Since 2002, PETA has been urging major food retailers to switch from the standard form of poultry slaughter, electric immobilization, to a less cruel method called "controlled-atmosphere killing" (CAK).

Electric-immobilization systems require that birds be handled and processed while they are still alive and conscious, which causes them great suffering. In the slaughterhouses of McDonald's U.S. and Canadian chicken suppliers, birds are dumped out of their transport crates and hung upside down in metal shackles, which can result in broken bones, extreme bruising, and hemorrhaging. Workers have the opportunity to abuse live birds, and birds have their throats cut while they are still conscious. Many birds are immersed in tanks of scalding-hot water while they are still alive and able to feel pain.

Traditional poultry slaughterhouses are dimly lit, stressful, filthy places, which results in poor conditions for workers and an extraordinarily high turnover rate: an annual average between 75 and 100 percent.

Controlled-atmosphere killing could eliminate many of the problems associated with electric immobilization slaughter. With CAK, oxygen is removed from the birds' atmosphere while they are still in their transport crates. The birds are not "gassed" (i.e., asphyxiated); they die from lack of oxygen, or anoxia. During this process, the oxygen from the chickens' environment is removed and slowly replaced with a nonpoisonous gas that puts the birds to sleep while they are still in their transport crates. Approved by the U.S. Department of Agriculture (USDA), CAK is currently used to kill 75 percent of turkeys and 25 percent of chickens in the U.K. and 10 percent of all birds in the European Union.

CAK eliminates the numerous animal welfare, economic, and worker-safety issues associated with electric immobilization. With CAK, birds are dead before they are even removed from their crates—there is no violent flapping of wings or defecation, the air is cleaner to breathe, and there is no opportunity for abuse by workers.

Learn more about CAK and be sure to write to McDonald's and demand that it phase in the exclusive use of chickens killed by CAK by requiring its suppliers to switch to this method.