The demand for broiler meat has been growing for decades, and broiler meat represents the major animal protein source in many countries around the world. To meet the demand for cheap and increasing amounts of broiler meat, a consistent selection for fast growth is employed in the broiler industry. However, this comes at the expense of impaired welfare of the parent stock, i.e. the broiler breeders. Among the significant welfare challenges are the severe feed restriction and the associated welfare problems in terms of physiological stress and development of abnormal behaviour, indicative of frustration and hunger. Furthermore, welfare issues associated with the high level of aggression, particularly sexual aggression, exist, causing increased levels of fear, pain and mortality. Linked to this is the mutilation of broiler breeders, which is used as a preventive measure to reduce damage inflicted to flock mates, but the mutilation is a welfare problem in itself.