Can minor, easily applied alterations of routines during the rearing period reduce fearfulness in adult laying hens?

Exaggerated fear-reactions are associated with injuries, smothering, feather pecking and other events that compromise laying hen welfare. Provision of litter during the rearing period may reduce fearfulness. The aim of this study was to test the hypothesis that chicks with access to litter during the first five weeks of life would be less fearful as adults compared to birds reared without access to litter. The hypothesis was tested in 23 commercial aviary layer flocks in Norway. Five rearing farmers divided the pullets into two groups within their rearing houses. During the first five weeks of life, paper substrate, on which food and other particles could accumulate, covered the wire mesh floor in the treatment group, whereas the control group was reared on bare wire mesh. The egg producers were instructed to follow their normal management procedures. At 30 weeks of age, 23 layer flocks (11 control flocks and 12 paper reared flocks) were visited. A stationary person test and a novel object test were conducted to test fearfulness of the adult hens. In addition, data on provision of environmental enrichment was collected as a binary yes/no variable. Provision of environmental enrichment to adult birds tended to reduce the latency to approach within 2 m of the stationary person (P=0.08). For birds without environmental enrichment as adults, access to litter during rearing increased the number of birds that approached the novel object compared with birds reared without paper (P=0.04). For birds with access to environmental enrichment during production, the access to litter during rearing had no effect on the number of birds that approached the novel object as adult (P=0.99). These results indicate that both providing chicks with paper substrate from the first day of life and providing them with environmental enrichment as adults, are practical and simple alterations of management that reduce fearfulness in laying hens.