title: Farm economic impacts of bovine Johne's disease in endemically infected Australian dairy herds.
abstract: OBJECTIVE
  To determine the farm economic impact of bovine Johne's disease (BJD) infection and controls in commercial Victorian dairy herds.
  
  
  METHODS
  Benefit-cost analysis of BJD and various control methods in a Victorian dairy herd.
  
  
  RESULTS
  Farm losses from BJD occurred from clinical disease. Clinical cases occur on average in 5-year-old cows, resulting in losses of A$1895 in the year of culling and A$221 in the year preceding culling, giving a total loss of A$2116. Early removal also resulted in loss of future profit equating to A$375 per year. This is the annualised value of foregone future income and costs expressed as a net present value (NPV). The total loss from removal of a clinical case was estimated as A$2491. The average clinical incidence in infected dairy herds prior to entry into the Victorian Bovine Johne's Test-and-Control Program (TCP) was 1.8% and the average Victorian dairy herd size was 262 cows in 2013-14, resulting in annual losses of 4.7 clinical cases if infected and implementing no BJD control. Farm annual loss of profit was estimated as A$11,748 ($44.84 per cow/year). Control of BJD using vaccination, test-and-cull or combined approaches was economical but the cost of implementation in initial years would exceed disease costs. Vaccination-based control provided minimal long-term losses and was the most cost-effective control over a 10-year planning horizon.
  
  
  CONCLUSIONS
  Endemic BJD resulted in modest but persistent losses in typical infected dairy herds. Control of disease using test-and-cull, vaccination or combined test-and-cull with vaccination was cost-effective.
authors.affiliation: Herd Health Pty Ltd, 65 Beet Road, Maffra, Victoria, 3860, Australia. richard@herdhealth.com.au.
authors.forename: R W
authors.initials: RW
authors.lastname: Shephard
authors.affiliation: Scott Williams Consulting, Creswick, VIC, Australia.
authors.forename: S H
authors.initials: SH
authors.lastname: Williams
authors.affiliation: SDBbio, Gundaroo, NSW, Australia.
authors.forename: S D
authors.initials: SD
authors.lastname: Beckett
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000191:economics* / Q000453:epidemiology / Q000382:microbiology; D003365:Costs and Cost Analysis / Q000706:statistics & numerical data; D003612:Dairying / Q000191:economics*; D005260:Female; D010283:Paratuberculosis / Q000191:economics* / Q000453:epidemiology; D014739:Victoria / Q000453:epidemiology
keywords: bovine Johne's disease; dairy cattle; economics; modelling