# Farrowing House Lighting Programs for Sow Performance ## Key Takeaways - A target photoperiod of 16 hours of light and 8 hours of dark per day is recommended for lactating sows to optimize feed intake and milk production, mediated by the regulation of melatonin and prolactin secretion. - Light intensity should be maintained between 100 to 150 lux at sow eye level during the light period, with a dimmer 50 lux for the piglet creep area, to balance sow comfort and piglet safety while minimizing crushing. - Consistent daily photoperiod, achieved through a digital timer, is crucial for maintaining sow circadian rhythms and preventing behavioral disturbances like restlessness, which can increase piglet mortality. - Direct glare into sow eyes should be avoided by using shielded or indirect fixtures, as visual discomfort can lead to stress, reduced feed intake, and poor milk letdown. - Regular cleaning of light fixtures (at least monthly) is essential, as dust and manure film can reduce light output by 30-50%, negating the intended benefits of the lighting program. - Monitoring sow behavior (restlessness), feed intake, and piglet survival rates, alongside maintaining a lighting log, are critical for validating program effectiveness and identifying potential issues requiring veterinary consultation. --- Lighting in the farrowing house is often treated as an afterthought, something set once and forgotten until a bulb burns out. But light is a management tool with measurable effects on sow physiology, piglet survival, and labor efficiency. This guide explains how photoperiod, light intensity, and consistency influence sow performance in the farrowing barn. It is written for swine producers, herd managers, and farm employees who want a practical lighting program they can implement with standard equipment. You will learn how to set day length, choose fixtures, measure light levels, avoid common mistakes, and track whether your program is working. ## At a Glance - Target photoperiod for sows in the farrowing house: 16 hours of light and 8 hours of dark per day. Some operations use 14 hours of light with good results, but 16 hours is the more common recommendation. - Target light intensity at sow eye level: 100 to 150 lux during the light period. Piglets need lower intensity, around 50 lux, and they also need access to a darkened creep area. - Use a timer, not manual switching. Sows respond to a consistent day length, and manual routines drift over time. - Provide a distinct dark period. Continuous light disrupts melatonin patterns and can increase restless behavior. - Place lights to avoid direct glare into sow eyes. Indirect or shielded fixtures reduce stress. - Clean fixtures regularly. Dust and manure film can cut light output by 30 to 50 percent in a few weeks. - Measure light with a lux meter at sow eye level, not at the fixture or at human standing height. - Keep a lighting log. Record photoperiod settings, bulb changes, cleaning dates, and any farrowing performance changes you observe. - Call a veterinarian or extension agent if you see a pattern of restless sows, increased piglet crushing, or poor milk letdown that does not respond to lighting adjustments. ## Why Lighting Matters in the Farrowing House The farrowing house is a high stress environment for the sow. She is confined, giving birth, and nursing a large litter. Her endocrine system is coordinating a complex sequence of events from farrowing through lactation. Light is one of the environmental signals that drives this endocrine system. Sows are not seasonal breeders in the same way that sheep or horses are, but they still have a pineal gland that responds to light and dark cycles. The pineal gland produces melatonin during darkness and suppresses melatonin production during light. Melatonin influences the release of other hormones, including prolactin, which is critical for milk production. A consistent photoperiod helps keep this hormonal cascade on schedule. Research on sow photoperiod has focused on both gestation and lactation. Studies have shown that longer day length during lactation, in the range of 14 to 16 hours, is associated with increased feed intake in lactating sows. Higher feed intake supports better milk production and reduces the sow's body condition loss during lactation. Some trials have also reported improved piglet weight gain when sows are kept on a longer photoperiod. The dark period matters as much as the light period. Sows need a distinct night to maintain normal melatonin rhythms. Constant light can disrupt these rhythms and lead to behavioral problems. In continuous light, sows may show more restless activity, and restless sows are more likely to crush piglets when they lie down. Light intensity is a separate factor from photoperiod. Photoperiod is the length of the light period. Intensity is how bright the light is. A sow can be under a 16 hour photoperiod but still be in dim light that does not trigger the proper physiological response. The commonly cited target is 100 to 150 lux at the sow's eye level. For comparison, a well lit office is around 300 to 500 lux. A dim hallway might be 50 lux. Direct sunlight outdoors is 50,000 lux or more. The third factor is consistency. Sows