Research note: Pulsed alternating wavelength system (PAWS) may aid in the maintenance of laying hen skeletal quality throughout a lay cycle

Adequate light is required for normal development of the skeletal system in laying hens. A novel lighting system, Pulsed Alternating Wavelength System (PAWS), has been developed for the poultry industry. Through production-specific lighting recipes, PAWS may improve the growth rate, welfare, and productivity of poultry species, including laying hens. Since the skeleton plays a crucial role in egg production, determining how PAWS can impact bone quality in laying hens is essential. The objective of this project was to evaluate the effects of two PAWS lighting recipes on the skeletal quality of commercial, conventionally-caged laying hens. Three flocks at a commercial facility housed under either control lighting (CON) or different PAWS recipes (PAWS1 or PAWS2) were followed throughout a lay cycle. The femur, tibia, and humerus were assessed for digital bone mineral density and content (dBMD; dBMC), and biomechanical properties from 3-point bending. At the post-peak production phase, PAWS1 did have greater femur flexural strength (P = 0.031) and greater humerus Young's modulus (P = 0.031) compared to CON hens. From peak to post-peak production, the tibia fracture force and flexural strength remained consistent in PAWS1 hens (P > 0.100), but declined in CON hens (P < 0.002). Hens exposed to PAWS1 had improved bone strength properties during post-peak production, and maintained structural integrity of the tibia while strength and integrity declined in CON hens. The PAWS2 bone quality properties were consistent from peak production to post-molt, with few exceptions, however, this was likely due to the act of molting rather than the lighting type. The novel lighting shows promise in improving layer bone quality, warranting research in cage-free environments.