Clinical signs of Johne's disease are persistent or intermittent diarrhea, weight loss progressing to emaciation and death 7 .
Economic loss is compounded by decreased milk production and poor reproductive performance.
Cattle infected with BLV become virus carriers for life because viral sequences are incorporated into the host cell genome 1,5 . Cattle develop antibodies but the virus is not cleared 2 . This test has been shown to have high specificity and sensitivity 6 . Concurrent infection with M. paratuberculosis was disclosed by mycobacteriologic examination 8 . There were 339 adult cows in the 5 herds receiving vaccine and 450 adult cows in the nonvaccinated herds.