are creatures of routine. If the lights come on at 6 a.m. some days and 8 a.m. other days, the sow's internal clock is confused. A timer set to the same schedule every day, including weekends and holidays, is essential. ## The Science Behind Photoperiod and Sow Performance The reproductive and lactational systems of the sow are regulated by a complex interplay of hormones. Light acts on this system through the retina, the suprachiasmatic nucleus in the brain, and the pineal gland. When light hits the retina, it sends a signal that suppresses melatonin production. When darkness falls, melatonin production rises. Melatonin is not just a sleep hormone. It modulates the secretion of gonadotropin-releasing hormone, which in turn affects luteinizing hormone and follicle stimulating hormone. These hormones control the estrous cycle and ovulation. During lactation, the sow is typically anestrous, meaning she is not cycling. The suckling stimulus from piglets suppresses gonadotropin release. Light can influence how quickly the sow returns to estrus after weaning. Prolactin is another key hormone. It is essential for mammary development and milk synthesis. Prolactin secretion is influenced by the suckling stimulus and by melatonin. A consistent photoperiod during lactation helps maintain adequate prolactin levels, which supports milk production. Several studies have examined the effect of photoperiod on lactating sows. One line of research compared sows kept on 16 hours of light per day with sows kept on 8 hours. The sows on the longer photoperiod consumed more feed during lactation. This is a meaningful finding because feed intake during lactation is often a limiting factor. Sows that eat more produce more milk and lose less body condition. Another study looked at piglet performance. Litters from sows on a longer photoperiod had slightly higher average daily gains. The effect was modest but consistent across the trial. The mechanism is likely through increased milk production from better fed sows. The dark period is not just an absence of light. It is an active part of the program. During darkness, melatonin levels rise. This melatonin surge helps regulate the sow's circadian rhythms. When the light period is continuous, or when the dark period is frequently interrupted, melatonin rhythms flatten. Flattened rhythms are associated with increased stress and altered behavior. In practical terms, a sow on continuous light may show more pacing and standing behavior. Standing is dangerous in a farrowing crate because it increases the chance of the sow stepping on or lying on a piglet. A sow that is calm and lying quietly is safer for her litter. Light intensity also affects the sow's response. A very dim light, below 50 lux, may not fully suppress melatonin production even during the light period. The pineal gland needs a certain threshold of light to stop melatonin output. That threshold is somewhere around 50 to 100 lux for pigs. Below that, the sow may be in a twilight state where her melatonin levels are partially suppressed. This can blunt the benefits of a long photoperiod. ## Setting Up Your Farrowing House Lighting Program Implementing a lighting program requires attention to four components: photoperiod, intensity, uniformity, and consistency. Each component is adjustable with standard farm equipment. ### Step 1: Choose Your Photoperiod Set your timer for 16 hours of light and 8 hours of dark. This is the most common recommendation from swine specialists and the setting used in most research trials. If you are concerned about energy costs, you can use 14 hours of light and 10 hours of dark. The difference in sow response between 14 and 16 hours is small, but 16 hours is the safer target. Choose the start time based on your labor schedule. Many farms set lights to come on at 6 a.m. and turn off at 10 p.m. This gives staff light for morning chores and evening checks. The exact times matter less than the consistency. Pick a schedule and stick to it. Do not use a photocell or light sensor for the primary timer. Photocells respond to cloud cover and seasonal changes, which creates variable day length. A simple mechanical or digital timer is better. Digital timers are more accurate and easier to adjust for daylight saving time changes. ### Step 2: Select the Right Fixtures The type of light fixture matters for both intensity and uniformity. LED fixtures are the current standard for new installations. They are energy efficient, have a long service life, and produce a clean white light. Fluorescent fixtures are still common in older barns and work adequately if they are clean and not near the end of their service life. Incandescent bulbs are inefficient and produce more heat than light, which is a disadvantage in a warm farrowing house. For a typical farrowing crate, you need a fixture that provides 100 to 150 lux at the sow's eye level. Sow eye level is roughly 24 to 30 inches above the floor when she is standing or lying with her head up. A single 15 to 20 watt LED tube or a 100 watt equivalent LED bulb mounted directly above the crate can provide this level. Consider the color temperature of the light. Color temperature is measured in Kelvin. A warm white light around 