The Supreme Court will decide whether the state of California can block the slaughter of sick pigs.
The high court on Monday agreed to hear an appeal from the National Meat Association.
California strengthened regulations against slaughtering so-called "downer" animals after the 2008 release of an undercover Humane Society video showing workers abusing cows at a Southern California slaughterhouse. Under California law, the ban on buying, selling and slaughter of "downer" cattle also extends to pigs, sheep and goats.
That law was blocked by a federal judge at the urging of pork processors. But the 9th U.S. Circuit Court of Appeals said the state law could be enforced.
Meat processors want the Supreme Court to overturn that decision.
The case is National Meat Association v. Brown, 10-224.