Mad cow disease found in California; USDA says no human threat WASHINGTON (Reuters) - The U.S. Agriculture Department confirmed on Tuesday a California dairy cow had mad cow disease, or bovine spongiform encephalopathy (BSE), the fourth such U.S. case since it was first found here in 2003, but said no parts of the animal entered the nation's food supply. John Clifford, the USDA's chief veterinary officer, said there was "no cause for alarm" from the animal, which was found at a rendering plant that processes diseased or sick animals into non-edible products for use in things like soap or glue. Mad cow, which is believed to cause the deadly brain disease Creutzfeldt-Jakob in humans who eat infected parts from animals with the disease, was first found in the United States in late 2003, causing a nearly $3 billion slump in the nation's beef exports the following year. While there is no evidence that humans can catch it from drinking the milk of an infected cow, fears of a potential backlash among consumers and big importers of U.S. beef caused Chicago live cattle futures drop sharply. The USDA has begun to notify authorities at the World Organization for Animal Health (OIE) as well as U.S. trading partners, but the finding should not affect the nation's beef exports, Clifford said. The USDA is still tracing the exact life of the infected animal, which was found at an undisclosed rendering facility in central California. The carcass of the cow, which the USDA said was infected by an "atypical" form of the disease, would be destroyed. But prices pared some losses after the USDA said it had not entered the food chain. Beef exports plunged nearly 75 percent in 2004 in the wake of the first U.S. incident in late-2003, with USDA reporting net cancellations of beef sales in five out of the first six weeks following the news. Overall beef exports were 321,967 tonnes (292,084 tons) in 2004, down from 1.27 million tonnes in the previous year. Sales would not rebound to more than 1 million tonnes until 2010. The value of U.S. beef exports totaled $809 million in 2004, down from $3.86 billion in 2003, according to the U.S. Meat Federation. JBS USA, a unit of the world's largest beef producer Brazil-based JBS SA, said on Tuesday the company was confident U.S. beef exports, which surged to a record high last year - would not be affected by this latest case of mad cow disease. Reporting by Roberta Rampton in Washington, K.T. Arasu and Sam Nelson in Chicago; Editing by Bob Burgdorfer