By CINDY GALLI and RANDY KREIDER
April 12, 2012

An animal rights group today claimed that an undercover investigation has revealed "extreme animal abuse" and unsanitary conditions at a major regional egg supplier -- allegations the supplier firmly denies.

The Humane Society of the United States said in a statement its investigation into the Pennsylvania-based Kreider Farms facilities uncovered "injured and dead hens, including mummified bird carcasses" living inside the same cages as live hens who lay eggs for human consumption as well as chickens who had their heads, legs or wings trapped in cage wires and feeding machinery.

"We found extreme animal cruelty and very serious food safety concerns," said Paul Shapiro, senior director of farm animal protection at HSUS.

Undercover video allegedly shot at Kreider Farms and provided by the Humane Society appears to show birds lying dead among the crowded cages of live chickens.

A previous investigation by ABC News into another egg-producing farm company, Sparboe Farms, revealed such unsanitary conditions that major customers, including McDonald's and Target, dropped Sparboe as their supplier.

The Humane Society said Kreider Farms, headquartered in southeast Pennsylvania, is home to close to seven million egg-laying hens. Investigators said the video shows up to 11 hens packed to a cage, dead birds seemingly left unattended and, of greatest concern to food safety experts, and infestation of flies that can spread salmonella and other diseases through chicken feed.

There are no reports of salmonella outbreaks traced to Kreider, but the presence of so many flies at any egg factory is a warning sign of possibly contaminated feed, according to a former FDA official.

"From the feed [it gets] into the chicken, and from the ovary of the chicken it gets inside the egg and then from the egg into the human and you get salmonella," said David Acheson, former FDA food safety chief and now an industry consultant.

On its website, Kreider Farms says that number of hens is closer to five million and says the farms are dedicated to being "stewards of the land, operating clean, efficient and state-of-the-art facilities and creating a work environment of openness, honesty, trust, and personal satisfaction."

The family-owned company has been the recipient of the Pennsylvania Restaurant Association's Excellence in Food Safety award, according to its website.

Videos available on the website show what appear to be much cleaner conditions for the hens compared to the undercover footage and claim, contrary to the Humane Society report, that the chickens have plenty of room to stretch out in their cages.

Kreider Farms Vice President Tom Beachler told ABC News the Humane Society's allegations are "false and misleading."

"The allegations by [the Humane Society] are a gross distortion of Kreider Farms, our employees and the way we care for our birds," the company's president, Ron Kreider, said in a separate statement. "We are leading the industry by tearing down old, traditional-style egg houses and replacing them with new, state-of-the-art facilities. More than 80 percent of our chickens are housed in larger, modern cages."

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Kreider went on to say the company had no evidence the undercover video footage was taken inside Kreider Farms and said three chicken houses were inspected Wednesday by inspectors "including from the Pennsylvania State Board of Veterinary Medicine." All received a "clean bill of health."

READ: Kreider Farms Full Statement on Humane Society Allegations
Kreider Farms is a major supplier of eggs for the ShopRite grocery store chain in the Northeast. ShopRite said today it has launched its own investigation but has not yet removed any of the eggs from its stores.