2.1.2. Experiment 2
Eighteen layer hens (6 per time cohort) were randomly selected from a commercial egg farm in Kinglake, Victoria. All hens were Hyline Brown and 76 wk of age. The cages were located in a climate-controlled shed for temperature, light, and ventilation. The thermostats were set at 23°C with the mean temperature maintained at 21°C during the dark period and 25°C during the light. Lighting was provided by incandescent bulbs and controlled by a computer. The light period was from 7 AM to 7 PM. All procedures were conducted within the environmentally controlled laying shed.
2.1.2.1. Food and water deprivation
At 0 h, hens were deprived of food and water, and the 0 h group was sampled. Six hens were sampled after 12 h of food and water deprivation, 12 h group, and 6 hens were sampled after 24 h of food and water deprivation, 24 h group.