States have begun legislating against cage egg production and dozens of major U.S. food retailers, restaurant chains, and foodservice providers—as well as hundreds of U.S. universities—are switching to cage-free eggs. Extensive scientific evidence strongly suggests this trend will improve food safety. All sixteen scientific studies published in the last five years comparing Salmonella contamination between caged and cage-free operations found that those confining hens in cages had higher rates of Salmonella, the leading cause of food poisoning related death in the United States. This has led prominent consumer advocacy organizations, such as the Center for Food Safety, to oppose the use of cages to confine egg-laying hens.
The Humane Society of the United States, "An HSUS Report: Food Safety and Cage Egg Production" (2011). IIA. 17.