Lighting Programs for Laying Hens: Optimizing Egg Production

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-14

Key Takeaways

• Optimal egg production in laying hens is critically dependent on a consistent photoperiod of 14 to 16 hours of light daily, with no decrease during the laying cycle, to maintain reproductive hormonal stimulation.
• Light intensity should be maintained between 10 to 30 lux (approximately 1 to 3 foot-candles) at bird eye level; exceeding this range can induce behavioral issues like feather pecking and cannibalism, while insufficient light (<5 lux) will impair egg laying.
• A step-up lighting program for pullets, commencing at 16-18 weeks of age and increasing light by 15-30 minutes weekly until 14-16 hours is achieved, is standard practice to synchronize sexual maturity with adequate body weight and skeletal development.
• Light color influences behavior; warm white (2700K-3000K) or incandescent bulbs are effective, while blue or green light may have calming effects, and red light should be strictly avoided due to its propensity to incite feather pecking and cannibalism.
• Maintaining consistent light schedules via reliable timers with battery backup is paramount, as erratic light exposure can trigger molting and significantly disrupt egg production cycles.
• Regular cleaning of bulbs and fixtures is essential, as dust and dirt accumulation can reduce light output by up to 50%, directly impacting the effectiveness of the lighting program.

Light is the single most important environmental factor controlling egg production in laying hens. This guide explains how light intensity, duration, and consistency influence the reproductive cycle of hens, and it provides a practical, step-by-step approach to designing and managing a lighting program for your flock. Whether you manage a small backyard coop or a commercial layer facility, this article covers the science behind photoperiods, gives specific recommendations for light levels and schedules, and helps you troubleshoot common lighting-related problems.

At a Glance

• Hens need 14 to 16 hours of light per day to maintain maximum egg production. The photoperiod must never decrease during the laying period.
• Light intensity for laying hens should be 10 to 30 lux (about 1 to 3 foot-candles) at bird eye level. More light is not better and can cause behavioral problems.
• Use a timer to provide a consistent, non-staggered light schedule. Manual switching leads to erratic production and molting.
• A step-up lighting program is the standard approach. Start pullets on 8 hours of light and increase by 15 to 30 minutes per week until you reach 14 to 16 hours.
• Do not increase the photoperiod before 16 to 18 weeks of age unless the pullets have not reached target body weight.
• Light color matters. Warm white or incandescent bulbs are effective. Some studies suggest blue or green light can be calming, but red light should be avoided because it encourages feather pecking and cannibalism.
• Clean bulbs and fixtures regularly. Dust and dirt can reduce light output by up to 50 percent.
• Keep detailed records of your lighting schedule, bulb wattage, light intensity readings, and egg production. This data helps you diagnose problems quickly.
• If egg production drops suddenly, check your lighting system first, then look for disease, stress, or nutritional issues. Contact a veterinarian if the drop is severe or accompanied by other signs of illness.

Understanding the Role of Light in Egg Production

Light is the primary environmental cue that regulates the reproductive system of chickens. The eye is not the only light receptor in a hen. Light also penetrates the skull and reaches the pineal gland and the hypothalamus directly. These light-sensitive tissues trigger a hormonal cascade that controls ovulation and egg laying.

In natural conditions, hens begin laying in spring when daylight hours increase. As the days lengthen, the hypothalamus signals the pituitary gland to release hormones that stimulate the ovary. The ovary then produces eggs on a regular cycle. When daylight hours decrease in late summer and fall, hens naturally slow or stop laying and may go through a molt.

Commercial lighting programs manipulate this natural response. By controlling the photoperiod, or the daily period of light exposure, you can encourage hens to lay consistently throughout the year. The key principle is that hens need a certain minimum amount of light to trigger and maintain egg production, and that light period must be stable or gradually increasing.

The Hormonal Cascade

When light enters the hen's brain, it stimulates the hypothalamus to release gonadotropin-releasing hormone. This hormone travels to the pituitary gland, which then releases two important reproductive hormones: follicle-stimulating hormone and luteinizing hormone. Follicle-stimulating hormone causes ovarian follicles to develop and mature. Luteinizing hormone triggers ovulation, the release of the yolk from the ovary.

