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Enriched environments keep chickens optimistic

Last changed: 05 July 2018

Chickens living in enriched environments remain happy despite exposure to stress, according to a study from SLU, Linköping University, Uppsala University and Neiker-Tecnalia, Spain. In the study, one group of chickens grew up in rather barren surroundings, and another group in a more complex and stimulating environment.

The optimistic or pessimistic attitude of an individual was tested using a cognitive bias test. Chickens in both types of environments were equally optimistic in the initial tests. It was only after exposure to stress that differences appeared: individuals that had lived in a simpler environment became less optimistic, while chickens in a more complex environment retained their optimistic attitude.

The researchers also measured levels of dopamine in the brain of the chickens. The results showed that chickens assessed to be optimistic had higher levels of dopamine. This suggest that repeated stress can reduce optimism, which could be considered in animal husbandry to provide better welfare.

Link to the publication

https://www.nature.com/articles/s41598-018-23545-6

Reference

Zidar J, Campderrich I, Jansson E, Wichman A, Winberg S, Keeling L, Løvlie H. Environmental complexity buffers against stress-induced negative judgement bias in female chickens. Scientific Reports (2018), DOI: 10.1038/s41598-018-23545-6