Many of the physiological processes in poultry are influenced
by light. Egg production and quality may be influenced by visible
spectrum emitted by the light source, and some colors may be more
stimulating than others (Nicholls et al., 1988). Each light bulb type
used for artificial lighting in poultry houses has a different visible
spectrum, but Etches (1996) found that poultry respond to most
spectra commonly provided, independently of lamp type (fluorescent,
incandescent, sodium vapor).