This entire process takes time. When you increase the photoperiod, you will not see an immediate jump in egg production. It typically takes two to three weeks for the hormonal changes to result in a visible increase in egg output. This lag time is important to remember when you are adjusting your lighting program or troubleshooting a production problem.

Photorefractoriness

Hens have a natural limit to how long they can respond to light stimulation. After a prolonged period of long days, hens become photorefractory. This means the reproductive system no longer responds to the light stimulus, and egg production declines. In commercial operations, hens are typically kept for one laying cycle of about 60 to 80 weeks. After that, they are molted or replaced because photorefractoriness makes further production uneconomical.

You can delay photorefractoriness by keeping the photoperiod stable once it reaches its maximum. Do not increase light hours beyond 16 per day. There is no benefit to providing more than 16 hours of light, and it can increase the risk of photorefractoriness and behavioral problems.

Designing a Lighting Program for Pullets

The lighting program for laying hens actually begins when the birds are still pullets. The way you light young birds determines how well they will respond to the laying photoperiod later. The goal during the pullet phase is to delay sexual maturity until the bird has reached adequate body weight and skeletal development. Premature sexual maturity leads to small eggs, poor shell quality, and a higher incidence of prolapse.

The Step-Down Program

For the first 48 to 72 hours of life, chicks need near-continuous light to help them find feed and water. Provide 22 to 24 hours of light at 30 to 40 lux for the first two to three days. After this initial period, gradually reduce the photoperiod.

A common step-down program starts with 20 hours of light at one week of age and reduces the photoperiod by 1 to 2 hours per week until the birds are on 8 hours of light by 8 to 10 weeks of age. This mimics the decreasing day length of late summer and early fall, which naturally delays sexual maturity.

The exact schedule depends on the season and the housing type. In open-sided houses, natural daylight will be part of the equation. In light-controlled houses, you have full control over the photoperiod.

The Step-Up Program

At 16 to 18 weeks of age, or when the pullets have reached target body weight, begin increasing the photoperiod. Increase the light by 15 to 30 minutes per week until you reach 14 to 16 hours of light per day. This step-up mimics the increasing day length of spring and signals the reproductive system to begin maturing.

The first egg will typically appear two to three weeks after the first light increase. Peak production, which should be around 90 percent or higher, is typically reached four to six weeks after the first egg.

Body Weight Considerations

Body weight is more important than age when deciding when to start the step-up program. If pullets are underweight at 16 weeks, delay the light increase until they reach target weight. Giving light stimulation to underweight birds will cause them to lay small eggs and may lead to prolapse or a poor peak.

Weigh a sample of birds weekly during the pullet phase. Many producers weigh 25 to 50 birds per flock and compare the average weight to the breed standard. If the flock is more than 10 percent below target, delay the light increase and address the underlying nutritional or health problem first.

Light Intensity for Layers

Light intensity is measured in lux or foot-candles. One foot-candle equals approximately 10.76 lux. For practical purposes, many producers use the rough conversion of 1 foot-candle equals 10 lux.

The recommended light intensity for laying hens is 10 to 30 lux (about 1 to 3 foot-candles) at bird eye level. This is roughly equivalent to the light level of a well-lit room in a house. Levels below 5 lux will not adequately stimulate egg production. Levels above 30 lux do not increase egg production further, and they can increase the risk of feather pecking, cannibalism, and nervousness.

Measuring Light Intensity

Do not guess at light levels. Use a light meter to measure intensity at bird eye level. Hold the light meter at the height of the hens' heads and take readings at multiple locations throughout the house. Light levels will vary depending on the distance from the bulbs, the presence of shadows, and the cleanliness of the fixtures.

Take readings at the feeder line, the drinker line, and in the middle of the pen. Aim for uniform light distribution. A variation of more than 20 percent between the brightest and darkest areas can cause hens to crowd in the brighter areas or avoid certain parts of the house.

Bulb Selection and Placement

Incandescent bulbs provide a full spectrum of light that is well suited for poultry. However, they are energy-inefficient and are being phased out in many regions. Compact fluorescent lamps and LED bulbs are effective alternatives.

