DES MOINES, Iowa (AP) — The U.S. Department of Agriculture says the bird flu virus has been found at a farm holding nearly 10 percent of Iowa's egg-laying chickens.

The confirmation of the highly infectious and deadly H5N2 virus means up to 5.3 million hens must be destroyed at the farm in northwest Iowa's Osceola County.

Iowa is home to roughly 59 million hens that lay nearly one in every five eggs consumed in the country.

It's the first chicken farm in Iowa to be affected by the virus, which was confirmed at a turkey farm in the state last week.

Several Midwestern states have been affected by the outbreaks, costing poultry producers nearly 7.8 million birds since March.

The latest farm experienced a high number of chicken deaths and sent samples to labs.

In Wisconsin, Gov. Scott Walker has declared a state of emergency following an outbreak of the deadly bird flu.

Walker on Monday authorized the Wisconsin National Guard to assist authorities responding to the bird flu in Jefferson, Juneau and Barron counties. That includes helping with the response and clean up once the infected birds are killed.

Walker says the state must act "quickly and efficiently to contain the outbreak and protect domestic poultry."

State agriculture officials this month detected the virus for the first time in Wisconsin. It has been found in three flocks affecting tens of thousands of chickens and turkeys.

Authorities stress there was no risk to public health and no danger to the food supply from the highly pathogenic H5N2 strain.