Christensen Farms, one of the nation's largest pork producers, has suspended seven employees over hidden-camera footage that appears to show sick sows and piglets being abused and neglected at a company farm in Luverne, Minn.

The Los Angeles-based watchdog group Last Chance for Animals on Tuesday released grisly video footage of sick and wounded pigs languishing for weeks in the company's "sick pens"; being dragged by the ears and snouts; and being slapped and stabbed with ink pens to force them to walk. The group is calling on the Rock County Sheriff's Office to bring charges of animal abuse against the facility.

Last Chance for Animals detailed what it said were 18 incidents of animal cruelty and 17 cases of neglect — all misdemeanors under Minnesota law. The Sheriff's Office has not responded to calls for comment.

No commercial animal operation has ever been charged with animal abuse in Minnesota, never mind prosecuted, said Adam Wilson, director of investigations for Last Chance for Animals.

Wilson said leaving a sick pig to waste away for weeks without veterinary care, as one portion of the video appears to show, is no different from abusing a pet dog.

Christensen Farms & Feedlots Inc. responded Friday by suspending the employees and launching an internal investigation into the hog facility. The company, which is based in Sleepy Eye, Minn., is the nation's fourth-largest pork producer, supplying large national chains like Wal-Mart.

"We were disappointed to learn of alleged violations of our animal welfare policies at one of our facilities," Christensen Farms CEO Glenn Stolt said in a statement. "At Christensen Farms, we take the health and welfare of our animals very seriously. It is our responsibility, and we owe it to our packer customers and consumers to provide uncompromising care to our animals. There is no place in this industry for individuals who mistreat animals."

Stolt described portions of the video as disturbing.

Wilson said an investigator for the animal rights group took a job at the Luverne facility in the spring and spent four months shooting footage, some of it in secret, some of it openly.

In his statement, Stolt said the allegations were "disappointing," and the company would re-evaluate its animal welfare and husbandry policies.

The Last Chance for Animals video is the second undercover operation by an animal rights group at Christensen Farms in the past three years. In 2012, Mercy for Animals shot footage of hogs in gestation crates, essentially cages in which sows live. It's a common pig housing system.

The Last Chance for Animals video also highlights the use of gestation crates. Pork producers say the crates keep sows from fighting each other, but some companies in the industry are moving to group sow housing, which allows more room for each pig.

Staff writer Mike Hughlett contributed to this report.

Jennifer Brooks • 612-673-4008