Two of the primary goals of layer and breeder hen management are to stimulate and maintain egg laying performance, and to enhance bird welfare. Commercial layers and breeders (and all other poultry strains) are highly photosensitive, and it is critical that an optimal lighting environment is provided in housing facilities to optimize performance and welfare.
Poultry perceive light visually through photoreceptors in their eyes, and non-visually through photoreceptors in their brain. Visual photoreception gives birds the capacity to respond to the surrounding environment by facilitating sight. Although nonvisual photoreception doesn’t contribute to sight, it stimulates many physiological processes in the body, such as the reproductive axis, immune system, metabolism, and circadian rhythm (Cassone, 2014). For photoreceptors in the brain to be activated, light must penetrate through the many layers of feathers, skin, and bone to reach the brain. Poultry can perceive a wide range of light wavelengths, from UV-A to far-red wavelengths. Light wavelengths in the red portion of the light spectrum can most effectively penetrate through tissues to reach non-visual photoreceptors in the brain. Long light wavelengths, such as those perceived as red light, have a lower frequency than short light wavelengths, such as those perceived as blue light. Compared to short wavelengths at the same intensity, long (red) wavelengths interact less with their travel medium - whether this medium is air, skin, feathers, or bone - and will travel further than short wavelength light.
Several scientific publications have demonstrated the advantages of using red-enhanced lighting for layers and breeders. Baxter et al. (2014) concluded red light is required to stimulate the reproductive axis, and that the effects of red light do not require a functional retina. Other studies have concluded that exposing birds to red light resulted in better early laying performance (Huber-Eicher et al., 2013; Grongruttananun and Guntapa, 2012), and reduced physiological indicators of stress (Archer, 2019).
Red light plays an integral role in the performance and welfare of laying and breeder hens. The ONCE Dim-To-Red spectrum provides a dynamic light spectrum that ensures adequate red-light exposure at every light intensity. As the light intensity is reduced, Dim-to-Red reduces the concentration of white light, producing a highly concentrated red spectrum to mimic sunrise and sunset, ensuring daily circadian entrainment for biorhythms and egg laying behaviors. With the integration of monochromatic red LEDs, the Dim-to-Red spectrum can additionally be used as a tool to reduce feather picking and cannibalistic behaviors by masking existing wounds on white or brown feathers.
Citations
Archer, G.S., 2019. How does red light affect layer production, fear, and stress? Poult. Sci. 98: 3-8.
Baxter, M., N. Joseph, V. Osborne, and G. Bedecarrats. 2014. Red light is necessary to activate the reproductive axis in chickens independently of the retina of the eye. Poult. Sci. 93:1289-1297.
Cassone, V. M. 2014. Avian circadian organization: A chorus of clocks. Front. Neuroendocrin. 35:76-88.
Gongruttananun, N. and Guntapa, P. 2012. Effects of Red Light Illumination on Productivity, Fertility, Hatchability and Energy Efficiency of Thai Indigenous Hens. Agriculture and Natural Resources. 46: 51-63.
Huber-Eicher, B., Suter, A. and Spring-Stähli, P. 2013. Effects of colored light-emitting diode illumination on behavior and performance of laying hens. Poult. Sci. 92: 869-873.