The LayWel project: welfare implications of changes in production systems for laying hens

Abstract

The conditions under which laying hens are kept remain a major animal welfare concern. It is one of the most intensive forms of animal production and the number of animals involved is very high. Widespread public debate has stimulated the call for more animal friendly, alternative systems to barren conventional cages. Directive 1999/74/EC has encouraged technical changes in current systems. Not only have traditional cages been modified (so-called 'enriched cages'), but also new alternative systems (e.g. aviaries) have been developed. There is an ongoing need to evaluate the actual welfare status of hens in these novel systems including those on commercial farms. The LayWel project, was funded via the European Commission's Sixth Framework Programme and national funding from several EU countries. Its general objective was to produce an evaluation of the welfare of laying hens in various systems, with special focus on enriched cages, and to disseminate the information in all member states of the EU and associated countries. The project took into account pathological, zootechnical, physiological and ethological aspects.A major achievement of the LayWel project was the compilation of a database collecting data from different housing systems and thus enabling data comparison. The project partners recommend that support is given to maintaining the database in the future so that data can be more reliably modelled. As the type of data collected did not often allow a formal statistical analysis the evaluation of welfare was a presentation of risk factors and advantages and disadvantages of various housing systems. Conclusions are that, with the exception of conventional cages, all systems have the potential to provide satisfactory welfare for laying hens. However this potential is not always realised in practice. Among the numerous explanations are management, climate, design, different responses by different genotypes and interacting effects. A second major achievement of the project was the development of feather scoring and integument (skin, head and feet) scoring systems together with comprehensive sets of photographs. It is recommended that the integument scoring systems are widely adopted and used in on-going research. Farms should also routinely and frequently carry out integument scoring to assist in the detection of damaging pecking, which is currently a widespread welfare problem. Within LayWel an on-farm auditing procedure was developed in the form of a manual for self-assessment. The manual first explains what is meant by welfare and outlines the relevance of welfare assessment. It also summarises risks to welfare in the main categories of housing system. The second part contains recording forms, with guidance for assessing hen welfare. These enable regular checks of a range of indicators of laying hen welfare to be carried out systematically. The indicators were chosen to be relevant to hen welfare as well as feasible and reliable to apply in practice. A series of conclusions and recommendations were made on v...

Effects of housing conditions during the rearing and laying period on adrenal reactivity, immune response and heterophil to lymphocyte (H/L) ratios in laying hens

“…Currently, the improvement of laying hen welfare is of great concern to the European Commission and EU egg industry (Council Directive, 1999; EFSA, 2005;Blokhuis et al, 2007). In recent times, there have been concerted research efforts focusing on modifying cage designs and improving hen welfare (Appleby et al, 2002;Blokhuis et al, 2007).…”

“…In recent times, there have been concerted research efforts focusing on modifying cage designs and improving hen welfare (Appleby et al, 2002;Blokhuis et al, 2007). A furnished cage system (FC) attempts to provide an enriched environment to meet the behavioural needs of hens while maintaining a small group size to minimize stress (Tauson, 1998).…”

“…-E-mail: randi.moe@nvh.no 1709 However, discrepancies in the outcome assessment regarding mortality, plumage conditions and production parameters have been reported for new housing systems (EFSA, 2005;Blokhuis et al, 2007), although several factors could have been responsible for the inconsistent results, including differences in cage designs, group sizes, stocking densities, application of beak trimming and the genotype of birds used (EFSA, 2005).…”

“…A furnished cage system (FC) attempts to provide an enriched environment to meet the behavioural needs of hens while maintaining a small group size to minimize stress (Tauson, 1998). In contrast to the conventional cages (CC), FC are equipped with nesting areas, perches and litter areas to increase opportunities for the hens to exhibit natural behaviours and thereby improve their welfare (Appleby et al, 2002).-E-mail: randi.moe@nvh.no 1709 However, discrepancies in the outcome assessment regarding mortality, plumage conditions and production parameters have been reported for new housing systems (EFSA, 2005;Blokhuis et al, 2007), although several factors could have been responsible for the inconsistent results, including differences in cage designs, group sizes, stocking densities, application of beak trimming and the genotype of birds used (EFSA, 2005).Access to litter at an early age stimulates ground pecking and dustbathing, and influences the propensity for injurious feather pecking in laying hens during the laying period (van de Weerd and Elson, 2006). Therefore, the early rearing environment has been presented as one of the most important factors affecting the ability of hens to adapt to the housing environment during the laying period.…”

“…FC or CC) during the laying period (Hetland et al, 2004). Hens for this study had been recruited from that large-scale experiment in order to explore measures relevant to stress and adaptation that have been presented as an important approach for addressing hen welfare (Blokhuis et al, 2007).The activation of the hypothalamo-pituitary-adrenal (HPA) pathways by environmental stressors plays an important role in the coordination of the physiological response to stress, including the immune response in laying hens (Siegel, 1985;Dohms and Metz, 1991). Therefore, physiological, haematological and immunological variables relevant to long-term stress may be recorded in order to understand how early rearing management practices including housing conditions influence the adaptation process of laying hens.…”