Animals must not be kept in conditions of constant darkness (Art. 151, item 7 of the AIA) or without a break from lighting.

Where possible the use of natural light to satisfy the physiological needs of the birds is desirable, but appropriate artificial lighting must also be provided.

Birds should be placed in a light that is good for them allows them to see clearly and stimulates their activity. Must be used a lighting system that provides a level of light from 20 lux. Light level above 20 lux will stimulate the activity of the birds. The light distribution in the rooms must be even. If behavioral problems, such as cannibalism, occur, it can be reduced the level of illumination for several days.

All buildings shall have light with an intensity of at least 20 lux during the light periods, measured at the level of the birds’ eyes, which illuminates at least 80% of the usable area. Where necessary, temporary reduction of the level of illumination may be permitted in accordance with veterinary recommendations. Within seven days of the time of laying the chickens in the building and up to three days before the expected time of slaughter, the light must follow a 24-hour rhythm and include periods of darkness lasting at least 6 hours in total, with at least one period of continuous darkness. of at least 4 hours, excluding periods of eclipse.

Longer periods of darkness can reduce mortality and have a beneficial effect on foot health.