Explore the distribution of the chicken eye visual spectrum and its importance in poultry research. Gain key insights into how chickens perceive light and color for better care and management.
Distribution of Chicken Eye Visual Spectrum:
Chickens have four types of cones (red, green , blue , and ultraviolet) , which can sense the spectral range of 300-700nm , far exceeding the human limit of 380-750nm. The “double cones” in their retina can interpret ultraviolet rays and help identify the freshness of food and the health of companions.
Effects of Different Light Spectra on Poultry:
- Ultraviolet Light (350–400 nm)
Function: Activate vitamin D3 synthesis and promote eggshell calcification (eggshell thickness increased by 0.05mm).
Application: 1 hour/day of UV exposure can reduce the soft-shell egg ratio by up to 0.5%. - Blue Light (480–490 nm)
Function: Inhibits the secretion of adrenal cortex hormones , reducing the escape rate of chickens by 70%.
Application: Using a pure blue light environment for 3 days before broiler chickens are released , the tenderness of the meat is increased by 15%.
- Green Light (530–550 nm)
Function: Stimulates muscle growth and satellite cell multiplication, increases broiler growth rate by 10%.
Application: Use green light as the main light (18h/day) in the first two weeks of the brooding period and the weight gain rate will increase by 12%. - Red Light (660–680 nm)
Function: Enhances feed intake by stimulating the hypothalamus , improving daily feed intake by 20%.
Application: During the mating period , 6h/day, red light increases the fertilization rate by 92%.
Requirements for Broiler Lighting Spectrum, Intensity, and Light Cycle
Broiler production is generally divided into two main stages
1、Stage division and spectrum requirements
Growth stage:
Brooding stage: 0-2 weeks
Growing stage: 3 weeks to market
Spectrum selection:
Wavelength range: 415-560 nm (blue to green light)
Effect: Promote broiler growth rate and improve feed conversion efficiency.
Illumination requirements:
Enclosed poultry house (all artificial lighting):
Average illumination: 20-60 lx
Special adjustment: If the chicks come from young breeder flocks and are small, the illumination needs to be increased by 20%-25%.
Semi-enclosed/shading chicken house (natural light + artificial light): 5-10 days old: Gradually reduce the illumination to 5-10 lx to reduce stress.
2、Flicker and Light Uniformity
Flicker Frequency:
Minimum Requirement: ≥300 Hz
(Poultry are 2–3 times more sensitive to flicker than humans the human safety
threshold is 100 Hz).
Illuminance Uniformity over Feed Troughs:
Minimum / Maximum Ratio (U₀): ≥ 0.5
Minimum / Average Ratio (U₁): ≥ 0.7
Objective: To avoid overly bright or dark areas, reduce crowding and feed competition among birds and ensure uniform growth
4、Seasonal and Breed Differences
Breed Adaptation:
Fast-growing broiler breeds (e.g., white-feather broilers) require a higher proportion of blue light (480–500 nm) to promote calmness and weight gain.
Seasonal Impact:
In winter, the light period can be appropriately extended to 18 hours to compensate for insufficient natural light.
Requirements for lighting management of broilers
1. Light intensity:
Brooding period (0-7 days): 20-30 lux (stimulate activity and feeding).
Growing period (8-21 days): 10-20 lux (balance growth and energy consumption).
Fattening period (22 days to market): 5-10 lux (reduce activity and promote weight gain).
2. Lighting time:
Brooding period: 23 hours of light and 1 hour of darkness per day (adaptive strong light environment).
Growing period: gradually shorten to 18 hours of light (simulating natural circadian rhythm).
Fattening period: Use intermittent lighting (such as 1 hour of light + 3 hours of darkness) to reduce energy consumption and improve feed conversion rate.
