Fecal Shedding of Mycobacterium avium subsp paratuberculosis in Calves

Implications for Disease Control and Management

Abstract

It is widely accepted that most infections caused by Mycobacterium avium subsp paratuberculosis (MAP) occur in utero or in the neonatal animal. The challenge, however, has been to demonstrate and detect the infection in the young animal, as the onset of clinical signs often takes several years. Earlier detection may allow for more prudent animal management decisions. Two primary objectives of this study are to determine whether fecal shedding of MAP can be detected in naturally infected young animals and if there is a relationship between MAP-shedding cows and fecal shedding in their offspring. This was a longitudinal, prospective study of two years' duration with more than 1,600 samples. It is a cooperative study with MSU, USDA, Michigan Dairy Association, private practitioners and dairy producers.