Controlling Johne's Disease

Controlling Johne's Disease in Minnesota Dairy Herds

Johne's disease is economically important to dairy farms, but often not noticed

• Many infected herds lose over $200 per cow in inventory per year (USDA-APHIS study), mostly due to premature culling and lost milk production
• The long incubation period (2-6 years from infection to disease onset) masks the impact of disease to producers, though infected cows can transmit infection to other cattle before showing signs of disease and/or testing positive for Johne's.

Johne's disease can be controlled on the dairy farm

• Most herds are infected though purchase of infected cattle
• On infected farms, transmission occurs primarily through fecal-oral routes, especially to susceptible young heifer calves
• Disease control involves preventing heifer calves from exposure to manure from adult cows (with special focus on calving area and segregated heifer rearing)

The first step in control of Johne's disease is for producers to identify whether their dairy herds are infected.

To identify if cattle are infected, the Minnesota Board of Animal Health will:

• Test a random sample of 30 cows in a producer's herd to identify herd infection status (The BAH pays for lab costs of tests).
• If herd tests positive, BAH district veterinarian will visit the farm and evaluate the key risks for spreading infection on the farm.
• After the Risk Assessment is performed, a herd plan will be developed with the producer's veterinarian, and the district veterinarian. The BAH will test up to 200 cows in a producer's herd each year (BAH pay for lab costs of tests) to monitor infection.

Contacts:

Minnesota Board of Animal Health phone: 651-296-2942