Photoperiod Management
Artificial lighting programs significantly influence egg production by regulating reproductive hormones. Layers require a minimum of 12–14 hours of daily light to stimulate egg-laying, with longer photoperiods (e.g., 16–18 hours) improving production rates in both chickens and turkeys. For example, extending daylight to 18 hours in turkeys reduced photorefractoriness and increased egg production by 14 eggs/hen compared to 15-hour cycles. Intermittent lighting (e.g., alternating light-dark periods) can also enhance feed efficiency and egg weight without compromising production.
Light Wavelength and Spectral Effects
Red light (660 nm) is particularly effective in stimulating the hypothalamus, promoting sexual maturity, and increasing egg production compared to blue, green, or white light. Ultraviolet (UV) light improves eggshell quality by activating vitamin D synthesis, though it has minimal direct impact on laying rates. Monochromatic LED lighting, especially red and white spectra, matches or exceeds traditional incandescent and fluorescent lights in maintaining egg production while reducing energy use.
Light Source Efficiency and Performance
LED lighting systems outperform fluorescent and incandescent lamps in energy efficiency, durability, and adaptability. Studies show LED-lit hens achieve comparable egg production to fluorescent-lit counterparts, with additional benefits such as reduced energy consumption (28–33% savings) and longer operational lifespans. However, LED lights may slightly reduce eggshell thickness in certain breeds (e.g., W-36 layers).
Light Intensity and Zoning
Optimal light intensity varies by activity area: feeding zones require ≥20 lux to maximize feed intake and attract hens, while resting areas can operate at ≤5 lux without disrupting behavior. Overly intense lighting (>567 lux) may reduce egg weight in turkeys, whereas lower intensities (22 lux) improve egg size.
Behavioral and Welfare Considerations
Dynamic lighting mimicking natural daylight cycles supports circadian rhythms, reducing stress and improving laying persistency. For example, fluctuating light programs (e.g., alternating between 2 W/m² and 6 W/m²) enhance feed conversion ratios and egg weight in layers. Additionally, UV-enriched environments (via natural or artificial sources) improve shell quality and hen welfare.
Practical Recommendations
Adopt LED Systems: Prioritize red or white LEDs for energy savings and reproductive stimulation.
Tailor Photoperiods: Implement 14–16 hours of daily light, adjusting seasonally to maintain production.
Monitor Intensity: Use lux meters to ensure proper illumination in feeding and nesting areas.
Incorporate UV Light: Enhance shell quality in systems lacking natural sunlight.
By integrating these evidence-based strategies, poultry producers can optimize egg yield, reduce costs, and improve sustainability.