Could training affect testing? Investigating the impact of training for the judgment bias test on chicken welfare
Year: 2021
Johanna Neuhauser
University of Veterinary Medicine, Vienna, Austria
Supervisor(s): Dr Sara Hintze, University of Natural Resources and Life Sciences (BOKU), Vienna and Dr Jean-Loup Rault, and Janja Sirovnik University of Veterinary Medicine, Vienna, Austria
Assessment of animals’ emotional states is commonly done using tests which involve extensive training (e.g., cognitive judgement bias tests; JBT). This training, however, may itself affect the animal’s welfare. For example, potentially rewarding training elements (e.g., food rewards) may improve welfare, and conversely, potentially challenging, or stressful elements (e.g., social isolation) may reduce welfare. Furthermore, an effect on welfare could in turn interact with the effect of a studied treatment, influencing the study’s outcome. The aim of the study, therefore, was to investigate the effects of training for a JBT on chicken welfare. Two groups of laying hens were used across two batches: 1) treatment (JBT training and testing; n=16), and 2) control (n=16), with both groups housed together under identical conditions. Treatment hens were trained and tested in a spatial Go/No-go JBT using a four-stage training protocol. Before training began, welfare was assessed for all hens across three behavioural tests: open field, human approach, and tonic immobility tests. After each treatment hen finished JBT testing, welfare of that hen as well as one control hen was assessed again using the same behavioural tests. The study is currently ongoing, with results pending batch-two hens’ completion of the JBT protocol.