MINNEAPOLIS (AP) — In a story April 19 about a U.S.-Canada trade dispute, The Associated Press reported erroneously that Canada had recently imposed duties on 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:

19 Minnesota dairy farms affected by US-Canada trade dispute

A U.S.-Canada trade dispute has spread to Minnesota, where officials say 19 dairy farms are affected

MINNEAPOLIS (AP) — A U.S.-Canada trade dispute has spread to Minnesota, where officials say 19 dairy farms are affected.

Lucas Sjostrom, (SHOW'-strum), executive director of the Minnesota Milk Producers Association, said Wednesday that 19 Minnesota producers are among the 70 to 75 initially reported as all being from Wisconsin.

Canada recently 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.

The affected farms supplied Grassland Dairy Products of Greenwood, Wisconsin, which lost its market for the product. Many of those farms may now be forced out of business.

Minnesota Gov. Mark Dayton wrote to President Donald Trump last week urging him to uphold free trade.

Trump said in Wisconsin Tuesday that he'll work on a solution.

Some New York producers are also affected.