MADISON, Wis. (AP) — In a story April 7 about a trade dispute between the U.S. and Canada over milk, The Associated Press reported erroneously that Canada had decided to impose duties on imports of a product called ultra-filtered milk. Canada changed its policy on pricing domestic milk to cover more dairy ingredients, leading to lower prices for Canadian products including ultra-filtered milk that compete with the U.S. product.

A corrected version of the story is below:

Wisconsin, New York officials step into milk trade dispute

Wisconsin and New York state officials have asked the U.S. Department of Agriculture to take action to help dairy farmers in their states who've been hurt by Canada's decision to change policy in pricing its own milk

MADISON, Wis. (AP) — Wisconsin and New York state officials have asked the U.S. Department of Agriculture to take action to help dairy farmers in their states who've been hurt by Canada's decision to change policy in pricing its own milk.

The U.S. farmers produce ultra-filtered milk, which is used in cheese-making. Canada's policy change has led to lower prices for Canadian products including ultra-filtered milk that compete with the U.S. product.

Wisconsin agriculture Secretary Ben Brancel and New York agriculture Commissioner Richard Ball wrote to USDA Acting Deputy Secretary Michael Young on Friday. They're asking the USDA to create a market by buying surplus cheese and butter, and distributing them through the school lunch and other food aid programs.

About 75 Wisconsin dairy farmers have watched their market dry up. The letter didn't say how many New York producers are affected.