Influence of Artificial Lighting on the Performance and Egg Quality of Commercial Layers: a Review

In Brazil, the egg production chain produces fresh eggs for the consumer market and for processing. Layers are housed in battery cage systems. Rearing and development farms are separate from egg-production farms. Considering the recent advance of Brazilian chicken egg production, scientific knowledge on management practices are required to disseminate and to consistently apply this knowledge to improve such practices. Artificial lighting is widely used in poultry reproduction, both in the production of hatchable eggs and of commercial eggs. Light is required for the release of hormones responsible for reproduction; however, the best lighting practices to stimulate laying poultry during the reproductive period still need to be determined, with the aim of saving electric energy, and therefore, to dilute production costs and comply with environmental sustainability requirements. This review showed that layers are indeed photostimulated with more than 12 hours of light, independently of the artificial lighting program applied. Results demonstrate that artificial lighting programs influence egg production, but not egg quality parameters. Intermittent lighting programs are good alternatives when layers are housed in open-sided houses, which are typically used in Brazil. Transcranial light reception is the most important route for the stimulation of reproduction in poultry.