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Principal Investigator: Dr. Ynte Schukken
Contact Information: E-mail: yhs2@cornell.edu - Phone: 607-255-8202
Sponsor: USDA-University of Minnesota (Subcontract Agreement)
Grant Number: Q6286224401 (DP7)
Title: Calf-to-Calf Transmission of Mycobacterium Avium subspp. Paratuberculosis (MAP) on Commercial Dairy Farms
Annual Direct Cost: $19,237
Project Period: 04/15/06-04/14/07
Summary: It is estimated that the US dairy industry alone loses between $200 and $250 million annually as a result of Johne's disease. In addition to this loss, the potential link to the human disease Crohn's has focused the US cattle industry on research to provide effective Johne's prevention strategies on the farm. As of yet efforts have centered on preventing cow-to-calf infection by testing and culling high shedding dams and preventing contact with young calves. However, this has not resulted in an elimination of the infection from farms. In this study we aim to address the contribution of calf-to-calf contact on Johne's transmission. Based on experimental studies it is known that this transmission between calves is possible. Simulation modeling has shown that calf-to-calf transmission may contribute to endemically infected herds. We therefore intend to study whether calf-to-calf transmission is a real concern in a commercial dairy environment. A cohort of calves selected based on high risk for exposure to a calf born from a high shedding dam will be followed by means of fecal culture to determine shedding status during the first year of life. This cohort will be intensively sampled to ensure that short duration periods of shedding will be detected. Positive samples will then be strain typed to aid in determining whether infectious transmission is occurring between calves, and to distinguish between pass through and active infection. If transmission does indeed occur among calves on farms, we need to dramatically change our preventative programs to prevent young infected animals from spreading Johne's to their herd mates.
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