Keel bone damage is a serious welfare concern in laying hens, with mean prevalences of 23% in cages (range: 0-85%) to 63% in single-tier systems (range 33-100%) for birds over 49 weeks of age. Keel bone damage is not only associated with pain and stress, but also reduced egg production and quality. However, studies are limited to commercial layers and the impact of keel bone damage amongst breeder flocks is unknown.

Breeders are of critical importance at the top of the production chain since it is generally known that parental conditions can have long-lasting effects on their offspring's development. Maternal stress in breeders could results in fear development, reduce food competitiveness, and increase severe feather pecking in offspring. The extent to which this applies to younger parent stock and its relevance on a commercial level is unknown, but hugely relevant to production and welfare. This project aims to correlate flock-level prevalence of keel bone damage with flock productivity, mortality, egg quality and chick welfare at different flock ages.