Animal welfare advocates got major traction this year pushing for cage-free eggs.
In September, McDonald's pledged it would move to 100-percent cage-free eggs in its supply chain. And while the movement was already underway, this announcement seemed to really set off a domino effect.
Some of the biggest egg producers in the U.S., including Rembrandt Foods, pledged allegiance to cage-free. Packaged good behemoths like Nestle and fast food chains like Subway did as well. (See the list of companies below.)
"I can't think of a social issue that food companies rallied around more in 2015 than chicken confinement," says Matthew Prescott, food policy director for the Humane Society of the United States, which has long been egging on producers and buyers to go cage-free.
"I think what happened was that for so many companies, the cage-free issue had been on their docket for 10 to 12 years," says Prescott. But he says until McDonald's announcement, there hadn't been a commitment from a major player.