The Chicago-based group Mercy for Animals backed up its claims about the conditions at Gemperle Enterprises in Turlock, Calif., with hidden-camera video footage, the Los Angeles Times said.
The Times said Tuesday the video showed chickens being kicked by Gemperle workers and being kept in cramped cages with untreated injuries and among decaying dead birds.
"We believe this abuse is likely rampant across the country," said Nathan Runkle, the group's executive director. "As long as these birds are treated like egg-producing machines, the abuse will likely continue."
Mercy for Animals requested the Merced and Stanislaus County district attorneys to look into possible violations of California animal-cruelty laws.
Gemperle, which supplies eggs to the NuCal Foods distribution network, said the footage showed behavior that did not follow company policy. The Pacific Egg and Poultry Association also condemned the actions.

