Oklahoma City-based Sonic Corp. — which operates 3,500 restaurants in more than 40 states — announced a new food policy, gathering praise from The Humane Society of the United States.

Sonic's new policy will result in the company phasing in the use of cage-free eggs, as well as pork from facilities that do not confine sows in gestation crates. The policy also encourages Sonic's chicken suppliers to switch to controlled-atmosphere killing, a higher-welfare poultry slaughter method than the common practice of shackling and electrified water stunning.

"By starting to use eggs from hens not confined in cruel battery cages and pork from pigs not crammed into tiny gestation crates, Sonic has taken an important first step forward for animal welfare," says Paul Shapiro, senior director of the HSUS' factory farming campaign. "We applaud Sonic for beginning to address animal welfare and look forward to further progress from the company."

Other national restaurant chains, including Burger King, Red Robin, Wendy's, Quiznos, Denny's, Hardee's, and Carl's Jr., have created similar food supplier policies.