Soliman, F. N. K., El-Sabrout, K. 2020. Light wavelengths/colors: Future prospects for broiler behavior and production. Journal of Veterinary Behavior 36, 34-39.

Assessing animal welfare is necessary from animal behavior and product quality/quantity perspectives. Birds have a unique visual system and see in the range of 315-750 nm. Most of their behavior is mediated by vision. Lighting is considered an important exogenous environmental factor that directly affects bird well-being. In broilers, light stimulates and controls feed intake and so affects growth. Recent developments in lighting technology open new possibilities for enhancing the traditional lighting programmes inside poultry houses. Artificial lighting has 3 main aspects: light intensity (brightness), lighting duration (photoperiod), and wavelength (color). The color of light, dictated by the wavelength, exerts variable effects on poultry performance. More than 50% of the broiler studies indicated that blue (450 nm) and green light (550 nm) had positive effects on body weight (>3%), whereas red light (700 nm) increased activity and aggressive behavior of birds (>30%), negatively affecting body weight. Behavioral parameters of broiler chickens, in general, were affected significantly by light colors, whereas slight influences were shown on welfare parameters. This review integrates recent aspects of lighting usage that could influence traits of interest in poultry farming.