Houses where the amount of light entering the building from outside exceed 0.5 lux should be
considered as semi-dark, and the lighting program to be used should be designed for natural light
exposure and follow the schedule for open-sided houses.
The lighting schedule used should take into account the natural day length at the time the flock is 140
days of age in order to get effective photo stimulation and to avoid too early maturity. Total light
duration must never be shorter than the longest natural day in the period between 8 weeks of age and
light stimulation to avoid any increase of the light duration before 20 weeks old.