After additional tests on a cow suspected of having mad cow disease were confirmed positive by the U.S. Department of Agriculture last Friday, ISU experts said the effect on the beef industry has so far been minimal.

The cow was originally tested in Texas last November, where the tests showed conflicting results. In June, the sample was sent to the U.S. Department of Agriculture Lab in Ames for further testing.

The test done in Ames came back negative, but because of the initial positive results additional tests were requested. A Western blot test was ordered and came back positive. The Department then sent the samples to a British lab to do the tests again.

“The next step will be to track the cow throughout her life to find out where her counterparts could be and where she could have gotten the disease,” said Shane Ellis, extension program specialist for the Iowa Beef Center.

“As the secretary of Agriculture said, they will need to examine confirmatory testing to see why they kept getting conflicting results and why it needed to be sent to England.”

Ellis said he does not think consumers will turn away from the beef industry.

“American consumers have shown confidence in the testing process,” he said. “Although we have yet to see for sure how the consumer will react. There might be a drop in demand because of high retail prices in grocery stores.”

Agriculture Secretary Mike Johanns said in a statement that consumers are not at risk because the cow was a “downer,” or unable to walk. Cows unable to walk are banned from the food supply.

“Suspect cattle, such as downers, are pulled and confirmed,” Ellis said. “They do not enter the human food supply.”

A form of mad cow disease has been linked to the consumption of contaminated meat in humans. The disease has killed approximately 150 people worldwide, mostly in Britain, where there was an outbreak in the 1990s.

Johanns said the testing being used may not be the best option.

“Likewise, the protocol we develop as a result of this testing might not be the best option in 2007,” Johanns said.

“Science is ever evolving. It is not static.”

Although the case was confirmed positive, Ellis said the beef market has stayed the same.

“The market has been quite calm and although it could affect the industry, it has remained steady,” Ellis said.

— The Associated Press contributed to this article