A method and system for receiving, processing, and stunning poultry in a poultry processing facility includes an receiving system for receiving and unloading live poultry from a transport vehicle, a controlled atmosphere stunning system, a stunned poultry hanging station for receiving and transferring stunned poultry to another facility for further processing, such as slaughtering the stunned poultry. Shuttle conveyors and cage pushers coordinate to unload cages of live poultry from the transport vehicle and begin conveying the cages toward the stunning system. Accumulators, cage de-stackers, cage stackers, cage washers, tilted conveyors, and other features may be included with the system.