Fearfulness of hens caged individually or in groups in different tiers of a battery and the effects of translocation between tiers.
The responses of laying hens in several fear-eliciting situations were examined. The effects of group-housing and translocation of birds between tiers upon a previously-observed relationship between fearfulness and cage level were assessed. Birds housed in the top tier showed longer durations of tonic immobility, greater avoidance of a novel rod placed in their food trough and decreased approach, activity and vocalisation when placed in a pen containing a novel object, than did their middle-tier counterparts. This relationship, which was common to birds housed either individually or socially, was disrupted by translocation between tiers. The consistently higher fear scores recorded by birds from the top tier are considered likely to reflect differences in general rather than stimulus-specific fearfulness.
D000818:Animals; D002645:Chickens / Q000502:physiology*; D005239:Fear / Q000502:physiology; D005260:Female; D006799:Housing, Animal; D009043:Motor Activity / Q000502:physiology; D014828:Vocalization, Animal