FRESNO, Calif. (AP) -- A slaughterhouse at the center of a food safety and cruelty investigation resumed operations Monday after federal officials approved its plan to improve treatment of animals.
However, the investigation was ongoing to determine if animals that might have been sick or lame made their way into the food supply.
The cows were seen on an undercover video shot by an animal welfare group operative working at Central Valley Meat Co. of Hanford.
"We're looking at everything in terms of the investigation and have a team on the ground looking at records and interviewing folks," U.S. Department of Agriculture spokesman Neil Gaffney said when asked about the possibility of a meat recall.
The video showed workers shocking cows on the face. One worker apparently attempted to suffocate a cow by standing on its muzzle.
Some dairy cows were unable to walk or stand, and some had udders so swollen they were unable to keep their legs under them.
The company committed to a number of corrective actions.
"Central Valley Meat will provide better training for our workers, better monitoring of our facilities, and more frequent third-party audits of our operations," the company, owned by Lawrence and Brian Coelho, said in a written statement. "We believe these measures will establish a new industry standard for the handling of animals."
A telephone recording told the company's 450 employees to report for work at 9 a.m. Monday.
The video was shot for Compassion Over Killing, a Washington D.C.-based animal welfare organization.
It shows workers attempting to move to slaughter cows unable to walk on their own. The slaughter of non-ambulatory cows is prohibited by federal rules designed to keep animals that may have mad cow or other diseases out of the food supply.
The group gave the video to officials with the USDA Food Safety Inspection Service on Aug. 17. Two days later, agency officials suspended operations at the plant while it investigated.
"We hope this plant's `action plan' will actually result in improvements related to animal treatment, but we shouldn't forget that many of the so-called `corrective' measures are steps that slaughter plants should already be taking in order to ensure compliance with federal law," said Erica Meier, executive director of the animal welfare group.
The tape prompted McDonald's Corp., In-N-Out Burger and federal nutrition programs to stop buying meat from the plant.
The plant mostly slaughters old dairy cows that have lost their value as milk producers. It will stop taking non-ambulatory cattle at the facility, the USDA said.
Temple Grandin, a noted professor with autism whose life's work understanding livestock was the subject of an Emmy-winning movie, said slaughterhouse officials talked with her about the situation.
Grandin told The Associated Press after watching the video that the dairy industry must share some of the blame for keeping sick cows in production far too long.
"They should send them to slaughter when they are in much better condition," she said. "A few bad dairies milk the cow until she's half dead, and that needs to stop."