U.S. dairy farmers’ big bet on global demand for milk is souring.

The industry was in trouble long before a trade squabble with Canada last month that reduced demand for ultrafiltered milk, a cheese ingredient. Dairy farmers fear a spat that has jeopardized roughly $150 million in sales for Wisconsin, New York and Minnesota producers is just a prelude to disruptions to come if President Donald Trump renegotiates the North American Free Trade Agreement as promised.

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