Why do hens sham dustbathe when they have litter
Publication Type: |
Journal Article |
Year of Publication: |
2002 |
Authors: |
I.Anna S Olsson, Linda J Keeling, Ian J.H Duncan |
Publication/Journal: |
Applied Animal Behaviour Science |
Keywords: |
animal welfare, behaviour, dustbathing, motivation, poultry, stimulus |
Abstract:
Hens in cages perform sham dustbathing, that is they go through the behavioural sequence of dustbathing, but on the wire-floor. Such sham dustbathing is found in conventional cages and even in furnished cages which include a dustbath. Consequently, sham dustbathing behaviour cannot be explained only by the absence of litter. Three suggested explanations for sham dustbathing were tested in this study. The first hypothesis was that sham dustbathing satisfies the hens’ motivation for dustbathing behaviour. This hypothesis was investigated by allowing litter-deprived hens to dustbathe, sham dustbathe or simply see dust but not dustbathe, and then measuring dustbathing behaviour when the hens were subsequently given access to litter. No reduction in dustbathing was found after sham dustbathing. The second hypothesis was that sham dustbathing may be the result of social facilitation combined with the fact that the dustbath in furnished cages rarely allows more than one hen to dustbathe at a time. If other hens observing a hen dustbathing in the dustbath become more motivated to dustbathe themselves, they may have to sham dustbathe on the floor. We tested this hypothesis by exposing litter-deprived hens to three different stimuli; hens dustbathing in litter, hens on litter but not dustbathing, and hens without litter and not dustbathing. There was no difference in the amount of sham dustbathing performed by the test hens in the different stimulus situations. Thus, neither the satisfaction from sham dustbathing nor the effect of social facilitation seem to explain why hens sham dustbathe in the presence of a dustbath. If the hens are prevented from dustbathing as chicks, or as pullets when first moved to the furnished laying cages, they may persist in sham dustbathing even if a dustbath is made available to them. The third hypothesis, therefore, was that there is an effect of habit or early experience. To test this hypothesis, hens were deprived of litter until they had developed sham dustbathing and were then given access to litter in a different location to that used for sham dustbathing. In this experiment, six hens (of a total of 26 deprived hens) showed sham dustbathing although litter was available. Thus, some support was found for an effect of habit or early experience on sham dustbathing. This finding is discussed in the light of other research on the effect of experience on dustbathing behaviour.