ST. LOUIS — Panera Bread on Thursday became the latest restaurant chain to announce plans to stop using eggs from cage-confined hens.

The suburban St. Louis-based chain said it will use 100 percent cage-free eggs in its U.S. restaurants by 2020. McDonald’s and other chains have made similar announcements in recent months.

Panera CEO and founder Ron Shaich said the company has been working for more than a decade to reduce antibiotic use and confinement across its supply chain.

“While there is more work to be done, we are within reach of a menu without antibiotics and unnecessary confinement,” Shaich said.

Some chains, such as Chipotle, have made animal welfare standards part of their marketing, prompting major chains to begin switching to cage-free eggs. McDonald’s announced in September that it will go to cage-free eggs in the U.S. and Canada over the next decade.

Subway and Starbucks have also said they will make the change, with Starbucks planning to do so by 2020. Subway has not announced a timeline for the transition.

Panera operates nearly 2,000 Panera Bread and St. Louis Bread Co. stores, all in the U.S. except for 12 in Canada. The company said the cage-free commitment applies to shell eggs, hardboiled and liquid egg whites, as well as eggs used in sweet goods, souffles and dressings – all told, about 120 million eggs per year.

Panera said it is currently at about 21 percent cage-free eggs, up from 18 percent last year.