Government and beef industry officials urged consumers Saturday not to worry about the safety of meat as they await conclusive results of tests to determine whether the United States has a new case of mad cow disease.

State-level agriculture officials, meanwhile, wondered whether the animal detected in preliminary tests was from their areas. Until more exacting tests are done, the Agriculture Department (search) would not identify the animal, the state it came from or the facility in which it was killed. The follow-up process could take four to seven days, the department said Friday in announcing the preliminary test result.

A screening test designed to give rapid results had indicated the animal had mad cow, also known as bovine spongiform encephalopathy (search), or BSE. Such tests cannot confirm whether the animal truly had the brain-wasting disease, so the department labels the results inconclusive.

The more exacting tests were being done at the department's National Veterinary Services Laboratories (search) in Ames, Iowa, which diagnosed in December the nation's only confirmed case of BSE, in a Washington state Holstein.

"The inconclusive result does not mean we have found another case of BSE in this country," Dr. John Clifford, deputy administrator of the department's Animal and Plant Health Inspection Service (search), said when he announced the preliminary finding. "Inconclusive results are a normal part of most screening tests."

The department remains confident in the safety of food in the United States, Clifford said. Meat from the animal did not enter the human food supply or livestock feed, he said. Keeping the carcass out of the supply chain is one of several federal safeguards against introduction of BSE into the food supply. These include rules that bar use of the most potentially at-risk cattle parts, such as brains and spinal cords.

People who eat products containing the protein can contract a rare but fatal disease similar to BSE, variant Creutzfeldt-Jakob disease (search).

The new preliminary results announced Friday was done at an unidentified regional laboratory under an expanded BSE surveillance program. Under the expansion, the department was increasing testing by about tenfold, to more than 200,000 animals, over 12 to 18 months. The regional labs, run by states, began their work June 1, and Clifford said more than 7,000 cattle have been tested under the expanded system.

However, Tom Devine, legal director of the Government Accountability Project, a private watchdog group, maintained Saturday that the USDA surveillance is "systematically flawed" and that the potential new case "is only the tip of the iceberg."

He said the system is "designed to miss many of the mad cow suspects" and that the consensus of the science community is that "the sample is too small even to draw conclusions about trends."

Officials in several states said they had received no word from the government that their states were involved in the new incident.

In Washington state, the deputy director of the state's agriculture department, Bill Brookreson, said Saturday he had heard nothing to indicate his state had a part in the new case. If it were involved, his agency probably would have been notified, "but there are no guarantees," he said.

The department has not notified Florida officials that the animal was from their state, said Liz Compton, a spokeswoman for Florida's agriculture department. Spokespeople for agriculture departments in Ohio, Michigan, Texas, Iowa, Nebraska and Wisconsin also said they had received no word that the animal was from their state and a cattle industry insider in Arizona said he had picked up no buzz that the cow was from there.

Beef industry officials echoed the U.S. Agriculture Department in saying people can continue to eat beef safely.

The infectious agent for BSE is not in beef, and tissues that could contain the agent are not allowed in the food supply, said Janet Riley, a spokeswoman for the American Meat Institute, a trade group. The group's president and chief executive officer, Patrick Boyle, said the preliminary test result shows the government's food supply protections are working. He said he was planning to eat a steak.

The preliminary test results must be considered inconclusive while the more exact testing is under way, said Norman Schwartz, president of Bio-Rad Laboratories in Hercules, Calif., who said Bio-Rad's rapid test found the result that USDA announced Friday.

The screening effectively identifies tissue that could contain the BSE protein while not falsely identifying clean samples as contaminated, Schwartz said. The testing process is new, and errors might creep in if lab officials make mistakes, he said.

"It's just kind of our cautious nature to say we want to see the thing confirmed and make absolutely sure before we raise the red flag," Schwartz said.