1 Introduction One of the major welfare issues in layer chicken production is KBD, which also influences public opinion about commercial large-scale egg production. In commercial laying hens, KBD is regarded as one of the important welfare problems (FAWC 2013; Tainika and Şekeroğlu 2020). Damages to the keel bone are described as a fracture (KF) or deviation depending on the type of damage. Riber et al. (2018) described KF as either sharp bends, shearing and/or fragmented sections of the keel bone.