2700 to 3000 K is similar to an incandescent bulb. A cool white or daylight light around 4000 to 5000 K is brighter and more like natural daylight. For farrowing houses, a neutral white around 4000 K is a good choice. It makes it easier to see piglets and detect health problems, and it provides adequate light for the sow. Mount fixtures so they are protected from moisture and dust. Farrowing houses are humid environments with ammonia in the air. Use fixtures with a sealed lens or a high ingress protection rating. This prevents corrosion and reduces the need for frequent replacement. ### Step 3: Position Lights to Avoid Glare Direct glare into the sow's eyes is stressful. A sow that is squinting or turning her head away from the light is not resting properly. Position fixtures so they are above and slightly in front of the sow, not directly in her line of sight. If you use individual crate lights, mount them toward the front of the crate, over the sow's feed trough area. This lights the area where the sow is most active and keeps the creep area at the back of the crate darker for the piglets. Shielded fixtures or fixtures with a diffuser reduce glare. A simple metal shield or a strip of aluminum foil can redirect light away from the sow's eyes. Some producers use indirect lighting, where the light bounces off the ceiling or a wall before reaching the sow. This produces a softer, more uniform light but requires more fixtures to achieve the same intensity. ### Step 4: Provide a Dark Creep Area for Piglets Piglets do not need bright light. In fact, bright light can be stressful for them. The creep area at the back of the crate should be darker than the rest of the crate. This encourages piglets to stay in the creep, away from the sow, which reduces the risk of crushing. A heat lamp in the creep area provides both warmth and light. The heat lamp creates a localized bright spot, but the surrounding creep area can remain dim. If your farrowing house has general overhead lighting that is very bright, consider using a shade or a partial cover over the creep area to create a darker zone. Piglets have a natural preference for warmth. If the creep area is warm and dim, they will choose it over the bright, open area near the sow. This is one of the simplest and most effective ways to reduce piglet mortality. ### Step 5: Set Up a Timer and Stick to It Install a timer for the main farrowing house lights. The timer should control the general overhead lights, not the heat lamps in the creep areas. Heat lamps should run continuously or be controlled by a separate thermostat. Use a digital timer with a battery backup. If the power goes out, the timer will remember its settings. A mechanical timer can drift over time, especially if it is subject to vibration or temperature changes. Check the timer at least once a month to confirm it is on schedule. If you have multiple rooms in your farrowing house, you may want separate timers for each room. This allows you to stagger the light cycles if you are working in one room while sows in another room are in their dark period. However, for simplicity, most farms run all rooms on the same schedule. ### Step 6: Measure Light Intensity Do not guess at light levels. Use a lux meter to measure the actual intensity at sow eye level. A handheld lux meter costs between 20 and 50 dollars and is a worthwhile investment. To measure, hold the lux meter at the height of the sow's head, about 24 to 30 inches above the floor. Take readings at several points in the crate: at the front near the feed trough, in the middle, and at the back near the creep area. The readings at the front and middle should be 100 to 150 lux. The reading at the back can be lower, around 50 lux, to create the darker creep zone. Measure at the time of day when the lights are on their standard cycle. Do not measure on a sunny day when sunlight is streaming through windows or vents, as this will give a false high reading. Measure on an overcast day or in the evening when the artificial lights are the only source. If your readings are below 100 lux, you need more light. This could mean adding fixtures, cleaning existing fixtures, or replacing bulbs with higher output models. If your readings are above 150 lux, you may want to reduce intensity or reposition fixtures to reduce glare. ### Step 7: Establish a Cleaning Schedule Dust and manure film accumulate on light fixtures quickly in a farrowing house. A thin layer of dust can reduce light output by 20 percent. A heavier film can cut output by 50 percent or more. This means your 150 lux reading at installation could drop to 75 lux within a month if you do not clean. Clean fixtures at least monthly. Use a damp cloth or a mild detergent solution. Do not spray water directly into the fixture or the electrical connections. Turn off the power to the fixture before cleaning to avoid shock or damage. In addition to cleaning fixtures, check for dead or flickering bulbs. Replace them promptly. A single dead bulb in a row of fixtures creates a dark spot that can be significant at crate level. ## Common Mistakes in Farrowing House Lighting ### Mistake 1: Leaving Lights On 24 Hours a Day Continuous light is a common error, especially in farms