Title: USDA works on better tests for cattle TB Author(s): Krissa Welshans Source: Feedstuffs. 85.38 (Sept. 16, 2013): p16. From General OneFile. Document Type: Article Copyright : COPYRIGHT 2013 Miller Publishing Company, Inc.
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IMPROVING tests and vaccination methods is one strategy U.S. Department of Agriculture scientists are using to overcome obstacles that prevent the eradication of bovine tuberculosis (TB) in cattle worldwide.

Scientists at the Agricultural Research Service (ARS) National Animal Disease Center in Ames, Iowa, are developing new methods to prevent and control TB in cattle and white-tailed deer.

Veterinary medical officers Ray Waters and Mitch Palmer and microbiologist Tyler Thacker are collaborating with international groups, other U.S. government agencies, the cattle industry and private companies to combat TB. They are developing better tests to help producers identify and remove TB-infected cattle from herds and keep healthy animals.

Widespread pasteurization of milk, development of a diagnostic tuberculin skin test for cattle and establishment of a USDA eradication program have significantly helped decrease the incidence of bovine TB in humans in the U.S.

While the tuberculin skin test for cattle has helped eradication efforts, it does have drawbacks.

"The test is not sensitive enough and requires a 72-hour waiting period for results," Palmer said. "It's very difficult to test a herd of 100 cows and say that this one has TB and this one doesn't because the test may not detect one or two animals that actually have TB."

Interferon-gamma-release assays, another method used to detect TB, are whole-blood tests that require live white blood cells to work. Fresh blood samples must not get too hot and must be processed within 8-30 hours, which requires getting samples to a lab in good condition within a