Rib Fractures in Lambs in South Australia

The frequent occurrence of rib fractures in slaughtered lambs results in significant economic loss to producers and processors in South Australia and raises concerns about the welfare of the animals. The prevalence of rib fractures became evident through the Enhanced Abattoir Surveillance (EAS) program introduced in 2007. The present study aimed to investigate the association between rib fracture prevalence in lambs at slaughter and their nutrition and management on the farm of origin. The slaughter of 30,055 lambs from 60 farms was monitored at a South Australian abattoir in November 2016. Rib fracture prevalence was 4% (range 0 - 18% per consignment), with all consignments of more than 240 lambs having at least one with fractured ribs. Traceback investigation on 56 of the 60 farms suggests that rib fractures most probably occur during routine husbandry procedures and, based on soil mineral analysis, are associated with calcium inadequacy. There was substantial variation between lines of lambs from different farms, and factors contributing to the differences included line size, region, and soil characteristics, including available calcium. There is a need to modify sheep husbandry and management practices to improve sheep welfare and reduce the cost of rib fractures to the sheep industry.