By Nicole Heslip

After 20 years of battling bovine tuberculosis outbreaks in Michigan, this past year the Michigan Department of Agriculture and Rural Development is reporting an uptick in confirmed cases for the first time in a decade, with the latest detected in western Michigan.

In Mid-March, MDARD confirmed a 2-year-old steer from Newago County was positive for bovine TB after inspection during processing, adding to the two herds in December that were reported and bringing the state’s total number of herds confirmed positive for bovine TB to 68 since 1998. Currently, Alcona, Alpena, Montmorency and Oscoda counties are in a Modified Accredited Zone while the remaining 79 counties in Michigan are TB-free. (See “Herd in Newago is positive” below.)

Michigan state veterinarian Dr. James Averill says the department’s hypothesis is that the prevalence of bovine TB has increased in the wild deer population, which has increased the risk of it spreading to the cattle herd. “Recent harsh winters, which are hard on the free-ranging deer herd’s immunity, may have led to more bovine TB infections in deer and additionally forced more deer to go on farms to look for food,” he says. Together, these factors would increase the risk of cattle herds becoming infected with bovine TB if not tightly protected. When the deer disperse once it becomes warmer, there’s more potential for cattle herds to become infected. Since the spring of last year, MDARD has confirmed seven cases of bovine TB, up from about three on average in recent years.

When a herd is confirmed with bovine TB, an epidemiological investigation team is sent out to the farm to find ways the infection could have possibly occurred. Phil Durst, Michigan State University Extension dairy and beef educator, is part of the team that visits farms in northeast Michigan. Durst says the group is specifically looking for how deer may have left bacteria that cattle consumed. “Even though the percent of infected deer is relatively low, ranging from at least 1.5% to 2.5% of the deer within that four-county area, that’s still a significant number of infected deer because there’s upward of 100,000 deer in the area,” he explains.

Farmers in the region need to consider every deer as potentially infected, and Durst recommends doing everything possible to protect cattle, feed sources and water. “Farms there are taking many steps to reduce the risk of disease getting to the cattle,” says Durst. Today that includes more fencing of feed supplies and even farmsteads, but Durst says mitigation efforts need to go beyond fencing. “Fencing does not reduce the risk of the number of infected deer; fencing may protect cattle herds but it does not change the number of infected deer.” Durst believes more work needs to be done to reduce the ways deer can thrive around farms, which he says needs to include a combination of reducing deer numbers and attractants around farms.

Michigan ramps up mitigation efforts
There might be more resources on the way as Gov. Rick Snyder’s 2018 budget proposal includes a one-time ask of $1 million to support bovine TB prevention efforts. Cattle producers in the northern Lower Peninsula are currently required to meet minimum wildlife risk mitigation standards to sell live animals, but according to Averill, it may not be enough for farms in the core TB area. “There’s about 120 cattle herds in the heart of the four counties, and we want to have one-on-one conversations with them to evaluate their biosecurity practices,” he says.

The department plans to use the funds to enhance wildlife risk mitigation for farmers in high-risk areas to provide farmers greater protection. “We want to use this money in this request to help cost-share and help implement some further infrastructure they may need, whether it’s high fencing to protect their hay or it’s high fencing for a feeding area or if it’s some additional type of three-dimensional pasture fencing,” he says.

Bovine TB continues to be the No. 1 priority program for Averill and his staff. “By doing this enhanced wildlife risk mitigation, we will reduce the number of herds becoming infected and move closer to TB-free,” he says.

Rep. Joe Hune of Hamburg, chairman of the Michigan Senate Agriculture Committee, says with herds continuing to be confirmed positive for bovine TB, something needs to be done. Hune believes hopefully one day Michigan will be free of bovine TB, but it’s a long, challenging process. “That’s an issue that we’ve either got to do some legislation in the time to come or at least closely monitor it to make certain that’s taken care of in the future,” he says.

According to Averill, it’s hard to put an overall economic number on the response to bovine TB. The state has spent just over $150 million. The federal government has also put additional resources in excess of $75 million over the years. The department has spent over $1 million on cost-share programs for feed storage via hoop barns and fences, which includes 79 hoop barns and seven fenced feed storage enclosures. In addition, Averill says, “There was approximately $1.5 million in funds available through NRCS [Natural Resources Conservation Service] to northeast Michigan producers for conservation measures which, in turn, helped reduce the risk of cattle and deer interactions.”

To better protect feed supplies and cattle housing and feeding areas, Durst says more investment is required. However, the current economic situation for both dairy and beef cattle producers is making it tough to even cover a portion of the cost. Recently, Durst says, the farmer’s portion of a cost-share project could be provided as in-kind labor.

The cost of reducing deer numbers is comparatively much lower, according to Durst. While there are issues of wild deer on privately owned lands, there are opportunities to change the dynamic in the wild-deer herd. Durst says, “No matter how low the population of deer would become, it would return to a level that can be supported by the habitat and food sources, and it would return as a healthier herd.”

According to Durst, this long-fought battle with bovine TB has had a ripple effect on the entire community. He says, “With this factor of TB hanging over farms, there’s been a lack of growth of the industry, there’s been a lack of growth on individual farms, and that limits the economic viability of industry in the area. As a result, there are negative impacts on the secondary business in the community that depends on agricultural production. There is no doubt that in northeast Michigan the disease has had an economic impact to the communities; the exact cost is unknown.”

Durst believes a community working together is the best way to prevent the disease. “It takes cattle producers, crop farmers, hunters and landowners all working together because they share a concern about the health of the deer herd and the health of the cattle herds,” Durst says. By working together, he urges, there is greater potential to protect farms. “No matter where you are in the state, we cannot ignore this disease,” stresses Durst.

Heslip works as the Michigan anchor/reporter for Brownfield Ag News.

Herd in Newago is positive

On March 13, the Michigan Department of Agriculture confirmed a 2-year-old steer from Newago County tested positive for bovine tuberculosis after inspection during processing. The department identified the Newago Country farm that sent the steer to slaughter using the animal’s radio frequency identification. Through genome sequencing, officials have determined the steer was most likely exposed to white-tailed deer in northeastern Lower Michigan with the disease. Farms within a 3-mile surveillance area are being tested for bovine TB.

At the beginning of December last year, the Michigan Department of Agriculture confirmed two cases of bovine TB in northern Michigan. A large dairy herd in Alpena County and a large beef herd in Montmorency County tested positive during recent routine testing. These were the 67th and 68th confirmed herds in Michigan since 1998.

Both Alpena and Montmorency counties are in a Modified Accredited Zone where four northern Michigan counties regularly test for TB annually and before transporting animals off of farms.