The U.S. Department of Agriculture is continuing to investigate Central Valley Meat in Hanford, California after undercover video showed culled dairy cows being abused at the plant, but the agency said late Tuesday that there is no evidence that sick or lame cows were slaughtered for human consumption.

Late last week, animal rights group Compassion Over Killing gave USDA an extended version of a video they say was shot by one of their investigators who worked at the plant. After reviewing the footage, USDA determined that, while there is evidence of “egregious” humane handling violations, there is no evidence that lame animals were entering the food supply.

So-called “downer” cattle, those unable to stand or walk, are not legally allowed to be slaughtered for human consumption, in part because of the risk of Bovine Spongiform Encephalopathy (BSE), commonly known as mad cow disease.

USDA’s Food Safety and Inspection service said it was conducting a “thorough investigation that encompasses food safety and will respond appropriately to its results.”

In April, the USDA confirmed that a downer dairy cow sent to a rendering plant, not a slaughter facility, tested positive for BSE. Downer cattle can be rendered into pet food or poultry feed, but are not allowed to be used in ruminant feed or human food to reduce the risk of BSE transmission.

“Our top priority is to ensure the safety of the food Americans feed their families,” said Al Almanza, Administrator of FSIS. “We have reviewed the video and determined that, while some of the footage provided shows unacceptable treatment of cattle, it does not show anything that would compromise food safety. Therefore, we have not substantiated a food safety violation at this time. We are aggressively continuing to investigate the allegations.”

As recently as 2009, Central Valley Meat was one of the top three suppliers of ground beef to the National School Lunch Program, but USDA did not respond to questions Tuesday about whether Central Valley Meat is still supplying the National School Lunch Program or about how much meat the company may be selling to federal nutrition programs annually.

ABC News reported that the company currently holds a $3.8 million, two-month contract with the government.

Shortly after learning about the video, popular fast food chain In-N-Out Burger announced they had severed ties with Central Valley Meat, which had previously been supplying between 20 and 30 percent of the chain’s beef.

The graphic excerpt of the undercover video posted online, which was reviewed by Food Safety News, shows cows before slaughter covered in dirt and feces, some of them writhing on the ground and bleeding on themselves after being bolted repeatedly, but not rendered senseless. Several cows are shown projectile vomiting, presumably from stress, while being hit repeatedly with the bolt gun.

One cow is shown being suffocated by a worker who stands on the animal’s snout. Some cows seem to survive the bolt gun and get sent down the assembly line still thrashing as they are strung upside down before being bled out. Another clip shows cows being sprayed with hot water and electrically prodded to move them.

Generally speaking, public health veterinarians are charged with observing all animals headed to slaughter — both in motion and at rest — to declare them fit for human consumption. But, as former undersecretary for food safety Richard Raymond explained to Food Safety News, “That does not mean they are out in the pens 24/7.”

While many have questioned whether the FSIS inspectors on site were doing their jobs appropriately, Raymond said it’s likely that the inspectors and the public health veterinarian on hand were doing their jobs, but perhaps were not monitoring the pens where the alleged abuse took place.

Some companies, including Cargill, are now employing around-the-clock video monitoring to ensure that there is no mistreatment of animals, especially after the 2008 scandal involving Hallmark/Westland, which was also a major supplier of the National School Lunch Program. Undercover footage shot by the Humane Society of the United States showed non-ambulatory cows being grossly mistreated, sparking outrage among consumers and animal welfare advocates. The footage prompted the largest ever meat recall in history — 143 million pounds of ground beef — after most of it was eaten.

“It’s unfortunate when something like this happens,” said Raymond, who was undersecretary during the Hallmark/Westland incident. “You would think that this particular segment of the industry would have learned their lesson from Hallmark/Westland, but they apparently haven’t. It’s bad for industry, it’s bad for agriculture, and I don’t feel bad for Central Valley Meat. I didn’t feel bad for Hallmark/Westland. It’s their responsibility to ensure these violations do not happen.”

Like Hallmark/Westland, Central Valley Meat primarily slaughters dairy cows that are no longer productive. According to Raymond, these cows have a tendency to go down because they are 10 to 12 years old, quite old compared to the 30 month old steers raised for beef production.

“They’re not in the best of the health.. and sometimes they have some mastitis,” said Raymond.

Central Valley Meat Co. responded Monday by saying that it was cooperating fully with the USDA investigation.

“At Central Valley Meat Co., ensuring that the livestock we process are treated humanely is critically important,” said Brian Coelho, president of the company, in a statement. “Our company seeks not just to meet federal humane handling regulations, but to exceed them.”

Coelho said he was “extremely disturbed” to be told by USDA of the allegations, but could not comment directly on what was in the video because it had not yet been shared with his company.

James Andrews contributed reporting to this piece.