A shareholder in McDonald's in the US has called on the company to ensure that all its US suppliers move to crate-free pork production.

Billionaire, Carl Icahn, has claimed that the fast-food giant - in which he owns 200 shares - currently deals with suppliers that house pregnant sows in small crates. He has called on the company to set specific timeframes for producers to move away from this farming practice.

In his bid to succeed in changing the way that McDonalds acquires its pork, the businessman - known for buying stakes in large companies and pushing for change that will increase the company's stock values - has nominated two new board appointments.

These individuals will stand for election at the company's 2022 annual meeting.

A statement from McDonald' s said that Icahn's "stated focus in making this nomination relates to a narrow issue regarding the company's pork commitment".

In 2012, McDonald's said it became the first major brand to make a commitment to source from producers who do not use gestational crates for pregnant sows.

Since making that commitment, "it has led the industry" and today, "an estimated 30–35% of US pork production has moved to group housing systems", the company said.

By the end of 2022, the company expects to source 85-90% of its US pork volumes from sows not housed in gestation crates during pregnancy.

It is envisaged that 100% of this pork will come from sows housed in groups during pregnancy by the end of 2024.

The company attributed "industry-wide challenges for farmer and producers, such as the Covid-19 pandemic and global swine disease outbreaks" for the delay in achieving this.

The statement continued:

"Mr. Icahn, who states that he holds 200 shares of McDonald's stock, is the majority owner of Viskase, a company that produces and supplies packaging for the pork and poultry industry.

"Mr. Icahn's ownership provides him with unique exposure to the industry-wide challenges and opportunities in migrating away from gestation crates."

The company said it was noteworthy that Icahn has not publicly called on Viskase to adopt commitments similar to those made by McDonald's in 2012.

McDonalds has said that a commitment to source all its pork from crate-free production would be "impossible" due to the volumes of pork supplied in the US.

It added that such a move would reflect a "departure from the veterinary science used for large-scale production throughout the industry, and would harm the company's shared pursuit of providing customers with high quality products at accessible prices".