Consistency, transitivity and inter-relationships between measures of choice in environmental preference tests with chickens.

Choice experiments are a widespread method of assessing the welfare requirements of domestic animals but prior predictions about what animals should choose to maximise their welfare are not possible. It is therefore important to analyse the data from sets of choice tests to establish whether intra-set and inter-set consistency in choice occurs. Strong inter-set consistency (transitivity) would provide support for the assumption that animals are maximising a complex utility (welfare) that may map onto their subjective state.