The U.S. cattle herd is free of the so-called "mad-cow" disease that has panicked Europeans and sent meat sales plunging in some European nations, according to the National Cattlemen's Beef Association (NCBA). The cattle and beef trade organization credits U.S. prevention of the disease, bovine spongiform encephalopathy (BSE), to "more than 10 years of aggressive, coordinated government and industry efforts."