Functional housing systems for high welfare in laying hens: promoting natural behaviors in safe environments

Keel bone fractures (KBF) and injurious feather pecking (IFP) are the major welfare and economic problems in free range laying hens, creating a very poor public perception of egg production and reducing profit for the industry. Studies show that up to 90% of hens suffer KBF in some free range systems (FRS), and most flocks have IFP affecting up to half of hens. Resolving these problems is urgent and timely, since the 2012 EU ban on battery cages increased use of FRS in the UK to over 20 million birds - equating around 14 million hens suffering bone breakage and 5 million suffering IFP each year. Proposed battery cage bans worldwide have raised this as a global issue. Also, a ban on beak trimming, the only effective control for IFP, in many EU countries, with a UK ban proposed, has further increased the urgency of this problem. Industry, legislators and welfare bodies are increasingly recognising many FRS as unsustainable. KBF is mostly due to impacts with housing structures during normal activity, and IFP is thought to originate as misdirected foraging behaviour combined with close hen proximity. There is evidence that greater time spent ranging away from the house reduces both KBF and IFP. This study hypothesises that increased activity away from housing structures and greater range use will reduce KBF by increasing bone strength whilst curbing hazardous collisions, and lessen IFP by promoting natural foraging behaviour discrete from other hens. The study will use a total of 12 free range, 12 enhanced free range and 12 barn systems to monitor flocks AND individual hens for activity in-house and on-range, and range use, by combining newly developed hen-mounted 3d-accelerometers and light-level monitors. We will relate these to keel KBF, IFP, pathogen load, overall health and skeletal function. This will provide evidence to inform production standards to help eradicate the two most serious welfare problems, to the benefit of hens, industry, retailers and consumers.