Choose bulbs with a color temperature between 2700K and 3000K, which produces a warm white light. Some research suggests that hens perceive light differently across the spectrum. Blue and green light can have a calming effect and may reduce feather pecking. Red light should be avoided because it can increase cannibalism.

Place bulbs so that light is distributed evenly. In a typical layer house, bulbs are spaced 8 to 12 feet apart and mounted 6 to 8 feet above the floor. Use reflectors to direct light downward and increase efficiency.

Light Intensity by Age

Chicks need higher light intensity than adult hens. During the first week, provide 30 to 40 lux to help chicks find feed and water. From week two through the pullet phase, reduce intensity to 10 to 20 lux. During the laying period, maintain 10 to 30 lux.

Some producers use dimmers to gradually adjust light intensity. This is useful for reducing stress during flock checks or when entering the house. However, do not reduce light intensity below 5 lux during the laying period, as this can cause a drop in production.

Step-by-Step Guide to Setting Up a Lighting Program

Follow these steps to establish a lighting program for your laying flock. The exact numbers will vary depending on your housing type, breed, and management goals, but the principles remain the same.

Step 1: Determine Your Housing Type

The first decision is whether your birds are in a light-controlled house or an open-sided house with natural light.

In a light-controlled house, you have full control over the photoperiod. This is the most reliable system for maintaining year-round production. You can black out windows and use artificial light exclusively, or you can supplement natural light with artificial light.

In an open-sided house, you must work with natural day length. This is more challenging because day length varies with the season. In the summer, days are long and may exceed the recommended 16 hours. In the winter, days are short and you will need to supplement with artificial light.

Step 2: Choose Your Timer System

An automatic timer is essential for consistent light control. Choose a timer that can be set in 15-minute increments and has a battery backup. Astronomical timers that adjust for sunrise and sunset are useful for open-sided houses.

Do not rely on manual switching. Hens are very sensitive to changes in the light schedule. A single day of inconsistent lighting can cause a temporary drop in egg production. Erratic light schedules can trigger a molt.

Step 3: Set the Photoperiod for the Laying Period

For most laying flocks, the target photoperiod is 14 to 16 hours of light per day. This provides enough light to maintain egg production without causing excessive stress or photorefractoriness.

If you are using a single fixed photoperiod, 15 hours is a reasonable middle ground. If your house has natural light, you may need to adjust the photoperiod seasonally. In the summer, you might need to black out the house to prevent day length from exceeding 16 hours. In the winter, you will need to supplement with artificial light to maintain the minimum photoperiod.

Step 4: Design the Step-Up Schedule

If you are raising your own pullets, design a step-up schedule that takes you from the pullet photoperiod to the target laying photoperiod.

Example schedule:

• Week 16: 8 hours of light
• Week 17: 8 hours 30 minutes
• Week 18: 9 hours
• Week 19: 9 hours 30 minutes
• Week 20: 10 hours
• Continue adding 30 minutes per week until you reach 15 hours at approximately week 33.

The exact timing depends on when the birds reach target body weight. Do not start the step-up before 16 weeks of age, and do not delay it past 20 weeks if the birds are at target weight.

Step 5: Install and Position Lights

Install bulbs with reflectors to maximize light output. Position bulbs so that light is distributed evenly throughout the house. Take light meter readings at bird eye level and adjust bulb placement or wattage until you achieve 10 to 30 lux in all areas.

Use a light meter to verify intensity. Do not estimate based on bulb wattage alone. A 60-watt incandescent bulb in a dirty fixture may provide less light than a clean 25-watt bulb.

Step 6: Establish a Daily Routine

Set the timer so that lights come on at the same time every day. The exact time does not matter as long as it is consistent. Many producers choose to have lights come on before dawn and turn off after dusk, which allows for natural light during the day.

Keep the light schedule constant throughout the laying period. Do not change the schedule for convenience or to save electricity. Consistency is the key to maintaining egg production.

Step 7: Monitor and Adjust

Monitor egg production daily and compare it to the breed standard. If production drops, check the lighting system first. Verify that the timer is working correctly, that bulbs have not burned out, and that light intensity is still adequate.

Keep a log of light meter readings, bulb changes, and any adjustments to the schedule. This record will help you identify patterns and diagnose problems.

