Thousands of TB cows to be slaughtered

More than 4800 dairy cows at risk of carrying tuberculosis are being slaughtered this week in central California, where nearly 16000 cattle in the country's largest milk-producing region have been quarantined.

US government agriculture official Bruce Knight met privately with local dairy operators on Tuesday, along with the state veterinarian and other industry officials monitoring three new cases of TB recently discovered in Fresno County dairies.

Federal and state agriculture officials were still tightlipped about the identities and locations of the three dairies where cows tested positive for the disease, which can be transmitted to humans and other mammals through the air or through drinking unpasteurised milk from an infected cow.