McDonald’s took another step Friday toward softening its image with animal-conscious consumers, saying it will require suppliers to treat chickens better and slaughter them more humanely.

Birds sold to the chain by poultry giants such as Tyson Foods Inc. and Cargill no longer will be shocked, shackled by the feet to conveyors and have their throats slit, McDonald’s announced. Such methods can leave chickens fully conscious when they are slaughtered.