The annex to the proclamation signed by President Donald Trump on 8 September lists 14 provisions of the US tariff schedule: eight subheadings of 0404.10 — whey protein concentrate, fluid whey, dried whey and modified whey — five molasses lines and non-alcoholic beer. Cheese, yoghurt, butter, fluid milk, milk powder and ice cream do not appear on it.
Canada sold $35.04mn of whey under the line into the United States last year, or 21,000 tonnes, 47.6 per cent of a $73.6mn import market and the largest share, according to US Census Bureau trade data accessed via Cropli.
Whey protein concentrate is an input for food manufacturing and sports nutrition rather than a retail product. The banned line is about an eighth of the $262.2mn of Canadian dairy the United States imported under tariff headings 0401 to 0406 last year. Yoghurt and fermented dairy, the second-largest of those lines at $76.27mn, is also absent from the annex.
OTTAWA'S RESPONSE 15 TIMES LARGER
Canada's retaliation is roughly 15 times the size of what was banned. Counter-tariffs of 15, 25 and 50 per cent on C$27.6bn ($20bn) of US goods took effect at 12:01 a.m. on 8 September, hours before the proclamation was signed, matching "dollar for dollar" the 50 per cent duties Washington imposed on 22 August.
Dairy accounts for $524mn of the 2025 Canadian imports from the United States on the list, including $132mn of cheese, according to the US Department of Agriculture's post in Ottawa.
Heading 0404 is on Canada's list at 50 per cent, so whey is hit in both directions. US exporters sold Canada $99.26mn of whey and milk products last year, their third-largest market for the line after China and Mexico.
Absent from Finance Canada's schedule of 648 counter-tariffed lines are butter and milk fats and fluid milk and cream, the two dairy headings where Canada is the United States' largest customer.
US exporters sold Canada $228.35mn of butter and milk fats last year, 38.3 per cent of all US shipments of the line, and $69.68mn of milk and cream, 40.8 per cent of the US total.
The Ottawa post's figures point to why: Canada is short of butterfat. Butter stocks reached "nearly 26,000 MT in July 2025, compared to 28,000 MT 12 months earlier, remaining well below the industry's target volume of 35,000 MT", it wrote in its annual dairy report last November.
The US share of Canadian butter imports over January to August rose to 69.5 per cent last year from 55.9 per cent in 2023, on Trade Data Monitor figures. A second carve-out shelters the same trade: dairy brought in under Canada's re-export programmes is exempt, and about two-thirds of Canadian butter imports are destined for processing into food that is then exported.
US fish and seafood, worth $774mn of 2025 Canadian imports, was on the original schedule and removed a day after publication, with the federal government citing feedback and a wish "to protect against broader economic harms", the Ottawa post wrote.
"In the case of dairy products subject to tariff rate quotas (TRQs), the Canadian counter-tariffs apply to both over-quota and in-quota imports," the post wrote, meaning the access Canada guaranteed American exporters under the US-Mexico-Canada Agreement is taxed along with the rest.
CHEESE DISPUTE, WHEY REMEDY
The proclamation invokes section 338 of the Tariff Act of 1930 against Canada's "tariff-rate quota allocation measures imposed on U.S. cheeses of all types", finding that on 21 August "Canada reneged on its commitment, ceased negotiating in good faith". The remedy is a ban on whey.
Cheese was handled separately the same day in a companion proclamation that added various cheese products to the 50 per cent duty list without banning them, Agri-Pulse and Dairy Herd reported. MS NOW described the proclamation as banning "all Canadian dairy products".
US dairy groups are not united behind the campaign. Krysta Harden, chief executive of the US Dairy Export Council, said in a statement issued before Ottawa announced its counter-tariffs that the new round of tariffs "makes clear that patience has run out".
Others expect the cost to fall at home.
"Any time that you get a market disruption, it usually lowers the price to the farmer, but also gives the middleman, the multinational corporations, the ability to raise the price on consumers," Darin Von Ruden, president of the Wisconsin Farmers Union, told MS NOW.
"What we are worried about is an escalatory spiral," Michael Harvey, executive director of the Canadian Agri-Food Trade Alliance and a member of Prime Minister Mark Carney's advisory committee on bilateral US economic relations, said in remarks reported by Dairy Herd. "But at the same time, we totally understand that the prime minister needs to find areas of leverage."
There is no sign yet of the trade thinning ahead of the deadline. Canada shipped 11,910 tonnes of the line to the United States in the seven months to July, against 11,840 tonnes a year earlier, with higher unit prices lifting the value 28 per cent to $25.53mn. The 50 per cent duty took effect only on 22 August, after the period those figures cover.
Denmark, the alternative at scale, sold $21.28mn into the market last year, 28.9 per cent of it, while the Netherlands, France and Argentina sold about $14mn between them.
Goods imported but not entered for consumption before 12:01 a.m. eastern time on 29 September will stay on the 50 per cent rate rather than being turned away.
US Trade Representative Jamieson Greer and Dominic LeBlanc, Canada's minister responsible for trade with the United States, spoke in the days before the proclamation and were expected to speak again to see whether there was an alternative path, a US official told Dairy Herd.
