The movement by U.S. food corporations toward more humane treatment of animals experienced a whopper of a shift today when Burger King announced that all of its eggs and pork will come from cage-free chickens and pigs by 2017.

The decision by the world’s second-biggest fast-food restaurant raises the bar for other companies seeking to appeal to the rising consumer demand for more humanely produced fare.

“So many tens of thousands of animals will now be in better living conditions,” said Wayne Pacelle, president of the Humane Society of the United States, which has been pushing Burger King and other corporations to consider animal welfare in purchasing policies. “Numerically this is significant because Burger King is such a big purchaser of these products.”

The decision by Burger King, which uses hundreds of millions of eggs and tens of millions of pounds of pork annually, could represent a game-change in the egg and pork supply business as a huge new market has opened up for humanely raised food animals. Already 9 percent of the company’s eggs and 20 percent of its pork are cage-free.