The Bush administration urged a federal appeals court to stop meatpackers from testing all their animals for mad cow disease. The government seeks to reverse a lower court ruling that allowed Kansas-based Creekstone Farms Premium Beef to conduct more comprehensive testing to satisfy demand from overseas customers in Japan and elsewhere. Less than 1% of slaughtered cows are tested for the disease under Agriculture Department guidelines. The agency argues that widespread testing does not guarantee food safety and could result in a false positive that scares consumers.