The bovine TB investigation has confirmed only two cases of the disease in one Rock County herd, but state Agriculture Director Greg Ibach said the other 31 herds have been quarantined because the animals may have had fence-line contact with the infected herd.
The 32 quarantined herds, which must all be tested for TB, are in Rock, Holt, Loup, Boyd and Brown counties. Ibach said other herds could be added to the quarantine if investigators learn they may have contacted the infected herd.
Testing of all the quarantined herds will begin next week, but that will take a considerable amount of time to complete.
"This is a process that will take months, not weeks to complete," Ibach said.
While the quarantine orders remain in place, none of the herds included will be able to sell cattle unless they obtain a special permit for immediate slaughter, Ibach said.
About 500 cattle producers traveled to Bassett Thursday for a meeting about bovine tuberculosis with Ibach and the state veterinarian.
State officials are working with the U.S. Department of Agriculture to investigate the TB cases and determine whether Nebraska can keep the tuberculosis-free label its held for the past 17 years. Losing the state's tuberculosis-free designation would put Nebraska's roughly $10 billion cattle industry at a competitive disadvantage, industry experts say.
Ibach said the owner of the herd where two animals tested positive has not decided what will happen to his herd, which has been quarantined since last week.
Bovine TB is considered untreatable, so both infected and noninfected cattle in a herd usually are killed.
The other option is continued quarantine and testing. But an entire herd must have eight consecutive clean tests before the quarantine could be lifted, a process that could take years.
Ibach said officials have not yet determined whether the sick animals came from Nebraska or another state.
Experts say tuberculosis is a contagious disease of animals and humans, caused by three types of bacteria.
Bovine TB can be transmitted from livestock to humans, but that's exceedingly rare. It can be transmitted to other animals.
"The chances of a human being contracting this disease is virtually zero," Ibach said.
The disease is easily transmitted through a herd of cattle through nose-to-nose contact. It causes severe coughing, fatigue, emaciation and debilitation.
The U.S. Department of Agriculture says Nebraska started the year with 6.35 million head of cattle and calves.