A top food safety official suggested Friday to North Bay ranchers that the "deception" by operators at a Petaluma slaughterhouse will take a long time to unravel and could make it impossible to remove the ranchers' high-end meats from a massive recall.

The investigation of diseased and unsound animals at Rancho Feeding Corporation involves more than cows with eye cancer, as previously reported, the official from the U.S. Department of Agriculture was quoted as saying. He also reportedly said the Rancho recall involves 44,000 establishments around the nation, a figure far higher than can be confirmed from the USDA's website.

Some who attended or were briefed about Friday's meeting said the bar has been set extremely high for those ranchers trying to persuade the USDA that their grass-fed cattle were healthy and that the meat processed from those animals at Rancho remains fit for human consumption. The federal regulators appear so uncertain about all that went on at the slaughterhouse that they may be unable to conclude that the meat was left untainted and not tampered with.

Bill Niman, owner of BN Ranch in Bolinas, said he is seeking relief for at least $300,000 worth of meat in his company's freezers. But after the meeting, he acknowledged that his request "may be trumped by food safety concerns."

The Rancho plant, the North Bay's last slaughterhouse, has been under investigation since early January. Last month the facility shut down after announcing a recall of 8.7 million pounds of meat, a year's worth of production.

The USDA has asserted that Rancho "processed diseased and unsound animals" without a full inspection and that the company engaged in "intermittent circumvention of inspection requirements." The USDA repeatedly has refused to comment on most aspects of the recall or on the various federal investigations, but congressman Jared Huffman, D-San Rafael, has said that the U.S. Attorney's Office is conducting a criminal probe.

While ranchers weren't given many details Friday, they came away with a sense of the gravity of the federal allegations against Rancho in regard to circumventing inspection and safety rules.

"I was amazed at the scope and severity of this investigation and how complex it's going to be," said Sonoma County Farm Bureau Executive Director Tim Tesconi, who attended the meeting.

One unusual aspect of the recall has been its affect on a small group of ranchers who paid Rancho to slaughter their grass-fed beef but who then took control of the meat to sell to high-end restaurants, butcher shops and at farmers markets. Those ranchers were told they also must recall their meat and have it destroyed.

As a result, Huffman and the North Coast's other U.S. Representative, Mike Thompson, urged U.S. Agriculture Secretary Tom Vilsack to send an official to speak to the ranchers. The meeting was held Friday at a USDA office in Petaluma.

Vilsack sent Daniel Engeljohn, an assistant secretary for the Office of Field Operations in the department's Food Safety and Inspection Service. Engeljohn's official web page says he is responsible for ensuring that federal food safety and animal welfare policies are effectively carried out by inspectors and staff in 6,000 meat, poultry and egg processing plants and import facilities around the country.

He spoke to about 10 ranchers from Sonoma, Marin, Napa and San Mateo counties affected by the recall. Staff members attended for the two local congressmen and U.S. Sen. Dianne Feinstein.

Engeljohn reportedly ruled out a quick end to the probes against Rancho.

"This investigation is probably going to continue for many more weeks," said Huffman.

The USDA official spoke of "very deceptive practices" by Rancho, Huffman said. Others privately said Engeljohn spoke repeatedly of Rancho's "deception."

Robert Singleton and Jesse "Babe" Amaral, who were co-owners of Rancho when it closed, did not return calls for comment Friday. There have been no reported cases of illness involving the recalled products.

Sonoma County Supervisor David Rabbitt, who represents Petaluma, said he told Engeljohn and a regional USDA official at the meeting that local ranchers were thrown "under the bus unnecessarily" by being lumped into the recall.

The closed plant on Petaluma Boulevard North was purchased last month by David Evans, owner of Marin Sun Farms. Rabbitt said he asked Friday what the USDA was doing to help Evans reopen the plant.

"They did assure me it was going through the process as quickly as possible," Rabbitt said.

News reports have noted the Rancho investigation involves processed cows that may have had eye cancer. But Engeljohn told the gathering "that's only one issue," Rabbitt said. "It goes beyond that."

Engeljohn also noted that 44,000 establishments had received products that are now tied to the recall. In contrast, the USDA's this week posted online the names of nearly 6,400 establishments in 35 states that received products with meat from the Rancho plant.

However, that list also names 66 regional and national retailers, whose stores could greatly expand that figure.

Thompson, D-St. Helena, said the USDA officials are still looking at whether they can release the ranchers' meat from the recall. He suggested that they will be understandably cautious.

"They shouldn't release anything," he said, "if there's any chance it will cause any problems to consumers."