A four-decade tradition of people mud-wrestling pigs at a Wisconsin church's summer fundraiser has been halted after 81,000 people signed an online petition pressed by animal rights activists who raised concerns about animal abuse.

The Original Pig Rassle will be replaced this August after 44 years by a human mud football tournament, St Patrick's Parish in Stephensville, Wisconsin, said in a statement.

It said on its website: "After much prayer and many hours of discussion, we realise that what we had for 44 years in the Original Pig Rassle was memorable, legal and great family fun. We also realise that our parish and diocesan talents could be better spent in areas that are less controversial. It is with great regret that we have discontinued the Original Pig Rassle, we are however, very excited to begin this new tradition at St. Patrick Parish."

"We are simply doing something different this year...we are simply moving in a different direction," Deacon Ken Bilgrien said Wednesday.

Bilgrien declined to discuss the controversy that has engulfed the fundraiser for the church, which is about 35 miles west of Green Bay in central Wisconsin.

In 2014, teams wrestled 37 pigs that were slaughtered afterward, according to the Global Conservation Group, a Wisconsin animal advocacy organisation that launched the online petition.

Some pigs were "punched in the face, kicked, body-slammed, jumped on, yelled at and thrown into a bucket," the group said.

It added: "This illegal animal fighting event is in violation of Wisconsin Chapter 951, titled 'Crimes Against Animals', which outlaws cockfighting, dogfighting, and any other similar fighting between animals or animals and humans."

After hearing about the church's decision, the group posted: "THIS IS HUGE! After 260 days of non-stop campaigning, the church announced today that no further animal abuse events will be held."

Additional reporting by Reuters.