18 months after the discovery of America's only confirmed case of mad cow disease, U.S. officials continue their efforts to recapture lucrative export markets -- particularly in Japan.
Shortly after the discovery, the Agriculture Department strengthened its BSE prevention measures, banning all non-ambulatory or so-called "downer" cattle from entering the food chain. Over the past year, USDA tested more than 375,000 animals for BSE, all of which ultimately have proven to be negative for the disease.
But those efforts may have been dealt a serious setback last week, when USDA announced two internationally accepted tests have produced conflicting results. Now, test results from a lab in England, may soon show whether a U.S. cow DID or DID NOT have BSE.
The USDA's inspector general ordered the tests after a third round of tests on the animal came back positive late last week. An initial so-called "rapid" test seven months ago on 3 animals came back inconclusive. Each was followed up by what is called an IHC test ... and all came back negative for BSE. A third, called the Western Blot, came back just late last Friday: 2 negative and one positive.
Meanwhile, among congressional reaction to the testing order was Iowa Senator Tom Harkin, the Senate Agriculture Committee's top Democrat. He and other lawmakers will ask the USDA to explain why additional tests were ordered after retesting gave negative results. They also want to know why it took months to take additional action.
News of the possible BSE case had a limited impact on the markets.
John Lawrence, Iowa State University Economist: "Here Monday morning before noon we saw the markets drop a dollar and a half or more. I think that is just the emotional, you know, we're uncertain so were going to take a conservative approach and drop the price. I think we'll probably take a wait and see attitude until we get the results back from England.
"I think at that point if it comes back that it is in fact under this second test, positive so we end up with competing tests that may shake the confidence of some people and we may see some market weakness if that is the result."