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

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There are 36 million UK laying hens producing 10 billion eggs with a retail value of £1 billion. In the EU 335 million hens generate E10 billion, and globally there are nearly 5 billion hens producing over 1 trillion eggs. Egg production is a major wealth creator and a key element of global food production. In the EU, battery cage systems have been banned, with much of the production switched to free range systems (FRS). Similar legislation is proposed in many other countries, including India and the USA. FRS provide many health and welfare benefits to laying hens, however two major threats to welfare and production have recently emerged which require urgent action. Keel bone fractures effect on average 60% of hens in FRS, with some systems as high as 90%. These are painful and reduce productivity and profit. With up to 20 million UK hens suffering from keel fractures each year, the Farm Animal Welfare Committee regard this as the most serious problem of hen welfare. Injurious feather pecking (IFP) affects as many as half the hens in over three quarters of all FRS, resulting in pain, decreased egg production, increased feed consumption, and often leading to cannibalism and death. Beak trimming, the main means of controlling IFP, is now banned in a number of EU countries, with a UK ban proposed for 2016, leaving producers with no effective means of control. Urgent action is therefore needed to devise an alternative strategy to reduce levels of IFP. Welfare in laying hens remains a serious public concern, with over 75% of UK and EU citizens regarding hen welfare as inadequate.We have shown that impacts with structures within housing systems during normal activities are the major cause of keel fractures. However, hazardous housing structures cannot be entirely eliminated, and reducing activity, as seen in battery hens, seriously impairs skeletal function. We have shown that FRS hens making greater use of the range are more likely to remain fracture-free. However, range use in many systems remains very low, and the potential benefits of ranging are not being realised. We hypothesise that increased range use will promote activity away from hazardous structures, improving bone strength and skeletal function, but avoiding injurious impacts which generate keel damage. Similarly, we and others have indicated that ranging significantly reduces IFP, with an 89% drop in systems with substantial range use. Thus we hypothesise that action to increase range use will reduce incidence and severity of IFP, and encourage natural foraging behaviours.The aim is to determine whether actions to increase activity and natural behaviours in a safe environment will substantially and significantly reduce keel fractures and IFP in laying hens. However, ranging and activity may have other health and production consequences, and these will be examined at flock and individual level, allowing us to determine the effects of range use on the overall wellbeing of hens and the economic impact for the producers.This study will combine video monitoring, welfare assessments, cutting-edge activity logging developed in previous BBSRC funded research, and light-level monitoring technology provided by Biotrack, a leading animal monitoring specialist. We will compare normal FRS, enhanced FRS and barn systems to get a breadth of individual and flock activity, ranging and behaviours. For the first time, this will allow evaluation of range use and activity in flocks and individual hens in commercial production units, provided by Stonegate, our Industrial Partner, one of the UK's leading egg producers. By examining welfare outcomes of feather pecking behaviour, plumage scores and keel fractures, we can assess relationships with fracture incidence and IFP levels. We will further determine how activity relates to biomechanical, metabolic, physiological and radiological changes in bone, to better understand how exercise influences skeletal function in chickens.