Is it true that BJD only has a minor effect on production and health at the farm level?
U.S. research has found that BJD causes milk production losses of about 10–20% and high culling rates in dairy herds as the disease progresses. Under Australian conditions, BJD usually has only a minor effect on production and health at the farm level. The prevalence of infection within the herd is usually low and it is uncommon to see animals that appear sick in infected herds. However, the rate of infection can increase and visibly sick animals can become more common if Johne’s disease infection is not controlled in the herd. The prevalence of infection in beef cattle is much lower than in dairy herds but some infected breeding herds have experienced sporadic deaths caused by Johne’s disease over several years, sometimes in animals that have been sold to clients’ herds.
