Since that outbreak, about 25 countries shut off or threatened to close their markets to U.S. beef exports, said Agriculture Secretary Mike Johanns, speaking Monday to the American Farm Bureau Federation's convention, which has drawn 5,000 farmers and ranchers to Salt Lake City.

Had a national animal identification tracking system been in place, supporters say, an investigation to contain the disease could have been completed within 48 hours. Yet efforts to implement such a system bogged down when producers argued over whether registering their livestock should be mandatory or voluntary.

"We needed to move beyond the debate," said Undersecretary Bruce Knight, so a voluntary system was adopted.

Knight predicted that as U.S. restaurants, retail outlets and consumers demand information, more producers will voluntarily register. Still, only 24 percent of the nation's livestock owners have joined the first phase of the program, which lists only a contact person and business address.

In contrast, Utah has moved to the top 10 states in numbers of farmers and ranchers signing on to the infant U.S. system (64 percent). Terry Menlove, director of the state's Animal Industry Division, credits the comparatively high numbers in Utah to a level of trust built between state inspectors and individual ranchers.

"Producers know that a tracking system protects their industry," he said, "and it builds consumer confidence that the food they eat is safe."

Some states, such as Wisconsin, as well as countries such as Canada and Australia, have made livestock registration mandatory. But that has not eased the fears of some ranchers and farmers, and the system probably will remain voluntary.

"I don't trust the government," Michigan farmer William Benson said at the convention. "How do I really know that the information will be kept confidential?"

Others said the need for such a system might be a sign of the times. "Strange things have happened since 9/11. If there's a disease out there, people will expect that it be tracked down immediately," said retired Kansas producer Richard Reinhardt.

Technology that is used to track the spread of animal diseases is similar to devices used at retail stores to prevent theft, said Utah Agriculture Department spokesman Larry Lewis.

Electronic ear tags the size of a quarter that contain 15 numerical digits are attached to livestock. When animals walk past a reader panel, an electronic signal is transmitted to a computer, tracking the number of animals passing by. Tags stay on animals for life.

dawn@sltrib.com