MILWAUKEE – Top-selling frozen pizza brand DiGiorno and its cheese supplier cut ties with a Wisconsin dairy farm Tuesday after an animal rights group released undercover video showing workers beating, kicking, stabbing and whipping sick and injured cows.

Wiese Brothers Farm owner Mark Wiese told the Associated Press that he fired two employees and assigned another to duties that don't involve handling animals after seeing the video. Wiese, who owns the 5,000-cow farm in Greenleaf with his brother, said he was unaware of the abuse until late last month.

"My brother and I and our families are just very, very shook up about the whole incident," he said Tuesday. "And we're just going to continue to complete our investigation and make sure changes are made if needed and make our business stronger and better."

The farm sold its milk to Foremost Farms. Foremost supplies cheese to DiGiorno, which is owned by Nestlé USA. Nestlé said in a statement that it had asked Foremost Farms not to send it cheese made from Wiese Brothers Farm milk. Foremost Farms said it had stopped buying from Wiese Brothers on Monday.

An activist with Mercy For Animals shot the video while working on the farm in October and November, said Matt Rice, the group's director of investigations. Clips show cows that can't stand being dragged with ropes and heavy equipment or lifted with clamps. Workers whip, kick and stab other cows to get them moving. One animal bleeds from cuts in its side.