Financial effect of bovine Johne's disease in beef cattle herds in Australia.

Abstract

OBJECTIVE: To assess the financial effect of programs for controlling bovine Johne's disease (BJD) in beef herds. DESIGN: A spreadsheet simulation model of a self-replacing beef herd in south-eastern Australia selling 400-kg steers at 15 months old. METHODS: The model calculated the monthly cash flow, and net present value (NPV) of cumulative cash flow, over 10 years. Four main control options were compared: (1) a base herd (no action to control the disease), (2) test and cull, and (3) partial and (4) total destocking. It was assumed that BJD was eradicated after 3 and 5 years with total and partial destocking, respectively, and not eradicated with a test and cull program. Scenarios were compared for both commercial and stud enterprises. RESULTS: If there was no discount on the sale price of cattle in commercial herds, deaths from BJD had to exceed 5% before the NPV of partial or total destocking was similar to taking no action to control the disease over a 10-year period. When cattle sales incurred a 10% discount, deaths had to exceed 1% before the destocking strategies would break even after 10 years. CONCLUSION: Control options for BJD should be carefully planned on an individual herd basis, as significant production and financial risks accompany destocking programs. Eradication will only be more profitable in the longer term, compared with living with the disease, when discounts on the sale of stock from infected herds are high. This can occur with the selling of store cattle or breeders. In stud herds, BJD will usually cause the total failure of the business.