The issue dates back to 2012 when McDonald’s announced that it would require its U.S. pork suppliers to outline their plans to phase out the use of so-called sow gestation stalls, which are too small in length and width for pigs to move about or even lie down. The decision at the time was supported by the Humane Society of the United States.

McDonald’s disputes Icahn’s assertions and says it’s been a leader in moving the industry away from the practice. By the end of this year, it said Sunday, the chain expects to source 85% to 90% of its pork volume from sows that weren’t kept in crates during pregnancy — and by 2024 to have all its supplies from sows that were kept in groups.

The chain also called out Icahn for not adopting similar commitments on behalf of Viskase Cos Inc., a pork-and-poultry packaging company in which he’s a majority owner. Icahn has called for additional steps, such as requiring all of McDonald’s pork suppliers to go to crate-free pork, which currently would be “impossible,” the restaurant company said.

In an interview with Bloomberg Television last week, Icahn said the issue isn’t a financial consideration for him, since he only owns about 100 shares of the chain. The real issue for him is “emotional” and the “unnecessary suffering” experienced by the animals.

“I think there’s a way I can be really helpful,” Icahn said in the interview. “That’s a situation that is just horrible. It’s obscene. You got these companies making all this money and the animals are just suffering for no reason.”