The arrival of cooler weather in the Upper Midwest has poultry farmers worrying about the return of bird flu, which last spring wiped out more than 48 million chickens and turkeys nationwide.

The U.S. Department of Agriculture estimates it will have spent $700 million on that outbreak once all the bills are paid.

That doesn't cover farmers' lost sales. It took John Burkel more than three months to repopulate his turkey barns near Badger, Minn., after the flu claimed 14,000 of his birds in a single week. He'll have just two-thirds of his usual supply to sell this Thanksgiving — if flu doesn't strike again.

"I don't know if a guy could do this two times in a row, to be honest," he said.

Sen. Amy Klobuchar, D-Minn., thinks Burkel shouldn't have to. Almost half of all bird flu detections were in Minnesota, the nation's top turkey producer. In 2014, before the flu hit, she got language put into the federal farm bill authorizing a USDA study of how to create insurance for poultry and pig producers along the lines of public programs covering growers of corn, soybeans and other commodities prone to weather disasters. Klobuchar is pushing the agency to complete the study and move quickly to come up with a solution to ensure that farmers like Burkel don't go under.

"This is a way of life for these producers," she said.

One option is to expand the program that already covers cleanup costs after an outbreak.

Setting up a bird flu insurance program is harder than doing so for crops because outbreaks are more difficult to predict, said John Anderson, an economist with the American Farm Bureau Federation. Private insurers say it's almost impossible to write policies covering bird flu losses as long as the risk of another outbreak remains high.