Trappist monks who operate a chicken farm in South Carolina are disputing accusations from a national animal-welfare group that their birds have been mistreated.

People for the Ethical Treatment of Animals allege the monks at Mepkin Abbey crammed thousands of chickens into small cages and periodically starved them to increase egg production.

"Please shut down this operation forever. It is an ugly stain on your otherwise blessed community," PETA Vice President Bruce Friedrich wrote in a letter posted Wednesday on the group's Web site.

The site displayed a video of the monks' egg farm, taped in January without the monks' knowledge, according to PETA.

The Rev. Stanislaus Gumula, the abbot of Mepkin Abbey, said the group's accusations were "unfactual" and explained that the chickens were caged because it keeps them cleaner and healthier.

"When they are on the floor, they are subjected to all sorts of parasites and bacteria," Gumula told The New York Times. "They walk in their own manure. They walk in their troughs."

The abbey posted a statement on its Web site that said the monks treat their chickens as "one of God's precious creatures" and that its operation was certified last year by the United Egg Producers.

Abbey spokeswoman Mary Jeffcoat said the monks follow the trade group's guidelines.

"They are very hurt by all this," she said.

Mitch Head, a spokesman for the United Egg Producers, the country's largest trade group for commercial egg farmers, said inspectors ensured the birds are handled properly and have the necessary water, food, cage space, air quality and transportation.

On the PETA video, one monk discussed forced molting, a process that involves starving the chickens to make them lay more eggs. The monk compared the practice with a fast.

Molting was banned last year by the United Egg Producers.