MINNEAPOLIS — An animal welfare group called on prosecutors Tuesday to file criminal charges against workers and managers at a Minnesota hog farm, saying its undercover investigation documented 36 specific violations of the state’s animal cruelty laws — backed up by graphic video evidence.

Los Angeles-based Last Chance for Animals made the call as it released a five-minute video from footage shot over four months this spring at a Christensen Farms breeding facility in the southwestern Minnesota city of Luverne. Christensen Farms is one of the country’s largest pork producers.

Adam Wilson, the group’s director of investigations, said at a news conference that the video documents a “pattern of systematic neglect and abuse, all overseen by barn managers, and at times witnessed by corporate management.”

Sleepy Eye-based Christensen Farms said it found the video “disturbing.” The company said it has suspended seven employees, launched a full internal investigation and is working closely with local law enforcement.

“There is absolutely no place at Christensen Farms or in this industry for violations of animal welfare,” Christensen Farms CEO Glenn Stolt said in a statement. “As a family farm, the care and treatment of our animals is our highest priority. It is unacceptable that this behavior was allowed to continue, and was not brought to our attention immediately.”