A dead cow that tested positive for mad cow disease in California in April had at least one offspring that investigators say they've located. Meanwhile, two dairies are being quarantined as a result of the first outbreak of the deadly illness in more than six years.

Marking the first case of mad cow disease in the U.S. since 2006, California officials announced the discovery earlier this week when a dead dairy cow tested positive for the fatal disease as part of a routine testing protocol.

These animals are called “downer” cows and many health experts insist keeping these cows in the food system heightens the risk of mad cow disease.

As a result, Secretary of the United States Department of Agriculture Tom Vilsack has banned downer cows from our food supply. Vilsack calls the move an advance in food safety and the humane treatment of animals.

During last week’s presidential address President Obama called the current U.S. food inspection system a hazard to public health, citing the recent salmonella-peanut butter outbreak responsible for hundreds of illnesses and nine deaths.

Last year a partial ban on downer cows was put in affect, but surprise-surprise, there was a loophole. If a cow collapsed after passing government food inspection it was allowed into the food supply. This move was initiated after the U.S.’s first case of mad cow disease in 2003.

In 2006 the Bush administration dramatically cut back testing for mad cow disease, despite mad cow outbreaks in Texas in 2005 and Alabama in 2006.

Via the Associated Press.