The U.S. Department of Agriculture (USDA) announced this evening they are sending a brain sample to the BSE World Reference Laboratory in Weybridge, England, from one of the three cows that have tested inconclusive and was later confirmed negative in 2004. A separate test was requested by the USDA's Office of Inspector General on all three samples, and one of the tests returned positive.
"This aged animal never entered the human food or animal feed supply", Jim McAdams, President of the largest organization representing America's cattle industry, the National Cattlemen's Beef Association, said in a press release.
Multiple tests can identify BSE. One commonly used method is the internationally recognized immunohistochemistry (IHC) test. Another test commonly used is the Western Blot test. These two types of tests have returned conflicting results on this sample.
"U.S. beef consumers should know that our beef supply is safe from BSE because we prohibit from the food supply any material that could carry the BSE agent (specified risk materials, or SRMs). USDA also bans from the food supply any cattle that appear to be high-risk, including this animal", McAdams said.