USDA Prohibits Mad-Cow Tests By Outside Labs, Causing Outcry.

Focuses on the testing of cattle for mad-cow disease in the United States. Why the U.S. Department of Agriculture (USDA) does not allow private testing for the disease; Comments from one U.S. resident, expressing anger that only the USDA can test for the disease; View of author that the USDA's qualms about allowing private testing reflects the agency's desire to promote the cattle industry; Comments from David Luker, who owns Missouri Valley Natural Beef, regarding the USDA's policy of being the only certified tester of beef; Indications of public support for expanded options in the testing of cattle.