The nesting behaviour of laying hens in large furnished cages

Conventional cage housing systems are criticized for limiting the space and opportunityfor laying hens to perform highly motivated behaviour patterns, especially nesting. Incontrast, furnished cages positively impact the welfare of hens by providing necessaryresources, like nest areas. However, the current requirements for a nest, stipulated withincurrent guidelines and welfare schemes, are ambiguous and often based on the assumptionthat frequent nest use equals satisfied nesting motivation. Because furnished cages are stillrelatively new, my initial research question dealt with how hens used the nests provided.I characterized the nesting behaviour of hens with different space allowances, in differentcage sizes, and from different rearing environments. The design of the cage, compoundedby the effect of cage size, significantly influenced nesting behaviour. Also, the use of thenest did not necessarily indicate good welfare. This led to my second research question:what types of environments impact and/or satisfy nesting motivation? Through threeiterative experiments, I explored different aspects of cage design and investigated howthey influenced nesting behaviour. Simple alterations such as adding a wire partitionto another area of the cage created an alternate nest and affected both egg location andnesting behaviour, although not ubiquitously. Hens without any experience of enclosednests were more aggressive and unsettled in their pre-laying behaviour, and seemed toprefer laying on a different surface than those hens given two enclosed nests. When anenclosed nest was added, hens without prior experience seemed to become more settled.The ultimate goal of this research is to make suggestions that will improve the design offurnished cages so that they truly do satisfy nesting motivation.