Nebraska and federal officials are trying to find out whether bovine tuberculosis has spread from a herd of beef cattle in north-central Nebraska's Rock County.

The herd has been quarantined and officials say the Nebraska Department of Agriculture is working with the U.S. Department of Agriculture also want to find out how the disease was introduced to the herd.

The outbreak is unwelcome to the state's roughly $10 billion cattle industry, which started the year with 6.35 million head.

At stake is the state's tuberculosis-free designation from the USDA. Were that to change, Nebraska producers shipping cattle to other states might have to prove their cattle are disease-free -- an expensive proposition when margins are already tight, said Kelsey.

The cattle would need two visits from a veterinarian, who would test for the TB. "If we lost that tuberculosis-free designation it would put us at a competitive disadvantage" to other states, he said.

The decision on the state's status rests with federal authorities.