The discovery of mad cow disease in a Holstein dairy cow in Washington state has focused new attention on how cattle are raised and slaughtered.
While the US Agriculture Department rushed to impose a series of new food safety rules, FDA officials have said it would take time before deciding whether extra precautions were necessary to protect US cattle herds from the brain-wasting disease.
Since August 1997, the FDA has banned the use of cattle remains as an ingredient in feed for other cows, goats and sheep - a practice blamed for spreading mad cow disease throughout Britain in the 1980s and 1990s.
"The FDA's animal feed regulations provide the first and best line of defence against BSE," said Representative Lee Terry, a Nebraska Republican.
Officials believe mad cow disease was spread to the Washington cow after it ate the brains, spinal cord and other remains of an infected cow.
Experts say the best way to prevent mad cow disease is to ban this "high risk" material from human food and animal feed.
The USDA last week banned brains and spinal cord from older cattle from the food supply. But the FDA continues to allow these "high risk" materials to be rendered into feed for pigs and chickens.
Some lawmakers and consumer groups are calling for even tougher steps, such as banning the feeding of animal remains to all food animals. Industry officials say these actions are unnecessary as the diseased Washington cow probably became infected in Canada.