Common Mistakes in Poultry Lighting Management

Many producers make avoidable mistakes that reduce egg production. Here are the most common problems and how to avoid them.

Inconsistent Light Schedules

The most common mistake is inconsistent lighting. This happens when producers rely on manual switching, when timers fail, or when power outages occur. Hens are extremely sensitive to photoperiod changes. A single long day can cause hens to lay earlier in the day, and a single short day can cause a temporary drop in production.

Use a reliable timer with a battery backup. Check the timer weekly to ensure it is still set correctly. If you experience a power outage, restore the light schedule as soon as possible. If the outage lasted more than a few hours, you may need to gradually adjust the schedule back to normal rather than making a sudden change.

Excessive Light Intensity

More light is not better. High light intensity above 30 lux increases activity, which can lead to feather pecking, cannibalism, and stress. It also increases the risk of prolapse in young hens.

If you see feather pecking or aggressive behavior, check the light intensity. Reduce it to the lower end of the recommended range, around 10 lux, and observe the birds for a few days.

Inadequate Light Intensity

The opposite problem is light levels that are too low. This happens when bulbs are dirty, when too many bulbs have burned out, or when the house is too large for the number of fixtures. Light levels below 5 lux will not adequately stimulate egg production.

Clean bulbs and fixtures every two to four weeks. Dust and dirt can reduce light output by as much as 50 percent. Replace burned-out bulbs promptly and keep spare bulbs on hand.

Starting the Step-Up Too Early

Some producers increase the photoperiod too early, hoping to bring birds into production faster. This is a mistake. Pullets that are light-stimulated before they reach target body weight will produce small eggs and may develop prolapse. They may also have a poor peak and a rapid decline in production.

Wait until the pullets are at least 16 weeks old and at target body weight before starting the step-up program. If you are unsure about body weight, consult the breed standard or your feed supplier.

Ignoring the Season

In open-sided houses, producers often forget that natural day length changes throughout the year. In the summer, day length may exceed 16 hours, which can cause hens to go into a molt prematurely. In the winter, day length drops below the minimum needed for production.

In open-sided houses, you may need to black out the house in the summer to prevent excessive day length. In the winter, you must provide supplemental light to maintain a minimum of 14 hours of light per day.

Using the Wrong Light Color

The color of light matters. Red light can increase aggressive behavior and cannibalism. Blue and green light are calming. Warm white light is a safe choice that works well for most flocks.

If you are experiencing behavioral problems, consider switching to blue or green bulbs. Some producers report that these colors reduce feather pecking and improve feed conversion.

Decision Thresholds for Lighting Adjustments

Knowing when to adjust your lighting program is as important as knowing how to set it up. Use these thresholds as a guide for making management decisions.

Egg Production Below 50 Percent

If egg production drops below 50 percent and you cannot identify a disease or nutritional cause, check the lighting system. Verify that the photoperiod is still at the target level and that light intensity is adequate. If both are correct, consider whether the hens are becoming photorefractory. If the flock is older than 60 weeks, a molt may be necessary.

Egg Production Drop of More Than 10 Percent in One Week

A sudden drop in production of more than 10 percent in a single week is a red flag. Check the lighting system first, then look for other causes such as disease, water deprivation, feed problems, or extreme stress. If you cannot identify the cause within 48 hours, contact a veterinarian.

Delayed Onset of Production

If pullets have been on a step-up program for three weeks and have not started laying, check the following:

• Is the photoperiod actually increasing? Verify the timer is working.
• Are the pullets at target body weight? Underweight birds will delay production.
• Is there a disease problem? Respiratory diseases can delay onset of lay.
• Is the light intensity adequate? Measure it with a light meter.

If you cannot identify the cause, consult a veterinarian or your extension agent.

Molting Triggered by Light Changes

If hens go into a molt unexpectedly, it is often because the photoperiod decreased. This can happen if a timer fails, if a power outage occurs, or if the producer accidentally changes the schedule. Restore the correct photoperiod immediately. It may take several weeks for production to recover.

Monitoring and Recordkeeping

Good recordkeeping helps you identify problems early and make informed management decisions. Keep the following records for each flock.

