YAKIMA, Wash. -- As the United States grapples with developing a national system to track diseased cattle, some here have been watching the Canadian model.

Like Australia, the program requires cattle ranchers to participate and relies on ear tags to register cattle.

But unlike Australia, the Canadian system doesn't actually track a cow's every move from birth to death.

"Whatever we move to, we have to be sure it doesn't impede commerce," said John Masswohl, director of Government & International Relations for the Calgary-based Canadian Cattlemen's Association, which represents about 90,000 beef producers.

"We aren't convinced the technology exists to read every tag every time. ... It's not all 'Star Trek' just yet."

Canada started its mandatory livestock identification program in 2002. The database is owned and controlled by the industry -- the Canadian Cattle Identification Agency -- rather than the government.

Ear tags are registered to the people who buy them. Owners are required by law to tag their cattle the first time they're moved off the farm they're born on. When the animals are slaughtered or exported, that, too, is recorded in the database.

What isn't recorded in the database is every instance of ownership changing hands, Masswohl said.

It's up to producers and owners to keep records of where the cattle went between the birth and slaughter or export. Such records are standard operating procedure for nearly all operations, according to industry officials.

"We have the bookends," Masswohl said. "In an animal health emergency, the tag gives you somewhere to look."

During such emergencies, the government has a right to access the database.

Emergencies are defined as when certain diseases or conditions are reported, such as anthrax, mange, mad cow and bovine tuberculosis. On average, the Canadian Food Inspection Agency carries out about 2,000 trace-backs per year to investigate potential outbreaks of diseases.

Locating the infected animals, though, relies on talking to producers, Masswohl said.

"The perception is the government should go to the computer, press two buttons and have an answer instantly. That doesn't exist in Canada," Masswohl said. "We have to talk to producers and rely on their records, and that's generally been pretty good."