Ground beef is displayed for a photograph in the meat department of a supermarket in Princeton, Illinois, U.S., on Thursday, April 26, 2012. The first time mad cow disease appeared in the U.S., beef exports plunged 82 percent. More than eight years later, the discovery of an infected dairy cow in California may do little to prevent shipments from surging to a record for a second straight year. Photographer: Daniel Acker/Bloomberg via Getty Images