The relationship between activity level, litter performance and motion symmetry in adult sows

Abstract

Lameness and poor limb quality of the sow is, apart from being painful and causing discomfort to the sow, also associated with an increased risk of crushing of piglets. Records of sow activity, as a potential indicator for increased risk of crushing, or increased risk of limb problems, were studied. Records of activity were collected using accelerometers attached to a collar around the neck of the sow. Data was collected on 63 sows at Research centre Lövsta, Uppsala, before and after farrowing. The accelerometers recorded movements over a period of 2.5 days per recording period. Sows were housed individually in farrowing pens with access to straw. Litter size at birth, number of dead piglet and cause of death was recorded by the staff in the stable. A pressure mat was used to investigate how sow gait was affected before and after farrowing. Differences in sow gait parameters were small before and after farrowing. The results show a significant difference in stride velocity between the left and right forelimbs. Further differences were recorded for the stride length of hind limbs. No significant changes were recorded for the weight load distribution between limbs. Activity levels varied over the day with highest activity during the day and lowest at night and in the early morning. Sows with higher levels of activity had a larger proportion of dead piglets, and high levels of activity in total after farrowing was associated with a higher proportion of crushed piglets. However, sows with higher activity levels during the night before farrowing had a lower proportion of crushed piglets. There was no association between activity levels and signs of lameness. In conclusion, activity may serve as an indicator of risk of piglet mortality, but activity in the farrowing pen does not seem to be a useful indicator of lameness.