Effect of a test and control program for Johne's disease in Victorian beef herds 1992 – 2002

Abstract

The TCP was associated with a marked decline in clinical cases. The similar age distributions of clinical cases and reactors probably meant that testing detected animals for which clinical disease was imminent. Whether the measures used in the TCP were adequate to control the disease in beef herds could not be determined because of the long incubation period of the disease. The relatively high proportion of the reactors investigated that were confirmed as infected provided confidence that the test was continuing to operate at a high specificity. If all unconfirmed reactors were presumed to be uninfected, the minimum specificity of the ELISA was 99.83%. The sensitivity of the ELISA appeared to be very low because of the large number of reactors that were negative at T1 but positive at later tests.

Farm economic impacts of bovine Johne's disease in endemically infected Australian dairy herds

“…The average Victorian dairy herd in 2013–14 milked 262 cows . Assuming a BJD clinical incidence of 1.8% (this was the pre‐enrolment annual clinical incidence for Victorian TCP herds) in infected herds that do not control BJD, we can expect an average of 4.7 clinical cases each year. This estimates the annual losses for the typical endemically infected 262‐cow herd undertaking no control against BJD as $11,748 per annum ($44.84 per milking cow per year).…”

“…The average Victorian dairy herd in 2013-14 milked 262 cows. 15 Assuming a BJD clinical incidence of 1.8% (this was the preenrolment annual clinical incidence for Victorian TCP herds 16 Table 6.…”

“…Annual mortality rates had to exceed 1.0% per annum with a 10% discount on price received for cattle sales required to justify destocking‐based eradication program. The prevalence of infected herds and the within‐herd prevalence of BJD in infected dairy herds is greater than occurs in the beef industry and the production and profit of dairy cows is significantly different to beef herds, preventing valid extension of the conclusions of the 2012 beef study to Australian dairy herds.…”

Genotype profiles of Mycobacterium avium subspecies paratuberculosis isolates recovered from animals, commercial milk, and human beings in North India

“…Developed countries have control programs in place to reduce the prevalence of the disease. [4][5][6] Information on the prevalence of MAP genotypes in India is not currently available.…”