Burger King's baby steps toward more humane treatment for animals in its supply chain took a whopper of a leap forward today when the fast food chain announced that all of its eggs and pork will soon come from non-caged sources.

According to The Humane Society of the United States, Burger King's new policy will transition to 100 percent cage-free eggs for all U.S. locations within five years, and only purchase pork from suppliers that have documented plans to end their use of gestation crates for breeding pigs.

"Burger King Corp. has demonstrated when it comes to America's largest fast food chains, it continues to set the standard," said Wayne Pacelle, president and CEO of the animal welfare group. "These changes will improve life for countless farm animals and encourage other companies to abide by animal welfare principles up and down their supply chain."

The fast food company has also committed globally, through its Corporate Responsibility statement, to purchase beef from suppliers that source only animals that have been raised in environmentally responsible ways. As a result, none of their beef — or palm oil — comes from known sources involved in the deforestation of tropical rainforests.

In 2007, following discussions with the Humane Society, Burger King became the nation's first major restaurant chain to begin phasing in cage-free products.

Burger King Corp. operates more than 12,500 locations worldwide.