where staff want to see into the crates at any time of day. Continuous light disrupts the sow's melatonin rhythm. Over time, this can lead to increased restlessness, reduced feed intake, and poorer milk production. The solution is to commit to a dark period. If staff need to check sows at night, use a dim flashlight or install a low wattage blue light that is less disruptive to the sow's circadian rhythm. Red light is also an option. Red light does not suppress melatonin as strongly as white light. ### Mistake 2: Using a Photocell Instead of a Timer Photocells are designed to turn lights on when it gets dark and off when it gets light. This creates a variable photoperiod that follows the seasons. In summer, the lights may be on for only 8 hours. In winter, they may be on for 14 hours. This variability is not what you want for sows. Use a timer set to a fixed schedule. If you want to save energy, you can use a photocell in combination with a timer, where the timer limits the maximum light period and the photocell adjusts for dawn and dusk. But for most farms, a simple timer is sufficient. ### Mistake 3: Measuring Light at the Wrong Height Light intensity decreases with distance from the source. If you measure light at human standing height, you will get a reading that is higher than what the sow experiences. The sow's head is much closer to the floor. Always measure at sow eye level. If you are not sure where that is, kneel down and look at the crate from the sow's perspective. The light that reaches the sow's eyes is what matters. ### Mistake 4: Ignoring the Creep Area A bright farrowing house with no dark creep zone is a recipe for piglet crushing. Piglets that cannot find a dark, warm place to sleep will lie near the sow. When the sow lies down, she may crush them. Create a distinct creep area with a heat lamp and some form of visual barrier. A solid panel or a curtain at the back of the crate helps block light and creates a cave-like environment that piglets prefer. ### Mistake 5: Neglecting Fixture Maintenance Dirty fixtures, dead bulbs, and corroded connections are common in farrowing houses. These problems reduce light output gradually, so you may not notice the decline until it is severe. Build lighting maintenance into your weekly or monthly checklist. Walk the farrowing house with a lux meter and check every crate. Clean fixtures on a schedule, not when you remember to do it. ### Mistake 6: Making Sudden Changes to the Photoperiod Sows adapt to a photoperiod over several days. If you suddenly change from 12 hours of light to 16 hours, the sow's system needs time to adjust. During this adjustment period, you may see a temporary dip in feed intake or an increase in restlessness. Make changes gradually. If you are transitioning from an unmanaged lighting situation to a structured program, increase the light period by 30 minutes every 2 to 3 days until you reach your target. This gradual transition is less stressful for the sows. ## Decision Thresholds and Troubleshooting A lighting program is not a set and forget system. You need to monitor sow behavior and performance to confirm the program is working. Here are some thresholds to watch for. ### Feed Intake Lactating sows should eat readily when feed is offered. If you see a pattern of sows leaving feed in the trough, or if sows are slow to come to the feeder when feed is delivered, check your lighting. A sow that is stressed by glare or confused by an inconsistent photoperiod may eat less. A sow on a 16 hour photoperiod should consume more feed than a sow on a shorter photoperiod. If you track feed intake by crate or by room, compare your current intake to your historical baseline. A drop of more than 10 percent over several days warrants investigation. ### Sow Restlessness Restlessness is a behavioral sign that something is wrong. A restless sow stands frequently, paces in the crate, or shifts position often. This is dangerous for piglets. If you see an increase in piglet crushing, restlessness is likely a contributing factor. Check your lighting if you see restlessness. Is the light too bright and causing glare? Is the dark period too short or frequently interrupted? Is the timer working correctly? ### Piglet Survival Piglet survival is the ultimate measure of farrowing house management. If your preweaning mortality is above 12 to 15 percent, look at all environmental factors, including lighting. Lighting alone may not be the cause, but it can be a contributing factor if it leads to sow restlessness or poor milk production. Track piglet mortality by cause. If crushing is the [dominant](/blog/careers/dominant-definition-biology) cause, lighting is a suspect. If starvation or scours is the dominant cause, milk production is more likely the issue, and lighting can influence milk production through its effect on sow feed intake. ### Milk Letdown Milk letdown is controlled by oxytocin release. A stressed sow may have poor milk letdown, which means piglets do not get enough milk even though the sow is producing it. Signs of poor letdown include piglets constantly at the udder, squealing, and fighting, and sows that seem agitated when piglets nurse. Lighting stress can contribute to poor letdown. Check for