It’s estimated that one out of 10 cows going through a livestock auction facility has Johne’s disease (pronounced “Yo-nees”) – and a vast majority of producers have no idea the animals they sell are infected with the disease.
Johne’s disease experts maintain that dairy and beef cows are leaving herds way too fast – before they are tested for Johne’s disease. They note producers who have culled one or more animals for unresponsive chronic diarrhea combined with reduced milk production and thin condition should suspect and test for Johne’s disease.
“Johne’s disease is a slow and progressive bacterial disease of the intestinal tract that affects ruminants and is caused by the bacterium Mycobacterium avium paratuberculosis,” states Dr. Michael Carter, National Johne’s Disease Control Program Coordinator, National Center for Animal Health Programs, USDA-APHIS-VS. “Infected animals can shed large numbers of the disease-causing bacteria in their feces, leading to contamination of feed and water sources without ever showing clinical signs. Infected animals can also shed the bacteria in their colostrum and milk, and infected dams can pass the disease on to their offspring.”
Johne’s disease is estimated to be present in 68% of U.S. dairy operations and in eight out of 100 U.S. beef herds. A 1996 National Animal Health Monitoring Systems study found that dairy herds with a low Johne’s disease clinical cull rate experience an average loss of $40/cow while herds with a high Johne’s disease clinical cull rate have on average a $227/cow loss, with losses resulting from reduced milk production, early culling and poor body condition at culling. Although a dollar amount has not be estimated for Johne’s disease in beef herds, Johne’s-infected beef cows are known to produce less milk resulting in lighter calves at weaning and can be slower to breed back.
To obtain your copy of Johne’s prevention and control brochure, or to learn more about Johne’s disease, visit online or call the National Institute for Animal Agriculture (NIAA) at 270-782-9798.