The U.S. Dept. of Agriculture has posted "An Economic Chronology of Bovine Spongiform Encephalopathy in North America."
The overview states that the first confirmed cases of bovine spongiform encephalopathy (BSE) in Canada and the United States had significant effects on trade and prices of U.S. cattle and beef. However, these incidents occurred during a period of low U.S. beef supplies, near-record beef prices, and strong domestic demand for beef that was largely unshaken by the BSE announcement.