Impact of lighting on poultry reproduction and recent advances.

Abstract

Different wavelengths of visible light spectrum influence the reproductive system of domestic avian species. Light perceived by the retina is involved in growth and behaviour whereas light perceived by the hypothalamus is involved in reproduction through photosensitive cells in the brain (extraretinal photoreceptors) and it varies with intensity of different wavelengths of light. Red spectrum of light with 675 nm of wavelengths is more gonadostimulatory than shorter wavelengths of 450-475 nm of light. Recent studies indicate that the hypothalamic opsins are involved in avian photoreception. Non-mammalian vertebrates detect light by deep brain photoreceptors that lie outside the retina and pineal gland to regulate seasonal cycle of reproduction. It was reported that opsin is a deep-brain photoreceptive molecule in the avian brain that regulate seasonal reproduction in birds. Lighting recommendations should be based on local environmental conditions, house type, light requirements for pullets, growers, broilers, layers and overall stockman objectives. Lighting programmes that are inappropriately employed may impair average daily gain and compromise flock performance. Careful observations of flock performance, nutrient density and intake are also important in designing lighting programmes in broilers. Layer and broiler lighting programmes in concert with the proper genetics, environment, nutrition and management create the best in welfare for the animal and performance for the integrator. Light-emitting diode (LED) lighting in poultry facilities is cost effective and could increase egg production in layers and early body weight gain in broilers exposed to red and green LED light, respectively .