Lighting programs are a key factor for good broiler performance and flock welfare. Lighting
programs are typically designed with changes occurring at predetermined ages and tend to
vary according to the final target market weight of the broilers. Lighting programs designed
to prevent excessive growth between 7 and 21 days have been shown to reduce mortality
due to ascites, sudden death, leg problems and spiking mortality. Research indicates
that lighting programs which include 6 hours of continuous darkness will improve the
development of the immune system.