Often the forced growth causes such pain in the limbs of the birds that they are unable to move around at all. Often these chickens suffer from Hock Burns and ulcerated feet. When they are gathered for slaughter they are often grabbed by their legs and carried upside down which frequently causes dislocation of joints and other injuries, including bruising and broken wings and legs. The method of slaughter is by stunning and then cutting with a knife. About one third of all broilers are not stunned properly and so are sentient when they go to the knife.
Some birds even enter the scalding tank fully conscious.