# Nursery Pig Lighting Programs for Growth and Welfare ## Key Takeaways - For the initial 7-10 days post-weaning, a photoperiod of 18-24 hours of light per day is critical to stimulate feed and water intake, mitigating post-weaning anorexia. Following this adaptation phase, a photoperiod of 12-16 hours of light and 8-12 hours of dark supports balanced growth and rest, facilitating normal melatonin cycles. - Light intensity should be maintained between 100-150 lux at pig eye level in general nursery areas, with higher intensities (≥200 lux) recommended for inspection zones to facilitate accurate visual assessment of pig health and condition. - LED or fluorescent fixtures with a color temperature of 4000K-5000K (cool white) are recommended for optimal visibility and color discrimination, while dimmers or timers should be employed to create gradual dawn/dusk transitions, minimizing startle responses and associated behavioral disturbances. - Regular cleaning of light fixtures every 4-6 weeks is essential, as accumulated dust and grime can reduce light output by 30-50%, significantly impacting light intensity and uniformity within pens. - A minimum of 6 hours of uninterrupted darkness daily is crucial for supporting normal circadian rhythms, melatonin production, and adequate sleep, which are vital for immune function and overall physiological well-being in nursery pigs. --- Lighting is one of the most overlooked management tools in modern swine production. Nursery barn lighting programs directly influence feed intake, weight gain, immune function, and behavior in weaned pigs. This article explains how light intensity, photoperiod, and light source affect nursery pig performance and welfare. It provides step-by-step guidance for designing a lighting program, troubleshooting common problems, and monitoring results. The intended readers are swine farm owners, herd managers, and stockpeople who want practical, research-backed answers they can apply in their own nursery barns. ## At a Glance - Provide 18 to 24 hours of light per day for the first 7 to 10 days after weaning to encourage feed and water intake. - After the initial adaptation period, use a 12 to 16 hour light to 8 to 12 hour dark photoperiod to balance growth and rest. - Target light intensity at pig eye level between 100 and 150 lux for general nursery areas and 200 lux or more for inspection areas. - Use LED or fluorescent fixtures with a color temperature between 4000K and 5000K for even, cool-white light. - Install dimmers or timers to create gradual dawn and dusk transitions that reduce startle responses. - Clean light fixtures every 4 to 6 weeks because dust and grime can cut light output by 30 to 50 percent. - Measure actual light levels with a lux meter rather than relying on fixture ratings or visual assessment. - Provide a minimum 6 hour uninterrupted dark period each day to support normal melatonin cycles and sleep behavior. - Check lighting circuits and fixtures at every barn walkthrough and log any failures or intensity drops. ## Why Nursery Pig Lighting Matters Weaned pigs face a sudden set of stressors. They leave the sow, encounter new penmates, learn to use new feeders and drinkers, and cope with a different environment. During this transition, the nursery barn must support rapid adaptation. Lighting is a central part of that support system, yet it is often treated as an afterthought. Light affects pigs through two main pathways. The first is vision. Pigs use sight to locate feed, water, and penmates. A dim or unevenly lit barn makes it harder for newly weaned pigs to find the feeder and drinker, especially in the first days after placement. The second pathway is the circadian system. Light signals travel from the eye to the suprachiasmatic nucleus in the brain, setting the daily rhythm of hormones such as melatonin and cortisol. These hormones influence sleep, stress responses, metabolism, and immune function. When nursery barn lighting is poorly managed, pigs may eat less, rest less, and show more aggressive or fearful behavior. When lighting is managed well, pigs adapt faster, grow more consistently, and are easier for staff to inspect. This article walks through each element of a nursery pig lighting program so you can make deliberate choices rather than relying on whatever fixtures happen to be in the barn. ## Understanding Photoperiod for Nursery Pigs Photoperiod is the daily cycle of light and dark. It is the most studied aspect of lighting for growing pigs. The key question for nursery managers is how many hours of light per day produce the best growth and welfare outcomes. ### The Case for Longer Photoperiods Research on weaned pigs has consistently shown that longer photoperiods improve average daily gain and feed intake during the nursery phase. Pigs given 18 to 24 hours of light per day tend to visit the feeder more often and consume more total feed than pigs on shorter photoperiods. The effect is strongest in the first week after weaning when feed intake typically drops to near zero for many pigs. Several mechanisms explain this response. More light hours mean more opportunities for pigs to find and approach the feeder. Newly weaned pigs have to learn that feed is available in a new location. A bright, continuously lit barn removes the visual barrier of darkness during the critical learning window. Additionally, light stimulates activity. Pigs on long photoperiods are more active overall, which translates to more feeding events spread across the day. ### The Need for Dark Periods Long photoperiods are not without tradeoffs. Pigs need sleep for proper growth and immune function. Melatonin, the hormone that regulates sleep, is produced during darkness. Without a dark period, melatonin rhythms flatten and pigs may show altered sleep patterns. Some studies also suggest that continuous light increases circulating cortisol, a stress hormone, which can suppress immune function over time. The practical compromise used by many swine operations is a phased photoperiod. For the first 7 to 10 days after weaning, provide 20 to 24 hours of light. This maximizes feed intake during the highest-risk period. After that adaptation phase, step the photoperiod down to 12 to 16 hours of light and 8 to 12 hours of dark. This gives pigs the