Nearly 1,000 kilometres from Washington, where a team of top Canadian negotiators sit in 11th-hour NAFTA discussions, Peter Strebel works under a cloud of concern at the rural Quebec dairy farm his father founded in 1976. The Quebec milk producer is worried that rumblings that Canada may sacrifice part of the sacred cow of supply management as a concession in trade negotiations with the United States would “punish” the dairy industry, open the floodgates to American milk products and prompt thousands of farm closures north of the border. Nearly 1,000 kilometres from Washington, where a team of top Canadian negotiators sit in 11th-hour NAFTA discussions, Peter Strebel works under a cloud of concern at the rural Quebec dairy farm his father founded in 1976.The Quebec milk producer is worried that rumblings that Canada may sacrifice part of the sacred cow of supply management as a concession in trade negotiations with the United States would “punish” the dairy industry, open the floodgates to American milk products and prompt thousands of farm closures north of the border.Canadian dairy operates under a supply management system, in which farmers are protected from competition because the government blocks out foreign production with high tariffs and sets quotas to limit production and prevent market saturation. With traditional market forces removed, the government decides how much farmers are paid for their production, helping to keep farmers' incomes stable.The protectionist policy, a staple of Canadian agriculture for more than 40 years, has come under periodic attack from U.S. President Donald Trump.