130 eggs and 130 day old chickens were obtained from Gimranäs AB commercial hatchery. Eggs collected on day 19 of incubation and were transported in a portable incubator with a thermostat to maintain a temperature of 37°C throughout the three hour journey to Linköping University (LiU) hatchery. The eggs were then placed in a hatching incubator set to 37.5°C. Day old chickens were collected from the same commercial hatchery three days later immediately after completing the commercial hatchery process and then transported for three hours to LiU hatchery. All chickens were Lohmann Selected Leghorn strain from Lohmann Tierzucht, Germany grandparental stock. All chickens were wing marked at eight days old after the first round of behavioural tests had concluded. At this stage control chickens were vaccinated, the hatchery chickens underwent pseudo-vaccination to maintain similarity of treatment between groups. A total of 83 control chickens and 85 hatchery chickens remained after week 1 testing; birds not used in tests were culled.  On week six of the experiment all chickens were transported from the chicken hatchery facility to the adult chicken facility, remaining in the same flock as the previous facility.