Methodologies for assessing domestic hens' preferences for sounds
Jones, A. R. (2011). Methodologies for assessing domestic hens’ preferences for sounds (Thesis, Doctor of Philosophy (PhD)). University of Waikato, Hamilton, New Zealand. Retrieved from http://hdl.handle.net/10289/5963
Permanent Research Commons link: http://hdl.handle.net/10289/5963
A series of five experiments assessed the effects of different sounds on the choice behaviour of domestic hens and chicks using a range of procedures. The first experiment compared the effects of white noise on hens’ performance under multiple-concurrent schedules with those of other sounds (an alarm call, the sounds of hens feeding and a food call) with the same subjects. The sound was shown to bias responding of hens away from the keys associated with all sounds and the magnitude of this bias was largest for white noise and the food call. Different to the other sounds, white noise suppressed the responding of hens when it was present, thus confounding response allocation. In Experiment 2, a concurrent-chains procedure was used to assess hens’ preferences for the same sounds used in Experiment 1. Sound was associated with one terminal-link and hens made a choice between sound and no sound alternatives in the absence of sound. The direction of noise biases from responding in the initial-links was the same across hens for one sound only (food call) but the magnitude of these biases varied. This was different from Experiment 1 but terminal-link responding was suppressed in the presence of sound, as in Experiment 1. Terminal-link entry pauses also tended to be longer in terminal-links that contained most sounds but the effect was greater with white noise and the food call. A conditioned place preference procedure was used in Experiment 3 to assess chicks’ preferences for places associated with sounds, in the absence of reinforcement or sound. Baseline preferences were assessed by measuring time spent in each compartment of a 3-compartment chamber. Groups of chicks were then conditioned to either food or a sound by being confined in one compartment. The chicks’ post-conditioning test sessions showed a significant conditioned place preference towards the area associated with food and away from the area associated with white noise. This experiment showed that the conditioned place preference procedure could be used to assess the conditioning effects of sound and food on domestic hen chicks and confirms the results found with white noise. As all previous experiments identified sounds that were only not preferred, Experiment 4 attempted to make a preferred sound for hens by associating a pure tone with food. Preference for this tone was assessed in the same manner as Experiment 1. The direction of preferences across subjects was inconsistent, thus this experiment was not successful. One possible reason for the inconsistent results could have been the use of a pure tone. Experiments 1 and 2 showed that white noise and the food call affected responding of hens and so it was thought possible that associating these sounds with food would increase preferences towards them. Thus, Experiment 5 used the same procedure as Experiment 4 to associate food with white noise and a food call. Two training phases, one with food and one without food, increased noise biases away from the keys associated with sound during the preference assessment. It was theorised that the training phase made sound unpredictable and the hens no longer had control over its presence or absence, therefore making the sound less preferred and more aversive. Overall, the results of this thesis suggest that white noise is an aversive stimulus for domestic fowl and that concurrent schedules and the conditioned place preference procedure could be used with other species to assess their preferences for environmental stimuli, which would provide information that may aid in improving their welfare.
University of Waikato
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