Preliminary study on the potential cost at slaughter of OJD vaccination site lesions to the Australian sheep industry.

Abstract

This report presents the results of a pilot project to predict the risk of discounts being applied in Australia due to OJD vaccination site lesions as vaccine use expands. This includes a review of discounting in New Zealand as well as a preliminary survey of the prevalence of lesions and actual discounts applied to slaughtered vaccinates in Australia. Information from New Zealand suggests that the greatest discounts are applied to trimmed high value lamb carcases that are destined for export in whole carcase form as a result of downgrading to a lower quality grade. In Australia the greatest risk of discounting is likely to be in purebred merino lambs sold into the prime lamb market, but the low proportion exported as carcases would limit the discount applied. The prevalence of lesions observed was 18% for mutton and 65% for lamb carcases. The value of the trim removed was insignificant, the labour cost of its removal was nil and no carcase was downgraded to a lower value grade. However this study was conducted at a time of low sheep supply in carcases vaccinated at the recommended site and caution should be exercised in extrapolating these results to oversupplied market situations or in sheep vaccinated at alternate sites.