glare, excessive brightness, or an inconsistent photoperiod. Give the sow a quiet, dim environment during the nursing period. ### When to Call a Veterinarian or Extension Agent Lighting adjustments can solve many environmental problems, but they are not a cure for disease or a substitute for veterinary care. Call a veterinarian if you see: - A sudden drop in feed intake across multiple sows - A spike in sow body temperature or signs of illness - An increase in stillborn piglets or a high rate of piglet mortality - Sows that are off feed for more than 24 hours after farrowing - Signs of mastitis, metritis, or agalactia Call an extension agent or a swine specialist if you have implemented a lighting program and do not see the expected improvements in feed intake or piglet performance. They can help you evaluate your setup and make adjustments. ## Monitoring and Recordkeeping A lighting program is only as good as your ability to track it. Keep a simple log for each farrowing room. Record the following: - Date and time of any photoperiod changes - Timer settings and any adjustments - Bulb replacements and fixture cleaning dates - Lux meter readings at sow eye level, taken monthly - Any behavioral observations, such as restlessness or changes in nursing behavior - Feed intake by room or by individual sow - Piglet mortality and causes Review this log monthly. Look for patterns. Did piglet mortality go up in the weeks after you changed the timer? Did feed intake improve after you cleaned the fixtures? These correlations help you fine tune your program. Some farms use electronic monitoring systems that track feed intake and sow activity automatically. If you have such a system, use it to validate your lighting program. If you do not have electronic monitoring, a paper log kept by the herd manager is sufficient. ### Sample Lighting Log | Date | Room | Timer On | Timer Off | Lux Reading | Bulbs Changed | Fixtures Cleaned | Notes | |------|------|----------|-----------|-------------|---------------|------------------|-------| | 1/15 | 1 | 6:00 AM | 10:00 PM | 120 | No | Yes | Sows calm | | 1/15 | 2 | 6:00 AM | 10:00 PM | 95 | No | No | Below target, clean next week | | 2/1 | 1 | 6:00 AM | 10:00 PM | 135 | 2 | Yes | Feed intake up 5% | ## Energy Considerations and Cost A lighting program does not have to be expensive to run. LED fixtures use significantly less energy than incandescent or fluorescent fixtures. A 20 watt LED fixture running 16 hours per day uses about 0.32 kilowatt hours per day. At an electricity rate of 15 cents per kilowatt hour, that is about 5 cents per day per fixture. For a 20 crate farrowing house with 20 fixtures, that is about 1 dollar per day in lighting energy. Compare this to the value of improved piglet survival and sow performance. A single extra piglet weaned per litter can be worth 30 to 50 dollars depending on market prices. If a lighting program helps you save even one piglet per litter across 20 litters, the return is substantial. Energy saving strategies include: - Use LED fixtures with a high lumens per watt rating - Install occupancy sensors in hallways and non production areas so lights are only on when someone is present - Use timers to ensure lights are off during the dark period - Keep fixtures clean to maximize output without adding fixtures - Consider dimming controls if you have variable tasks that need different light levels ## Special Considerations for Different Farrowing Systems ### Conventional Farrowing Crates In a conventional crate system, each sow is in an individual crate with a piglet creep area. Lighting is usually provided by overhead fixtures in the room. This system is the most straightforward to manage. Set the room timer, measure at crate level, and adjust as needed. ### Group Farrowing Systems Group farrowing systems, where sows are housed in pens with more freedom, present different lighting challenges. The sow can move around, so light levels vary more across the pen. You need to provide adequate light across the entire pen, not just at a single crate. In group systems, the creep area is often a separate zone that piglets can access but sows cannot. This area should be dim and warm. The sow feeding area should be well lit. The lying area can be moderate. ### Outdoor or Hoop Barns Outdoor and hoop barns rely on natural light, which varies by season and weather. Artificial lighting is supplemental. In these systems, the photoperiod is not fully controlled. You can extend the day length with artificial light, but you cannot shorten it if the natural day is long. For outdoor systems, focus on providing consistent supplemental light during the dark hours of the day. Use a timer to turn on lights in the evening and off in the morning. This gives sows a predictable light period even when natural light is variable. ### Farrowing Houses with Windows Windows can be a source of natural light, but they also create variability. On a sunny day, light levels may be very high. On a cloudy day, they may be low. Windows can also create glare and drafts. If your farrowing house has windows, consider covering them or using translucent panels that diffuse light. This reduces variability and glare. If you want to use natural light to supplement your lighting program, orient the windows to avoid direct sun on the sows. ## The Role of Light Color Light color, or wavelength, affects how the sow perceives her environment. Pigs are dichromatic, meaning they have two types of color receptors in their eyes. They see blues and greens well but have limited sensitivity to reds. This has practical implications. A red light used for nighttime observation is less visible to the sow than to humans. It is also less disruptive to her melatonin production. If you need to check sows at night, a red light is a good choice. Blue light is more visible to pigs and can be more stimulating. Some research suggests that blue light may have different effects on melatonin suppression than other wavelengths. For general farrowing house lighting, a neutral white light around 4000 K is a safe choice. ## Timing of Lighting Changes Around Farrowing The transition from gestation to lactation is a critical period. Some producers wonder whether they should change the photoperiod when sows enter the farrowing house. The answer is to maintain consistency. If your gestation barn runs on a 12 hour photoperiod and your farrowing house runs on 16 hours, sows will experience a sudden change when they move. This can be stressful. Ideally, you should transition sows to the farrowing house photoperiod a few days before they move. If that is not possible, accept that there will be a short adjustment period. Some research has explored whether a shorter photoperiod around farrowing is beneficial. The theory is that a shorter day length might reduce stress during the farrowing process. However, the evidence for this is not strong. Most swine specialists recommend maintaining a consistent 16 hour photoperiod throughout lactation. ## Lighting and Sow Comfort Sow comfort is not just about temperature and floor type. Light affects comfort through its influence on behavior. A sow that is comfortable will lie quietly, rest, and nurse her piglets in a relaxed manner. A sow that is uncomfortable will be restless and alert. Bright, glaring light can make a sow feel exposed and vulnerable. In the wild, pigs are prey animals. They prefer to rest in areas with cover and shade. A farrowing crate is already a stressful environment because the sow cannot escape. Adding bright, harsh light increases that stress. Use diffusers, shields, and indirect lighting to create a softer light environment. The goal is to provide enough light for the sow to see clearly and for staff to work safely, but not so much that the sow feels exposed. ## Lighting for Staff Safety and Performance While the sow's needs are the primary focus, lighting also affects the people who work in the farrowing house. Staff need adequate light to perform tasks safely and accurately. This includes checking piglets, assisting with difficult farrowings, and cleaning crates. The 100 to 150 lux target at sow eye level is generally adequate for these tasks. However, staff may need higher light levels for detailed work such as giving injections or performing castrations. Portable task lights or headlamps can provide additional light for these procedures without increasing the general light level. Good lighting also reduces the risk of accidents. Trips, falls, and equipment mishaps are more common in dimly lit areas. Ensure that walkways and alleyways are well lit, even if the crates themselves are at a lower light level. ## Developing a Lighting Standard Operating Procedure A written standard operating procedure for farrowing house lighting helps ensure consistency, even when staff changes. Your SOP should include: - The target photoperiod (16 hours light, 8 hours dark) - The target light intensity (100 to 150 lux at sow eye level) - The timer schedule and how to adjust it - The cleaning schedule for fixtures - The procedure for measuring light with a lux meter - The log to be maintained and who is responsible for it - The procedure for reporting and correcting lighting problems Post the SOP in the farrowing house or in the farm office. Review it at least annually and update it if you change equipment or procedures. ## Integrating Lighting with Other Farrowing House Management Lighting does not work in isolation. It interacts with temperature, ventilation, nutrition, and health. A lighting program is most effective when it is part of a comprehensive farrowing house management plan. ### Temperature Sows prefer a cooler environment than piglets. The farrowing house temperature is usually set around 70 to 75 degrees Fahrenheit for the sow, with a creep area at 90 to 95 degrees for the piglets. Lighting can affect temperature. Incandescent bulbs produce significant heat, which can raise the temperature in the crate. LED bulbs produce much less heat, which is an advantage in the summer but means you may need to supplement heat in the creep area. If you switch from incandescent to LED lighting, monitor the temperature in the farrowing house. You may need to adjust the ventilation or add supplemental heat in the creep area. ### Ventilation Ventilation removes moisture, ammonia, and odors from the farrowing house. It also removes heat. Lighting fixtures can interfere with airflow if they are mounted in a way that blocks vents or creates pockets of stagnant air. When installing new fixtures, consider the airflow pattern. Mount fixtures so they do not obstruct air inlets or exhaust fans. Keep fixtures away from direct moisture sources, such as water lines or nipple drinkers. ### Nutrition Lighting influences feed intake, which in turn influences nutritional status. A sow that eats more during lactation produces more milk and loses less body condition. This has long term effects on her subsequent reproductive performance. Work with your nutritionist to ensure the lactation diet meets the sow's needs. If your lighting program increases feed intake, the sow may need a diet with higher energy density or different amino acid levels. Monitor body condition and adjust feeding levels accordingly. ### Health A well lit farrowing house makes it easier to spot health problems early. Staff can see piglets that are scouring, sows that are off feed, or signs of mastitis. Good lighting is a tool for disease surveillance. Conversely, poor lighting can hide problems until they are advanced. A piglet that is weak and failing to nurse may be overlooked in a dim crate. Regular observation under good lighting is essential for early intervention. ## Frequently Asked Questions ### How many hours of light do sows need in the farrowing house? Sows in the farrowing house should receive 16 hours of light and 8 hours of dark each day. Some operations use 14 hours of light with acceptable results, but 16 hours is the more common recommendation based on research showing improved feed intake and piglet growth. The key is consistency. Use a timer to maintain the same schedule every day. ### What is the ideal light intensity for a farrowing house? The target light intensity is 100 to 150 lux at the sow's eye level, which is about 24 to 30 inches above the floor. Piglets need less light, around 50 lux, and benefit from a darker creep area. Measure with a lux meter to confirm your fixtures are providing adequate light. ### Can too much light hurt sows or piglets? Yes. Continuous light, meaning 24 hours per day, disrupts the sow's melatonin rhythm and can lead to restlessness and reduced feed intake. Very bright light, above 200 lux, can cause glare and stress. Piglets prefer a dimmer environment and need a dark creep area to feel secure. The goal is a distinct light period and a distinct dark period, not maximum brightness. ### Should I use red light for nighttime checks in the farrowing house? Red light is a good choice for nighttime checks because pigs have limited sensitivity to red wavelengths. It is less disruptive to the sow's melatonin production than white or blue light. Use a dim red light or a red headlamp for nighttime observations. Avoid turning on the main white lights during the dark period. ### How often should I clean my farrowing house light fixtures? Clean light fixtures at least once a month. Dust and manure film can reduce light output by 30 to 50 percent in a few weeks. In a dusty or humid environment, you may need to clean more frequently. Turn off the power before cleaning and use a damp cloth or mild detergent. ### Do LED lights work well in a farrowing house? LED lights work very well in farrowing houses. They are energy efficient, produce less heat than incandescent bulbs, and have a long service life. Choose a sealed fixture with a high ingress protection rating to withstand the humid, corrosive environment. A neutral white light around 4000 K is a good choice. ### How long does it take for sows to adjust to a new lighting schedule? Sows typically adjust to a new photoperiod over 3 to 7 days. During this adjustment period, you may see a temporary dip in feed intake or an increase in restlessness. To minimize stress, change the photoperiod gradually, by 30 minutes every 2 to 3 days, rather than making a sudden change. ### What should I do if my sows are still restless after I fix the lighting? If sows remain restless after you have corrected the photoperiod, intensity, and glare, look for other causes. Check the temperature, ventilation, and floor condition. Review the sow's health and comfort. If the problem persists, call your veterinarian or a swine extension specialist for a full evaluation of the farrowing environment. ## Related Farming Guides This section will be populated with links to related farming guides on sow management, farrowing house design, piglet care, and swine health. Check back for updated resources on optimizing your farrowing operation. ## Related Clinical & Scientific Guides * [Pig Enrichment Programs and Behavior Monitoring](/knowledge/animal-farming/swine/pig-enrichment-programs-and-behavior-monitoring) * [Swine Handling Facility Design for Safe Pig Movement](/knowledge/animal-farming/swine/swine-handling-facility-design-safe-pig-movement) * [Swine Feeding Management for Grow-Finish Pigs](/knowledge/animal-farming/swine/swine-feeding-management-for-grow-finish-pigs) ## References - National Pork Board: https://www.pork.org/ - USDA APHIS Swine Health: https://www.aphis.usda.gov/livestock-poultry-disease/swine - FAO Pig Production: https://www.fao.org/pig-production-and-products/en/ - 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.