Daily Records

• Egg production: number of eggs laid per day and percentage production
• Mortality: number of dead birds and causes if known
• Feed consumption: amount of feed used per day
• Water consumption: any significant changes
• Light schedule: confirm the timer is working and the schedule is correct

Weekly Records

• Average body weight for a sample of birds
• Egg weight and shell quality
• Light intensity readings at multiple locations
• Any behavioral observations such as feather pecking or cannibalism

Flock Records

• Breed and age of the flock
• Vaccination history
• Feeding program and feed analysis
• Any disease or health problems
• Lighting program details including bulb type, wattage, and placement

Review your records weekly and compare them to the breed standard. A gradual decline in production after peak is normal. A sudden drop is cause for investigation.

Troubleshooting Lighting Problems

When egg production drops unexpectedly, work through this checklist to rule out lighting problems.

Check the Timer

Verify that the timer is set correctly and is actually switching the lights on and off. Test the timer by watching it through a full cycle. Check the battery backup and replace it if needed.

Check the Bulbs

Walk through the house and look for burned-out bulbs. Replace any that are not working. Check for flickering bulbs, which indicate a failing bulb or a loose connection.

Clean the Fixtures

Dirty bulbs and reflectors reduce light output significantly. Clean all fixtures and replace any damaged reflectors.

Measure Light Intensity

Use a light meter to measure intensity at bird eye level in multiple locations. Compare your readings to the recommended range of 10 to 30 lux. If intensity is below 10 lux, add more bulbs or increase wattage.

Verify the Photoperiod

Confirm that the lights are on for the correct number of hours per day. Check that the lights come on and go off at the same time every day. If the schedule has drifted, reset the timer.

Check for Natural Light Intrusion

In light-controlled houses, check for light leaks around doors, vents, and windows. Even small amounts of light can affect the photoperiod. Seal any leaks you find.

Observe Bird Behavior

Watch the birds at various times of day. Are they active and eating normally? Are they crowding in one area, which might indicate a lighting problem? Are they showing signs of stress such as feather pecking or pacing?

When to Call a Veterinarian or Extension Agent

Lighting problems can sometimes mask or coincide with health problems. Contact a veterinarian or your extension agent in the following situations.

Sudden or Severe Production Drops

If egg production drops by more than 20 percent in a few days, or if the drop is accompanied by other signs of illness, contact a veterinarian immediately. Infectious diseases such as infectious bronchitis, Newcastle disease, and avian influenza can cause rapid production drops.

Increased Mortality

If you see an increase in mortality, especially if it is sudden, contact a veterinarian. Do not wait to see if the problem resolves on its own.

Signs of Respiratory Disease

Coughing, sneezing, nasal discharge, and difficulty breathing are signs of respiratory disease. These conditions require prompt veterinary attention.

Behavioral Problems

If feather pecking or cannibalism becomes severe, contact a veterinarian or extension agent. These problems can spread quickly through a flock and cause significant losses.

Regulatory Concerns

If you suspect a reportable disease such as avian influenza, contact your state veterinarian or the USDA APHIS office immediately. Do not move birds or equipment off the farm until you have been advised to do so.

Lighting Programs for Different Production Systems

The basic principles of lighting are the same for all production systems, but the specific program varies depending on housing type.

Cage Systems

In cage systems, light distribution is relatively even because birds are confined to a small area. Place bulbs in the aisles between cage rows to provide uniform light. Check light intensity at the feed trough level, which is where the hens' heads will be.

Barn and Aviary Systems

In barn systems, birds have more space and can move away from or toward light sources. Pay attention to light distribution and avoid dark corners where hens may hide. Provide adequate light in all areas, including the litter area and perches.

Free-Range Systems

Free-range systems are the most challenging for lighting management because birds have access to natural daylight. The photoperiod is determined by the season, and you have limited control over light exposure.

In free-range systems, the goal is to provide supplemental light to maintain a minimum photoperiod of 14 hours. This means providing light in the early morning or late afternoon during the winter months. In the summer, you may need to restrict access to the outdoors to prevent excessive day length.

Organic Production

Organic standards may restrict certain lighting practices. Check with your certifying body for specific requirements. In general, organic producers can use supplemental lighting, but they must ensure that birds have access to the outdoors during daylight hours when weather permits.

