Preventing feather pecking in laying hens: from principle to practice

Main aim: The aim of this project is to prevent the development of feather pecking (FP) in laying hens by 1) optimising rearing conditions, 2) developing and validating predictors and indicators of FP and 3) implementing this knowledge in the laying hen production chain. Background: Feather pecking (FP) is a major welfare issue in laying hens. Until now, research has mainly focused on FP in adult hens during the laying period, but recent research suggests that the (early) rearing period plays a key-role in the development of this maladaptive behaviour. It has been suggested that stress in the parent stock as well as suboptimal conditions during brooding and early rearing have a major impact on behavioural development, affecting traits as stress sensitivity and fearfulness through turnover of steroid hormones and neurotransmitter activity. There is evidence that birds that have a low serotonergic neurotransmission and are fearful in behavioural tests at young age are more likely to develop FP as adults. It has also been found that chicks from eggs with a high maternal or exogenous corticosterone content are consistently more fearful in behavioural tests and could therefore be more at risk to develop FP. If valid predictors and indicators of FP would be available and if these measures would be implemented and used by the different parties involved in the laying hen production chain, this would strongly increase our control over FP and increase welfare and production of laying hens in general. Projects: Insight in the role of maternal stress and of the early rearing environment in the development of FP will increase our understanding of FP and is expected to lead to practical recommendations to prevent the development of FP in commercial flocks (Post-doc-project 1). Studying neurotransmitter systems will give further insight in the role of the dopaminergic and serotonergic system in relation to the mental health of the feather peckers (PhD-project 2). Furthermore, maternal hormones, serotonergic neurotransmission, FP and fearfulness will be studied in commercial flocks in co-operation with Ter Heerdt BV, a commercial rearing company (PhD-project 3). These flocks will be followed longitudinally from day 0 through 70 weeks of age and predictors and indicators of FP that can be used in commercial flocks will be developed. Also, an optimal rearing environment that minimizes the risk of FP will be proposed and tested (Post-doc project 1, PhD-projects 2 and 3). This will result in a set of predictors and indicators of FP, as well as recommendations for an optimal rearing environment to prevent FP. This information will be implemented in the laying hen production chain, by setting up a structural and constructive collaboration between the all links in the laying hen production chain (Post-doc project 4).