The Agriculture Department is scaling back its testing program for mad cow disease to about one-tenth of what it has been for the past 2 1/2 years.

Agriculture Secretary Mike Johanns said there is little justification for the current level, which rose to about 1,000 tests a day after the first U.S. case of mad cow disease in 2003.

The new level will be around 110 tests per day for the disease, known medically as bovine spongiform encephalopathy.

"It's time that our surveillance efforts reflect what we now know is a very, very low level of BSE in the United States," Johanns said.

Testing will be scaled back around late August, he said. Johanns said the reduced surveillance remains significantly higher than what is called for by the World Organization for Animal Health.

The United States has had three confirmed cases of mad cow disease: in December 2003, in a Washington state cow imported from Canada; last June, in a Texas-born cow; and in March, in an Alabama cow.

In April, Johanns released a department analysis of testing data, saying the prevalence of mad cow disease "is extraordinarily low." There are probably four to seven undetected cases of the disease in the U.S., according to the analysis.

A panel of independent scientists agreed with the department's analysis, Johanns said.

The brain-wasting disorder infected more than 180,000 cows and was blamed for more than 150 human deaths during a European outbreak that peaked in 1993.

Humans can get a related disease, variant Creutzfeldt-Jakob Disease, by eating meat contaminated with mad cow.