As part of a package of new measures to beef up protections against mad cow disease, the US government announced Tuesday that it will ban all "downer" cattle from entering the human food chain. 

The first mad cow disease infection in the United States was found in a "downer" cow, which was too sick to walk on its own at the slaughterhouse.

Brain and spinal cord tissues were removed from the animal slaughtered on Dec. 9, but its meat was allowed to be processed and sold for human consumption.

Under new regulations becoming effective immediately, all "downer" cattle will be banned from the human food chain, US Agriculture Secretary Ann Veneman told a press conference on Tuesday.

Other new measures unveiled by Veneman include holding meat from cattle that have been inspected for mad cow disease until the test has confirmed negative; barring the use of mechanically separated meat in human food; and prohibiting the use of air injection stunning to kill the cattle to ensure that portions of the brain are not dislocated into the tissues of the carcass.

As an enhancement of current regulations, small intestine of cattle of all ages and skull, brain, eyes and spinal cord of cattle over 30 months old will be seen as specified risk materials and thus are banned from being used in the human food supply, Veneman said.

She also announced that the Department of Agriculture will assemble an international panel of experts to examine its response to the first US case of mad cow disease.

"I am appointing an international panel of scientific experts to provide an objective review of our response actions and identify areas for potential additional enhancements," Veneman said.

US investigators have traced the diseased Holstein dairy cow, living in a farm in the Washington state before being slaughtered, to a herd imported from Alberta, Canada, in 2001.

Ron DeHaven, chief veterinarian at the US Department of Agriculture, on Tuesday said investigators expect to identify within a few days the whereabouts of all 81 cattle imported into the United States at the same time of the Holstein dairy cow. 

(Xinhua News Agency December 31, 2003)