CHICAGO, June 27 (Xinhua) -- U.S. disputes with its key trade partners have put already troubled diary industry in Wisconsin at even greater risk, local media reported on Wednesday.

According to a Milwaukee Journal Sentinel report, wholesale cheese and butter prices have slumped in recent weeks amid trade spats with Mexico, Canada, China and European Union, who have announced retaliatory tariffs on U.S. exports, including diary products.

"We are looking at a short-term washout of 20 percent of Wisconsin dairy farm milk income on a monthly basis. That's how dangerous this mess is," Pete Hardin, a Wisconsin-based diary industry expert was quoted as saying.

"It's a collapse of confidence in the world market," he added.

About 90 percent of Wisconsin milk is turned into cheese, and all but about 10 percent of that cheese is sold outside the Midwest state, to Mexico and many other countries.

Some dairy companies in Wisconsin said their customers in Mexico told them to put things on hold for a little until they sort out the tariffs ranging from 15 to 23 percent.

Wisconsin reportedly lost 500 dairy farms in 2017, and about 150 have quit milking cows so far this year, putting the total number of milk-cow herds at around 7,600, down 20 percent from five years ago.