With California’s bovine tuberculosis-free status on the line, Tulare County dairy producer Nonning Leyendekker agreed to send his 6,400 head of dairy cattle to slaughter.

The action was necessary because a case of TB has turned up on a nearby dairy. "If we confirm bovine tuberculosis at a second dairy, it will mean an end to California's TB-free status," USDA spokesman Larry Hawkins told the Modesto Bee. That means the state would have to institute a mandatory testing program for all breeding cattle sold that leave the state and all feeder cattle would have to be identified by their location of origin.

So far in the battle against TB inspectors have tested 88 of about 200 herds in Tulare County at a cost of more than $800,000, said Steve Lyle, director of public relations for the state California Department of Food and Agriculture. The state has spent more than $13.6 million in state and federal funds for testing programs and reimbursement to Leyendekker, owner of the Friesian Farm Dairy for the market value of the 6,400 recently destroyed.

Friesian Farm Dairy is where the first case of TB was discovered in May. At that time, about 90 cows from the dairy tested positive and were destroyed. Autopsies to examine the lungs for TB lesions revealed that 27 head did indeed have the disease. However, during routine testing last week, another cow at the Friesian Farm Dairy tested positive for the disease. That combined with a positive test in a neighboring herd could have cost the state its status as TB-free.

If Leyendekker wants to return to dairying he has two options. He can wait six months, or he can go buy new cattle that would have to be tested for TB in a year.

The last outbreak of bovine tuberculosis in California occurred in 1991. The state received its TB-free status in 1999 after a five-year period where no cases of TB were found.

Officials believe Leyendekker's dairy became infected after he bought cattle from Mexico. The purchase of cattle from Mexico is thought to be the cause of a TB-outbreak in Texas, which has led to the loss of that state’s status as TB-free.

Fresno Bee, Modesto Bee, Visalia Times-Delta