Assessing the welfare of laying hens housed in conventional, modified and commercially-available furnished colony cages

The welfare of White Leghorn hens housed in conventional battery cages (CON V; 3 hens/cage), modified cages containing a nest box and perch (MOD; 3 hens/cage), and furnished colony cages containing a loose-litter lined dustbath (CWDB; 26 hens/cage) or closed dustbath (CWODB; 26 hens/cage) was assessed. In the first study, behaviour of CONV and MOD hens was observed during the prelaying period. CONV hens exhibited increased frustrated behaviours and fewer comfort behaviours, providing evidence of reduced welfare resulting from an inability to express normal nesting patterns.;Study 2 compared dustbathing behaviour in CWDB and CWODB. Increased bathing frequency, shorter duration to bathe, and longer bouts provided evidence of improved behavioural expression in CWDB. Sham bathing did not satisfy hen behavioural need as apparent from high bout frequencies, short durations, and interruptions to bathing activity. Social competition for the dustbath was problematic.;Bone health of all hens was examined in Study 3. Increased structural bone preservation and improved leg bone strength was afforded by movement and load-bearing activity in MOD, CWDB and CWODB. Improved humeral cortical bone density and breaking strength were only observed for hens with access to raised cage amenities that promoted wing loading. Improvements in bone condition were not the result of reduced egg production or quality.;Study 4 examined hen condition and productivity. Reduced feather condition, increased wound scores, and cannibalism in colony cages indicated reduced welfare due to large group size, however access to the dustbath contributed to improved feather cover. Egg quality was also improved in colony cages. Reduced nesting frustration and opportunity to perch in MOD improved hen feather and foot condition. Maintaining small group size was critical to hen welfare.;Study 5 examined alternative layer housing environments in Europe. Achieving a balance between hen welfare and productivity is possible in aviaries, free run, range and organic production systems, and requires key management strategies.;Collectively, these studies indicate that alternative cage and non-cage housing systems provide welfare benefits to hens that cannot be realized in conventional battery cages. Layer housing environments must continue to evolve with our increased understanding of hen behavioural and physiological needs.