NEW YORK, N.Y. - McDonald's and its supplier Tyson Foods say they've cut ties with a chicken farmer after an advocacy group released a video taken with a hidden camera that the group said showed abusive practices at its farm.

The video was released by Mercy for Animals, an animal rights group that says it has released more than 40 similar videos in the past. The footage shows people scooping chickens into a bucket by whacking them with a pole with a spike on the end, and standing on birds' heads to break their necks.

Tyson Foods Inc. said in a statement that it was investigating the situation, but that it terminated the farmer's contract "based on what we currently know." McDonald's Corp. said in a statement that it supported Tyson's decision to terminate its contract with the farmer in question.

"We're working with Tyson Foods to further investigate this situation and reinforce our expectations around animal health and welfare at the farm level," McDonald's said in a statement.

The farm in Tennessee identified by Mercy for Animals could not immediately be reached.

The farm supplied chicken for McDonald's Chicken McNuggets, according to Mercy for Animals. McDonald's said the farm may have also supplied chicken for menu items including grilled and deep-fried chicken filets and its McChicken sandwich.

Tyson said in its statement that the video doesn't reflect the treatment of chickens by the thousands of farmers that supply it. But Matt Rice, director of investigations for Mercy for Animals, said the group's investigators walk away with images that "shock and horrify" every time they go on site at a farm.

"Unfortunately this type animal abuse runs rampant in the animal agriculture industry," Rice said.

Mercy for Animals is asking McDonald's to adopt a number of animal welfare policies, such as giving chickens more space, ending breeding practices designed to make chickens grow so quickly that they develop health problems, and the installation of video monitoring on farms.

Rice said Mercy for Animals has requested meetings with Tyson, but said the company has declined its requests. A representative for Tyson, Gary Mickelson, said Tyson has previously offered to meet with the group.

News from © The Associated Press, 2015