Pork, the fastest-growing United States meat export of the past decade, is sick with swine flu in what is turning into a crisis for American farmers.

US exports of the meat plunged 20% in the first half of the year and are heading for the first annual decline since 1990 after the H1N1 virus outbreak in April led to import restrictions in China and Russia.

Some slaughterhouses have been left idle and US hog farmers haven't been profitable in a year.

Swine flu will contribute to an 11% drop in global pork trade this year, even after scientists said the meat is safe to eat, United Nations data show.

Slumping exports, the global recession and improvements in breeding methods have left stock levels high.

“What do we do with all these hogs?” said David Kruse, a commodity trading adviser at CommStock Investments in Iowa. “The industry is just not structured to modify production in response to reduced demand. The industry is basically structured to go broke. It will produce hogs until it runs out of money.”

Hog futures are already the second-worst commodity investment of the year and are tipped to fall further. US farmers are losing $30 to $35 on every pig they sell this month and may not make money until May, dealers say. Producers have been unprofitable for 20 of the 22 months to July, and more than 5000 of them may have to exit the business, he said.