FRESNO, Calif. -- Trader Joe's said Thursday it will stop carrying eggs from a central California farm where an animal rights group shot undercover video showing chickens being mistreated. The Monrovia-based chain saidit wants all its vendors to abide by industry practices for animal care.

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Meanwhile, a farmer accused of animal cruelty on his California egg farm said Tuesday that his chickens are treated well and that gassing a chicken is the most human way to dispose of sick birds.

Ernie Gemperle, who runs a family egg business in Hilmar, spoke out after a video was released by the animal rights group Mercy for Life showing, among other things, gassing of chickens and a worker kicking a bird with his shoe, reported KCRA-TV in Sacramento.

The Chicago-based group conducted a two-month undercover investigation earlier this year at multiple egg farms in Merced County.

"I believe our chickens are treated very well," Gemperle said. "I'm in the business for 57 years. We have improved conditions for birds every year."

Gemperle said his farm is being singled out, and that gassing is the most humane way to dispose of sick birds.

"That's not animal cruelty," Gemperle said. "That's something you have to do when you dispose of chickens."

Mercy for Animals had an investigator pose as a Gemperle employee. The group has not provided proof its video was taken at Gemperle's farm.

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Hens lay 1.5 million eggs a day at Gemperle's farm. It's one of the California's largest egg producers, Gemperle said.