Environmental Distribution of Mycobacterium avium ssp. paratuberculosis on Cow-Calf Farms with Clinical Johne's Disease in Western Canada

Abstract

Johne's disease, caused by Mycobacterium avium ssp. paratuberculosis (Map), is a progressive and debilitating disease of cattle. The main modes of transmission include direct contact with infectious manure or through exposure through colostrum. Calves from cow-calf herds cannot be isolated immediately after birth and so control efforts must reduce exposure to the bacteria from the environment. Environmental contamination on cow-calf farms is important to understand because if not adequately dealt with, disease control may not be achieved. Environmental testing could also reduce the cost of a herd test if it could replace animal testing in control programs. This study improves the understanding of environmental contamination of Map in cow-calf herds.