4-year PhD Studentship: Measurement of reward sensitivity as an indicator of welfare in chickens
Bristol Veterinary School, University of Bristol
Bristol, United Kingdom
Humans show a reduction in sensitivity to reward when suffering from clinical depression and similar changes have been demonstrated in laboratory rodents used as models for depression. This reduced sensitivity is known as anhedonia – loss of pleasure - and has been operationalized as a measure of negative affect and poor welfare in rodents using sucrose preference tests, in which animals living in threatening or stressful circumstances reduce the volume of sucrose solution they drink during a fixed time period, and lower their preference for consuming sweetened over non-sweetened water. In recent years, however, research has shown that these traditional tests of anhedonia can be improved upon considerably by more efficient and reliable methods of hedonic assessment, based on the finding that rodents show stereotyped, rythmic and highly quantifiable patterns of licking behaviour (‘lick cluster size’) when drinking water and other palatable solutions. The assessment of reductions in reward sensitivity in non-rodents whose welfare is compromised is now a growing field, but to date, no detailed investigations have been made of the relationship between anhedonic processes and welfare in non-mammalian species (e.g. chickens, a species of major welfare concern).
Supervisors: Dr Elizabeth Paul (primary supervisor), Dr Joanne Edgar, Dr Laszo Talas, Dr John Fennell