Johne’s Disease: A Retrospective Study of Vaccinated Herds in Great Britain

Abstract

SUMMARY The use of Johne’s disease vaccine in cattle in Great Britain since its introduction in 1964 is briefly reviewed. In 1975 the vaccine was being used in 462 herds of which 68 (14·8%) were beef herds, 381 (82·5%) dairy and 13 (2·7%) were mixed dairy and beef herds. This represented a vaccination rate of three herds per 1000 herds containing adult dairy or beef cattle in Great Britain. The vaccine has been used in herds with relatively high rates of disease and particularly in dairy herds. A retrospective study of disease incidence in 231 cattle herds, in which all calves had been vaccinated over a period of at least four years and which had remained closed with no changes in breed or herd type, indicated that freedom from disease was achieved after an average of four years. Clinical cases occurred in 9·7% of herds in the tenth year following the start of vaccination. The number of years to freedom from disease was apparently influenced by management practices; provision of piped water supplies and the culling of offspring of clinical cases being beneficial. The incidence of disease prevaccination, herd size and breed were not found to affect the time for herds to become free of clinical disease.