Nearly a week after the USDA announced it would be doing additional tests on a previous bovine spongiform encephalopathy suspect cow, a Weybridge, England BSE lab received a hand-delivered tissue sample.
According to Reuters, only 12.5 grams of the area of the cow's brain needed for testing still remains. It took USDA six days to determine testing methods to clear up confusion regarding whether the animal is infected. A statement from Secretary of Agriculture Mike Johanns explains that USDA has agreed upon a protocol that includes additional testing both at USDA and at an international reference laboratory in Weybridge, England.
Here's an overview of the testing:
- The Weybridge lab will do an immunohistochemistry test, the same one that was done initially in November 2004 that came up negative. The IHC test has been called the "gold standard" of BSE tests.
- The international lab will also carry out three kinds of Western blot tests, the same type of test that was run the week of June 5 revealing a "weak positive." The three Western blot tests include one prescribed by the World Organization for Animal Health, a NaTTA version and one designed by Prionics--the makers of the test.
- In addition, the USDA animal lab in Ames, Iowa will conduct another IHC test plus the Western blot test prescribed by the World Organization for Animal Health.
- The USDA will also conduct a BioRad rapid screening test, which was the first to come up as "inconclusive" in November 2004, and an IDEXX rapid screening test.
- USDA will sequence the DNA from the animal's prion protein.
The thorough testing will assist USDA in determining if this is an atypical case of BSE, classical BSE or a non-infectious abnormal condition. USDA is unwilling to pinpoint a timeframe of when results will be made because of the extensive testing planned. Western blot tests take one to two days to receive results and IHC tests take between four and seven days.
Cattle groups blame USDA for market disruption
R-CALF USA released a statement criticizing USDA's handling of the results from retesting the tissue.
"U.S. cattle producers thought this issue was settled more than seven months ago because USDA told the public the BSE tests it used were the â€˜gold standard,â€™" says Leo McDonnell, R-CALF USA president and co-founder. "USDA is now parading the most recent test results as a â€˜weak positive,â€™ without providing any information to the industry as to whether â€˜weak positiveâ€™ truly means BSE was found in the sample, or whether that term simply means the sample was abnormal in some other way."
In November 2004, USDA announced test results from this animal as â€˜inconclusive,â€™ which immediately caused a $70/head drop in cattle prices â€“ a direct hit that lasted about three weeks â€“ with a negative impact to the industry of approximately $126 million.
"Once again, USDAâ€™s actions surrounding this same animal have unnecessarily caused extreme volatility in the marketplace, and conditions can only be described as miserable," McDonnell adds. "Markets are reeling as a result of USDAâ€™s indecisiveness, which is causing irreparable harm to our industry, and someone needs to take the reins and steer us back on a proper course."