Johne's disease is chronic intestinal disease which is found in many dairy and beef herds. While as few as 1-5% of cows in any year will show clinical signs of scour or wasting, a greater proportion of the herd will be affected and suffer reduced output.
Key facts on Johne's:
- 80% of cows become infected within the first month of life.
- Ingesting faeces is the most important route of transmission, but transmission also occurs across the placenta and through drinking infected colostrum and milk.
- Johne's can last up to a year in slurry on pasture. Infected cows shed bacteria for years before showing clinical signs, highlighting the need for testing.
- Usually introduced into herd through purchased breeding stock (including bulls).
Animals with Johne's are:
- Twice as likely to have milk yields 25% below their adjusted herd average.
- More likely to be culled earlier.
- Twice as likely to have a cell count >200,000 and be affected by other conditions including chronic mastitis, lameness and high somatic cell counts.
Download Gethin's May Newsletter to find out more about testing options, transmission routes and Johne's ACTION. The latest newsletter also advises of changes to NMR HerdWise reporting and has information on our Medicine Handling course.