LANSING, Mich. – Offspring purchased from a Saginaw (Michigan) County dairy farm that tested positive for bovine tuberculosis also tested positive for the disease, the Michigan Department of Agriculture and Rural Development (MDARD) reported. The animals were traced to farms in Midland and Gratiot counties, the agency said.

In March, a Saginaw County dairy farm was discovered to be bovine TB positive when a cull cow with lesions went to slaughter. Inspectors with USDA's Food Safety Inspection Service removed the cow and sent it for laboratory testing.

The state quarantined the farm and immediately started an investigation into where any deacon calves or heifers may have gone. The search uncovered two small beef herds — one in Midland County and another in Gratiot County, both raising deacon calves from the affected Saginaw County herd. MDARD said cattle with a skin test response were euthanized and submitted to Michigan State Univ.'s Diagnostic Center for Population and Animal Health (DCPAH) for laboratory examination. Tissue samples were then sent to the National Veterinary Services Laboratories (NVSL) in Ames, Iowa, which reported the animals were positive for bovine TB.

"Michigan is fortunate to have regulatory veterinarians knowledgeable on trace testing and epidemiological investigations," said Jamie Clover Adams, MDARD Director. "And, thanks to years of hard work, MDARD is well-prepared to handle this investigation."

MDARD plans to test cattle for TB in two additional special surveillance areas in 10-mile circles around the two affected farms. The agency will notify cattle producers directly if they lie within the 10-mile circles. Those producers can request disease control permits to remove deer as part of the Michigan Department of Natural Resources' (DNR) disease surveillance effort in these circles.