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For those who forsook the traditional Christmas turkey or ham for a pot roast or filet mignon, the cooking may have still seemed difficult, but it was nothing compared to the long journey the cow took in order to grace holiday dinner plates.

"It is a long and complex process," said Dan Murphy, vice president of public affairs for the American Meat Institute (search).

Dairy cows, like the one in Washington state that was confirmed Thursday to have contracted mad cow disease, are the usual sources for cuts of beef. Ranchers, dairy breeders or cow operators artificially inseminate cows and use the birth cow for three or four years for its milk production.

After its productivity drops off, the cow is sent to a meat packer, who slaughters the animal and boxes it up to send to a processing company. The processor cuts the beef into steaks or turns it into hot dogs, sausages, ground beef or other forms for sale. The meat is then sold to a wholesaler, supermarket chain or food service chain.

Along the way, the carcass undergoes a series of inspections by government authorities working to prevent diseased or otherwise infected beef from entering the food supply, both for humans and other animals.

Officials say the rigorous inspections have helped prevent the arrival of mad cow disease up to now.

"We have been taking steps since 1990 to protect our beef supplies from this disease. We have a whole series of actions that have been taken to reduce substantially the risk to public health from this disease if it ever were found," Agriculture Secretary Ann Veneman said.

Among the inspections, the Food and Drug Administration (search) regularly surveys animal feed production facilities to make sure that the feed being prepared for farm animals does not include the neural or brain tissue that contains the mad cow disease, scientifically known as bovine spongiform encephalopathy (search). The FDA has banned the inclusion of neural tissue in animal feed since 1997.

Experts say that since the cows killed for human consumption are all under five years old, none could have been exposed to contaminated feed produced in the United States. The cow infected in Washington state was only four years old.

Just to be sure, however, that no beef is infected, the USDA (search) surveillance program condemns and tests any cows displaying signs of neurological problems. For example, because the Holstein (search) slaughtered in Washington was unable to walk, testing was required. As a result, the disease was discovered.

In all, the FDA examines thousands of cattle brains each year in more than 60 diagnostic laboratories around the nation. It also has conducted thousands of inspections of renderers, feed mills, ruminant feeders, dairy farms, protein blenders, feed haulers and distributors.

Despite all the exams, one scientist who has worked with the USDA said he warned Veneman that it was only a matter of time before mad cow was discovered in the United States.

Dr. Stanley Prusiner, a neurologist at the University of California at San Francisco who discovered the proteins that cause mad cow disease, told The New York Times in Thursday's edition, that he advised Veneman to start immediately testing every cow displaying any signs of illness and in time test every cow slaughtered for consumption.

Prusiner said the fast, accurate and inexpensive tests, including one he patented through his university, would only add two or three cents per pound to the cost of beef.

But undertaking such a process is no small task. Already, regulation is quite daunting. The United States has 96.7 million cattle and more than 1 million workers in the beef industry. The average American eats 60 pounds of beef a year.

"We believe the people in North America know that we have the strongest food safety systems in the world. We have the protections in place," Veneman said.

In the meantime, the FDA continues its focus on education, sponsoring workshops for state veterinarians and feed control officials from all 50 states, Puerto Rico, the U.S. Virgin Islands and Canada. Additionally, FDA officials have held briefing sessions with trade associations and consumer groups, and have developed additional guides for complying with regulations.