WASHINGTON (September 2, 2009)--An Iowa-based egg hatchery it has launched an investigation following the release of an undercover video displaying some gruesome scenes.

The animal rights group Mercy for Animals shot the video, which shows workers at Hy-Line North America's hatchery in Spencer, discarding unwanted chicks by sending them alive into a grinder, and other chicks falling through a sorting machine to die on the factory floor.

A member of the Chicago-based group who was hired at the plant shot the video over a two-week period.

The narration on the video says the chicks were males, which are considered useless to the chicken industry because they don't lay eggs and don't grow quickly enough to produce meat.

Hy-Line said the video "appears to show an inappropriate action and violation of our animal welfare policies," but it also notes that "instantaneous euthanasia" is standard practice.

Mercy for Animals provided a copy of its tape to The Associated Press.