Feed(2700 kcal ofmetabolisable energy/kg, 17.0%crudeprotein,
3.7% Ca, and 0.3% available P) was distributed automatically 3 times
per day at 07:00 h, 15:00 h, and 19:00 h. Hens had permanent access
to the feed. Water was also provided ad libitum. Egg collection was
carried out automatically on a daily basis. Temperature was kept
at 19 ± 1 ◦C. During the light period, artificially maintained from
06:00 h to 23:00 h, average light intensity values in front of the nest
in the cages and in front of the PSA were 2 and 10 lx respectively.