The U.S. dairy industry is getting hammered in trade disputes with Mexico, China and Canada, putting Wisconsin farms already in trouble at even greater risk.

Wholesale cheese and butter prices have slumped in recent weeks as buyers and sellers worry about the effect of new tariffs on dairy products, according to Pete Hardin, publisher of The Milkweed, a dairy industry publication based in Brooklyn, Wis.

“It’s a collapse of confidence in the world market. Globally, there’s some spectacular stuff going on,” Hardin said.

About 90 percent of Wisconsin milk is turned into cheese, and all but about 10 percent of that cheese is sold outside the state’s borders.

Mexico buys nearly a quarter of all dairy products exported by the U.S., and the American dairy industry is reeling from $387 million in Mexican tariffs — of between 15 and 25 percent — on cheese.