A Study of Biological and Economic Impact of OJD in affected Sheep Flocks in NSW

Summary

This study provides industry with factual information about the impact of OJD on farms in southern Australia. This is needed to assess the magnitude of the OJD problem and to direct control and management programs. On 12 farms, the average OJD mortality rate based on inventory records was 6.2% (range 2.1% to 17.5%), more than twice the accepted mortality rate (from all causes) for Australian sheep flocks. OJD losses accounted on average for 70% (range 17% to 100%) of the estimated total economic loss associated with sheep deaths over this 12-month study. In addition this project confirmed that prevalence based on pooled faecal culture (PFC) could be used as an indicator of OJD mortality level and provided support for further investigation of several risk factors in a future study focused on a specific sheep cohort and involving a larger number of farms. We recommend that producers, through industry extension activities, be informed of the substantial losses associated with OJD and be encouraged to implement control measures on their farms. We also recommend the development of a model to predict on-farm economic impact of OJD.