Submitted to: International Workshop on Tuberculosis in Animals
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/1999
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Free-ranging white-tailed deer in a six county region of northeast Michigan have recently been identified as a wildlife reservoir of Mycobacterium bovis. Other countries with a wildlife reservoir of tuberculosis have not been able to eradicate the disease from domestic livestock. In 1998 and 1999, tuberculosis was confirmed in three herds of beef cattle in this region of Michigan. Results of DNA fingerprinting indicate that the cattle were infected with the same strain of M. bovis that was isolated from the deer. Although the source of M. bovis that infected the cattle is not known, it is thought that they became infected through direct or indirect contact with deer that were shedding the organisms. The purpose of the present study was to determine if cattle can become infected with M. bovis by ingestion of feed that has been contaminated by infected deer shedding the organisms. Twelve white-tailed deer were inoculated by the intratonsillar route with approximately 7 x 10**5 CFU of M. bovis. After two weeks, nine calves were introduced into the barn with the deer. Deer were offered excess feed and allowed access to it overnight. Deer then were moved to another pen and calves were given access to the feed. This process was repeated daily. Oral, nasal, and rectal swab samples were collected monthly to monitor animals for shedding of M. bovis and blood samples were collected to monitor immune responses. All animals also were skin tested at approximately 90-day intervals. Preliminary results of this study will be presented.