(CBS/AP) USDA officials have tracked down at least one offspring of California's first case of mad cow and say the cow does not have the disease also known as bovine spongiform encephalopathy (BSE).
The calf was euthanized and brain samples were sent to the national laboratory since there is no live test for BSE. Officials announced Wednesday the test was negative.
The USDA announced April 24 that the nation's fourth case of mad cow disease was discovered in the 10-year-old cow - the first case since 2006,
Two California dairy farms were also quarantined on Wednesday, Reuters reported. The USDA said that was standard procedure while they reviewed records to determine if any at-risk cattle were on the farms.
The USDA has declined to name the dairies or the state where the offspring was found.
USDA officials also said on Wednesday that within the last two years, the diseased cow gave birth to a stillborn calf. They did not say how that carcass was disposed.
Officials also are investigating the calf ranch where the diseased cow was raised before she was sold into dairy productions. Investigators said they have been unable to locate for testing the cattle that were raised with the one who developed mad cow disease.
Mad cow disease is a deadly affliction of the central nervous system that can be transmitted to humans who eat meat from infected cows. The incubation period is two to eight years, and the disease in humans is called variant Creutzfeldt-Jakob disease (vCJD). The disease causes a paid decrease in a person's movement and mental abilities. To date, there have not been confirmed human cases of this type of CJD in the U.S., but a massive outbreak of mad cow disease in the U.K. that peaked in 1993 was blamed for the deaths of 180,000 cattle and more than 150 people,
Cows can contract the disease by eating rendered remains from other sick cattle, which are processed into protein supplements. It's no longer legal to feed cattle to cattle, but rendered cattle are fed to chickens, and chicken droppings and spilled feed are rendered back into cattle feed.
The FDA and the California Department of Food and Agriculture have been examining feed records at the affected dairy and have identified at least 10 suppliers.
The USDA tests 40,000 of the approximately 35 million cattle slaughtered annually for BSE. Baker Commodities is a voluntary participant in the testing program.
The FDA has questions and answers on BSE.