CHICAGO -- An activist investor is trying to make McDonald's change the way it buys pork for its bacon cheeseburgers and sausage patties.

       Investor Carl Icahn has nominated two new candidates for McDonald's board of directors, the fast food chain confirmed Sunday.

       The issue Icahn wants to change is that some of McDonald's pork suppliers confine pregnant pigs in small crates. McDonald's vowed a decade ago to phase out using pork from suppliers who use such crates.

       The fast food giant said Sunday it expects to source 85 to 90% of its U.S. pork from pigs not housed in gestation crates during pregnancy by the end of this year.

       Icahn's nominees will stand for election at McDonald's 2022 annual meeting, the company said.

       The move comes as investor-led board shakeups have gathered steam. Last year, several members of Exxon's board of directors were ousted as investors pressured the company to take climate change more seriously.