Thesis Title: A study of Mycobacterium avium subsp. paratuberculosis (MAP) shedding patterns in feces, milk, and colostrum and the development of methods to detect the bacterium in colostrum more efficiently. 

 

Description of Project: 

We will identify approximately thirty MAP infected cows using data from a companion project. We will then monitor monthly these animals’ MAP shedding patterns via fecal and milk culture and PCR, and note any association of MAP shedding to season and days in milk. MAP shedding in colostrum will also be followed via colostrum culture and PCR for these cows, as well as approximately sixty others with high milk ELISA results at dry off. Using the colostrum data, we will assess a novel macrophage protein marker-based diagnostic test. We will also study the variability in milk ELISA results monthly by comparing results from MAP positive cows with those of a matched MAP negative herdmate. Our first goal is to gain a greater understanding of MAP shedding in relation to lactation stage in order to find the optimal time for diagnostic tests for management and critical control protocols. Our second goal is to assess a pathogen or protein marker based molecular colostrum test that may lead to a cow-side colostrum test for farm based control programs.