A set of behavioural tests were carried out over the course of two experiments in order to behaviorally assess the presence of proactive and reactive coping styles in large and small broiler breeder females.

The first experiment included 120 broiler breeder females that were raised at the experimental facilities of Linköping University to 4 weeks of age. At this age 16 small and 16 large broiler breeders were tested in a bag restraint test (BR), a tonic immobility test (TI), an open field test (OF) and a novel object test (NO). 12 of the small birds and 11 of the large birds were also being monitored for home pen activity during the days leading up the behavioural testing

The second experiment took place at a commercial farm and also targeted 4 week old broiler breeder females. As the TI test and the OF test gave the most interesting results in first experiment these were the tests to be carried out also at the farm, and this time included 62 small and 62 large birds. Daily home pen activity monitoring and activity monitoring around a manual restraint test were also performed on 8 small and 9 large birds.