Within a 10-day window between May 6-15, Michigan had nine dairy milking herds test positive for highly pathogenic avian influenza, according to the Michigan Department of Agriculture and Rural Development website.

Since the first herd was identified March 29, there have been 16 total milking herds affected by the virus — the most in the country and three more than Texas, where the first HPAI-positive dairy herd was identified.

The disease, generally carried by wild birds such as ducks and geese, causes cows to have de­creased lactation, low appetite and other symptoms, but it does not require them to be euthanized. Cows are removed from the milking herd and treated, and milk is appropriately discarded. Pasteurizing milk, which kills bacteria and viruses, ensures the safety of milk.

While no cows have died from the virus, the disease is lethal to birds, and Michigan has had an influx of cases in poultry in recent months. Avian flu is highly contagious.

Michigan, a net exporter of eggs and the seventh-largest egg-producing state in the country, has had 6,841,990 birds affected by avian flu, including 10 commercial operations and 26 backyard flocks.

While Michigan has been a hot spot for avian flu recently, several states have had more poultry casualties over the course of the outbreak. Iowa has the most, with 31 commercial operations and 20 backyard flocks testing positive with 18.8 million birds. Ohio has seven commercial and 10 backyard operations testing positive with 9.6 million birds.

Egg-laying operations shutter

Michigan had its first commercial poultry operation test positive on May 10, 2022, with 35,100 tur­keys. Two more commercial turkey operations were affected in December 2023. On April 3, a commercial flock of almost 2 million egg-laying hens in Ionia County was confirmed positive at Herbruck’s Poultry Ranch, the largest poultry farm in the state.

Six days later, another location of Herbruck’s in that same county also tested positive with just over 2 million birds.

A third Herbruck's egg-laying facility in Ionia County was confirmed positive April 16, housing 2,422,700 birds. In total, the disease has impacted three Michigan Herbruck's locations.

As the company goes through depopulation, disinfection, inspection and repopulation, it announced this week in a WARN (Worker Adjustment and Retraining Notifications) letter to the Michigan Department of Labor and Economic Opportunity, Workforce Development, it intends to lay off about 400 of its 1,200-person workforce.

In a statement, Greg Herbruck, CEO of Herbruck’s Poultry Ranch, said, “In the face of ongoing efforts to address the detection of highly pathogenic avian influenza alongside state and federal regulators, Herbruck’s has reached the difficult decision to conduct layoffs at the affected facilities where work is not available. We expect this to largely be temporary, as we plan to rehire many positions as we work to repopulate our facilities and continue egg production as safely and quickly as possible. We understand this is a stressful situation for our team members, and we are working with our state partners to provide them with resources, answer questions and assist in their individual family situations.” 

Since the start of the outbreak on Feb. 8, 2020, 90.89 million birds have been affected in the U.S. HPAI has been detected in a total of 1,138 flocks in 48 states. Of those, 486 flocks have been commercial, and 652 flocks have been backyard.

Dairy impact in 9 counties

The first Michigan herd testing positive received asymptomatic animals from the infected Texas herd, according to USDA’s National Veterinary Services Laboratories (NVSL).

In response, the federal government now requires testing of dairy cattle for HPAI, more specifically avian influenza (type A H5N1), before being transported to another state.

Tim Boring, Michigan’s director of agriculture and rural development, says pro­ducers must immediately implement robust biosecurity practices and create emergency preparedness plans. He also issued an emer­gency order requiring all lactating dairy cattle, and those in the last two months of pregnancy, to be prohibited from being exhibited until there are no new cases of HPAI in dairy cattle in the state for at least 60 consecutive days. No dairy cattle of any age from an infected premises may be ex­hibited until further notice.

All exhibitions or expositions of poultry are prohibited until such time that there are no new cases of HPAI in domestic poultry in the state of for at least 30 consecutive days.

Wild migratory birds are believed to be the source of infection. However, the spread of the illness among the Michigan herd also indicates that HPAI transmission between cattle cannot be ruled out, NVSL reports.

“This virus does not stop at county or state lines, which is why we must all be on high alert,” Boring said in a news release. “This news is unfortunate and upsetting for our poultry and dairy farming families and communities.”

The infected cattle herds are located in central and west Michigan in nine counties: Ottawa, Allegan, Barry, Ionia, Clinton, Ingham, Montcalm, Gratiot and Isabella counties.

USDA financial assistance

USDA is providing assistance for producers with H5N1-affected premises to improve on-site biosecurity and is offering financial assistance, including funds to:

Protect against the potential for spread between human and animals. Up to $2,000 per affected premises per month is available for producers who supply PPE to employees or provide outerwear uniform laundering, and for producers of affected herds who facilitate the participation of their workers in a USDA/CDC workplace and farmworker study.

Support producers in biosecurity planning and implementation. Provide support (up to $1,500 per affected premises) to develop biosecurity plans based on existing secure milk supply plans. This includes recommended enhanced biosecurity for individuals that frequently move between dairy farms — milk haulers, veterinarians, feed trucks, AI technicians, etc. In addition, USDA will provide a $100 payment to producers who purchase and use an in-line sampler for their milk system.

Heat treatment to dispose of milk in a biosecure fashion. In accordance with standards set by FDA, the treatment effectively inactivates the virus in milk. If a producer establishes a system to heat-treat all waste milk before disposal, USDA will pay the producer up to $2,000 per affected premises per month.

Reimburse producers for veterinarian costs associated with confirmed positive H5N1 premises. Veterinary costs are eligible to be covered from the initial date of positive confirmation at NVSL for that farm, up to $10,000 per affected premises.

Offset shipping costs for influenza A testing at laboratories in the National Animal Health Laboratory Network. USDA will pay shipping costs, not to exceed $50 per shipment for up to two shipments per month for each affected premises.

Taken together, these tools represent a value of up to $28,000 per premises to support increased biosecurity activities over the next 120 days.

Additional information

To learn more about USDA’s response to H5N1 in dairy cattle, visit aphis.usda.gov.

To learn more about CDC’s response to H5N1, visit cdc.gov.

To learn more about FDA’s response to H5N1, visit fda.gov.