According to the Humane Society of the United States (HSUS), the Subway restaurant chain – with more than 32,000 locations worldwide and more US restaurants than any other quick-service restaurant chain – will begin phasing in the use of cage-free eggs.

The move coincides with the national launch of the Subway chain's breakfast menu.

Matthew Prescott, corporate outreach director for HSUS's factory farming campaign said: "Subway's new animal welfare policy will help improve conditions for animals within its supply chain and throughout the nation. The Humane Society of the United States applauds Subway for beginning to phase out its use of eggs from hens confined in cages."

As part of its new animal welfare policy, the Subway chain will ensure that, to start, four per cent of the eggs used for its breakfast menu nationwide do not come from hens crammed into battery cages. The brand plans to switch 100 per cent of its eggs to cage-free and has already done so in the United Kingdom.

The Subway brand's new policy also includes giving purchasing preference to pork and poultry suppliers that use more humane methods of housing and slaughter, respectively. Currently, the Subway brand uses a significant amount of pork from suppliers that are phasing out the use of gestation crates to confine breeding pigs, and more than five per cent of its turkey comes from suppliers that use controlled-atmosphere killing, which has been shown to dramatically reduce the suffering of birds during slaughter, says HSUS.

Michele DiNello, director of corporate communication for the Subway brand, said: "We have made a commitment to be more environmentally and socially responsible. We are working with our partners at the Humane Society of the United States and our franchisee-owned Independent Purchasing Cooperative, which sources products and negotiates pricing contracts for Subway franchisees to take the steps needed to do this. There is much work to be done, but we are committed to conducting business in a manner consistent with accepted social practices."

Denny's, Burger King, Wendy's, Quiznos, Sonic, IHOP, Carl's Jr., Hardee's, and Red Robin have created similar animal welfare policies, and the extreme confinement of certain farm animals in cages and crates is outlawed in seven US states, reports HSUS.