Evaluation of two ELISA's for the detection of Mycobacterium avium paratuberculosis antibodies in milk samples from dairy cattle

Johne's disease has become the focus of increasing attention in the UK over the past few years. Mycobacterium avium paratuberculosis (MAP) infection is reported to be widespread in dairy cattle in both the US and Europe, and a postal survey conducted in 1995 reported that 17% of dairy herds in England and Wales had had at least one case of Johne's disease in the past. The objective of this study was to identify an accurate and cost effective test to detect MAP infection in dairy herds. Currently, the tests available in the UK include faecal culture and serology and both are expensive and time consuming to perform. The initial aim of the study was to determine whether commercially available ELISA tests for MAP antibody in serum could be used to test milk samples from individual cows. Subsequently, if it was shown that there was a high correlation between the test results for sera and milk, the use of these ELISA's to test bulk-milk samples would be evaluated