, but also on housing conditions
in the insemination stable.