Because the Agriculture Department tests only a small percentage of cows for the deadly disease, Kansas meatpacker Creekstone Farms Premium Beef wants to test all of its cows. The government says it can't.

Larger meat companies worry that if Creekstone is allowed to perform the test and advertise its meat as safe, they could be forced to do the expensive test, too.

The U.S. Court of Appeals for the District of Columbia Circuit on Friday overturned a lower court ruling that would have cleared the way for the testing. The appeals court said restricting the test is within the scope of the government's authority.