Johnes disease is widespread in New Zealand, with an estimated 60% of dairy herds infected. Caused by the bacteria Mycobacterium avium subspecies paratuberculosis (MAP), Johnes is a chronic and contagious wasting disease of ruminants (think cattle, sheep and deer). Given Johnes positive dairy cows have been shown to produce 15% less milk, the disease has a significant but often difficult to see economic impact on farms.
MadCowNov2024Newsletter – November 2024
