Although the Japanese government is poised to exempt cattle 20 months or younger slaughtered in the United States from screening for mad cow disease, local governments here plan to continue checking all slaughtered cattle.

This "double standard" approach to checking beef for the brain-wasting disease, formally known as bovine spongiform encephalopathy, may confuse Japanese consumers, according to many experts.

"The market will be warped, with imports of unscreened U.S.-produced beef on the one side and domestic beef that has been screened on the other," said Hiroko Mizuhara, secretary general of the Consumers' Union of Japan, which has insisted that the blanket screening process continue.