The Relationship Between Light and Other Management Factors

Lighting does not work in isolation. The success of your lighting program depends on other management factors.

Nutrition

Hens need adequate nutrition to respond to light stimulation. A diet that is deficient in protein, calcium, or other nutrients will limit egg production regardless of the lighting program. Ensure that your feed meets the nutritional requirements of the breed and age of your flock.

Water

Water is essential for egg production. Hens will stop laying within a few days if water is unavailable. Check water lines and drinkers regularly to ensure that all birds have access to clean, fresh water.

Ventilation

Poor ventilation can cause respiratory problems and reduce feed intake, which will affect egg production. Ensure that your house has adequate ventilation for the number of birds and the weather conditions.

Stocking Density

Overcrowding causes stress and can reduce egg production. Follow the recommended stocking density for your production system and breed.

Health

Disease can cause rapid drops in egg production. Follow a vaccination program recommended by your veterinarian, and practice good biosecurity to prevent disease introduction.

Frequently Asked Questions

How many hours of light do laying hens need per day?

Laying hens need 14 to 16 hours of light per day to maintain maximum egg production. The photoperiod must be consistent and must never decrease during the laying period. A photoperiod of 15 hours is a good target for most flocks. Providing more than 16 hours of light does not increase production and can cause problems.

What is the best light intensity for laying hens?

The recommended light intensity is 10 to 30 lux at bird eye level. This is roughly equivalent to 1 to 3 foot-candles. Light levels below 5 lux are insufficient to stimulate egg production. Light levels above 30 lux do not increase production and can cause behavioral problems such as feather pecking.

Can I use LED bulbs for chicken coop lighting?

Yes, LED bulbs work well for poultry lighting. Choose bulbs with a warm white color temperature of 2700K to 3000K. LED bulbs are energy-efficient and last longer than incandescent bulbs. Ensure that the bulbs are dimmable if you plan to use a dimmer system, and check the light output with a light meter.

How long does it take for hens to start laying after light stimulation?

Hens typically start laying two to three weeks after the photoperiod is increased. It takes time for the hormonal changes to trigger ovulation. Peak production is usually reached four to six weeks after the first egg. Be patient and do not expect an immediate response to light changes.

Why did my hens stop laying after a power outage?

A power outage can disrupt the light schedule and cause a temporary drop in egg production. Hens are very sensitive to photoperiod changes. Restore the light schedule as soon as possible after a power outage. If the outage lasted more than a few hours, you may need to gradually adjust the schedule back to normal. Production should recover within a few days to a few weeks.

Should I provide light at night for my laying hens?

No, hens need a period of darkness for rest. Provide 8 to 10 hours of darkness per day. Continuous light causes stress and can lead to behavioral problems. The recommended photoperiod is 14 to 16 hours of light, which leaves 8 to 10 hours of darkness.

What color light is best for laying hens?

Warm white light with a color temperature of 2700K to 3000K is the safest choice. Some research suggests that blue or green light can have a calming effect and reduce feather pecking. Avoid red light because it can increase aggressive behavior and cannibalism.

Can I use natural sunlight instead of artificial light for my chicken coop?

Yes, natural sunlight can be part of your lighting program, especially in open-sided houses. However, the natural photoperiod varies with the season, and you will likely need supplemental light in the winter to maintain a minimum of 14 hours of light per day. In the summer, you may need to black out the house to prevent day length from exceeding 16 hours.

Related Farming Guides

This section will be populated with links to other farming guides on this site, covering topics such as pullet rearing, layer nutrition, egg quality management, and biosecurity for poultry flocks.

Related Clinical & Scientific Guides

• Poultry Farm Fencing: Materials, Design, and Predator Exclusion
• Broiler House Wind Speed and Airflow Measurement
• Broiler House Heating Systems: Types and Efficiency

References

• FAO Poultry Production: https://www.fao.org/poultry-production-products/en/
• USDA APHIS Poultry Health: https://www.aphis.usda.gov/livestock-poultry-disease/avian
• WOAH Avian Influenza: https://www.woah.org/en/disease/avian-influenza/
• FAO Animal Production and Health: https://www.fao.org/animal-production/en/
• WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/

This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.