Welfare-improving enrichments greatly reduce hens' startle responses, despite little change in judgment bias.

ABSTRACT: Responses to ambiguous and aversive stimuli (e.g. via tests of judgment bias and measures of startle amplitude) can indicate mammals' affective states. We hypothesised that such findings generalize to birds, and that these two responses co-vary (since both involve stimulus evaluation). To validate startle reflexes (involuntary responses to sudden aversive stimuli) and responses in a judgment bias task as indicators of avian affective state, we differentially housed hens with or without preferred enrichments assumed to improve mood (in a crossover design). To control for personality, we first measured hens' baseline exploration levels. To infer judgment bias, control and enriched hens were trained to discriminate between white and dark grey cues (associated with reward and punishment, respe

SUBMITTER: Ross M 

PROVIDER: S-EPMC6695442 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature