Using an epidemiological framework and bovine spongiform encephalopathy investigation questionnaire to investigate suspect bovine spongiform encephalopathy cases: an example from a bovine spongiform encephalopathy case in Ireland in 2015

Findings in cattle consigned to Victorian knackeries between 2009 and 2018

OBJECTIVE

To describe the causes of death or culling in cattle in Victoria, Australia, through surveillance at knackeries.

METHODS

Data were collected from 2797 adult cattle consigned to four Victorian knackeries over a 10-year period (2009-2018, inclusive). Cattle were sampled either at the point of collection or at a knackery. A single best-fit diagnosis was assigned to each case to describe the cause of loss.

RESULTS

Sampled cattle were predominantly female dairy cattle originating from the three main dairying regions in Victoria. The most commonly diagnosed conditions were calving paralysis (6.8%), followed by mastitis (6.4%), hypocalcaemia (6.4%) and dystocia (5.9%). "Unknown" accounted for 24.2% of the cattle examined.

CONCLUSION

This study provides a unique insight into the causes of death and culling in cattle consigned to Victorian knackeries. The periparturient period was identified as a high risk period for knackery consignment in adult female cattle.