Rancho Feeding Corporation, a Petaluma slaughterhouse that is the last place to harvest cattle in the Bay Area, reopened on Monday following recalls of more than 42,000 pounds of beef and a two-week suspension ordered by the United States Department of Agriculture. “We’re back open, and we’ve implemented different procedures to make sure that everything is exactly right,” said Scott Parks, the manager at Rancho. He declined to comment further on Wednesday afternoon, saying he was busy overseeing the resumption of the plant’s operations. Food safety inspectors said cows slaughtered on Jan. 8 were processed without a full examination before slaughter, but exactly what happened that day remains unclear. Many of the plant’s clients speculated that the problem resulted from missing signatures on paperwork rather than any genuine safety problem or health hazard. The recall was the first enforcement action against Rancho since at least 1988, the oldest data available in U.S.D.A.’s online records. The United States Attorney’s Office in San Francisco could not comment while the case is under investigation, referring questions to the U.S.D.A.’s inspection service in Washington, D.C., which also declined to provide an update. What is known is that the slaughterhouse and its clients took an economic hit. After the carcasses were condemned, agents loaded them into a long, open truck and sprayed them with a green dye, said Mike Gale, a co-owner of Chileno Valley Ranch who watched as three of his steers were destroyed. (A sea-green dye, mixed with citronella and detergent, is commonly used to mark meat for final destruction.) “It was pretty pathetic and very upsetting to watch,” he said. “It was probably an inadvertent mistake, but we’re all paying for it.” Mr. Gale waited for Rancho to reopen since it is “very inconvenient to go any place but Petaluma,” but he lost one customer in the meantime. Susan Brady, who raises grass-fed beef at Freestone Ranch in Valley Ford, said the condemnation of her meat took away expected sales and threw off her production schedule. Most of the customers that expected meat this month were willing to wait until March, she said, but she has recently lost sales because she can’t meet demand. Other ranchers who needed to harvest during the closure paid extra transportation costs to take their cows or pigs to the Central Valley or farther. “Any threat to Rancho is a real threat to all of the type of agriculture we have in all of the North Bay,” Mr. Gale said.