growth benefits of longer light exposure while preserving a normal daily rhythm. ### Matching Photoperiod to Barn Conditions Your specific barn conditions should influence your photoperiod choice. Barns with poor ventilation may benefit from shorter photoperiods because more light hours mean more pig activity and more heat production. In hot weather, consider using the minimum effective photoperiod to reduce activity during the hottest part of the day. In cold weather, longer photoperiods can encourage activity that helps pigs stay warm, though bedding and heating systems should be the primary tools for temperature control. If your nursery barn has windows or natural light infiltration, account for that when setting your artificial lighting schedule. A completely dark period may be impossible in a barn with large windows. In that case, aim for a dim period rather than total darkness and use blackout curtains if you need a true dark phase for research or special management protocols. ## Light Intensity for Nursery Barns Light intensity, measured in lux, describes how much light falls on a surface. For nursery pigs, the relevant surface is the floor at pig eye level. A newly weaned pig has its eyes roughly 20 to 30 centimeters above the floor, so measuring at that height matters more than measuring at human eye level. ### Recommended Intensity Levels Most swine extension guidance recommends a minimum of 80 to 100 lux in nursery pig areas during the light phase. Many commercial operations target 100 to 150 lux to ensure even coverage across the pen. For inspection areas, such as aisles and sorting pens, aim for 200 lux or more so stockpeople can see pig condition clearly. To put these numbers in context, a typical overcast day outdoors provides around 1000 lux. A well-lit office is about 300 to 500 lux. A dim hallway might be 50 lux. Nursery barns often fall into the 50 to 150 lux range depending on fixture age, cleanliness, and spacing. If your barn is on the low end, pigs may struggle to see feed and penmates clearly. ### Measuring Light Intensity Do not trust your eyes when assessing barn lighting. Human eyes adapt to dim conditions, making a poorly lit barn look brighter than it is. Use a handheld lux meter to measure actual light levels. Take readings at multiple points across each pen, including corners and areas near the walls. Log the readings by pen and fixture so you can identify weak zones. Measure light intensity at pig eye level, not at the ceiling or at human head height. Hold the meter sensor at about 25 centimeters above the floor and point it upward. Take readings at least 3 to 5 locations per pen. Do this at the same time of day on a consistent schedule, such as weekly or after any fixture changes. ### Achieving Even Light Distribution Uneven lighting creates shadows and dark corners where pigs may hesitate to explore. Feeder areas and drinker areas need to be well lit so pigs can see the equipment. Aim for a uniformity ratio of no more than 3 to 1 between the brightest and dimmest areas of a pen. If one corner is 150 lux and another is 30 lux, pigs in the dark corner are at a disadvantage. To improve uniformity, space fixtures closer together or use fixtures with wider beam angles. Reflective surfaces, such as white walls and ceilings, help bounce light into shadowed areas. Keep reflective surfaces clean. A coat of dust on walls and ceilings can absorb a surprising amount of light. ## Light Source Options for Nursery Barns The type of light fixture you choose affects energy use, light quality, and maintenance requirements. The three main options are incandescent, fluorescent, and LED. ### Incandescent Bulbs Incandescent bulbs are the traditional option but are now rarely used in new nursery barn construction. They are inefficient, convert most energy to heat rather than light, and have short lifespans. The warm color of incandescent light is not ideal for pig vision. If your barn still uses incandescent bulbs, plan to replace them with LED or fluorescent fixtures as part of your maintenance cycle. ### Fluorescent Tubes Fluorescent lighting has been the standard in swine barns for decades. It is more efficient than incandescent and provides even, diffuse light when properly installed. Fluorescent tubes come in different color temperatures. For nursery barns, choose tubes in the 4000K to 5000K range. These provide a neutral to cool white light that supports good color discrimination and visibility. The main drawbacks of fluorescent lighting are cold sensitivity and ballast failure. In cold nursery barns, standard fluorescent tubes may flicker or fail to start. Use cold-rated ballasts and tubes designed for low temperatures if your barn runs below 50 degrees Fahrenheit. Fluorescent tubes also contain small amounts of mercury, so they require careful disposal. ### LED Fixtures LED lighting is the current best choice for new installations and major retrofits. LEDs are highly efficient, have long rated lifespans of 50,000 hours or more, and tolerate cold temperatures well. They start instantly even in freezing conditions, which is a major advantage in winter nursery barns. LED fixtures come in a range of color temperatures. Choose 4000K to 5000K for nursery areas. This range provides bright, clean light that makes pigs and pen conditions easy to see. Some LED fixtures are dimmable, which allows you to create gradual dawn and dusk transitions. Dimmable LEDs require compatible dimmers and drivers, so check specifications before purchasing. ### Comparing Total Costs When comparing light sources, look at total cost of ownership rather than purchase price alone. LEDs cost more upfront than fluorescents but use less electricity and last longer. A typical LED fixture may last 5 to 10 times longer than a fluorescent tube, reducing replacement labor and material costs. Over a 10 year barn life, LEDs are usually the lower cost option despite the higher initial investment. ## Designing a Nursery Barn Lighting Program A complete lighting program has four components: photoperiod schedule, intensity targets, fixture placement, and maintenance. Each component needs a written plan that staff can follow consistently. ### Step 1: Set Your Photoperiod Schedule Decide on your light and dark hours and write them down. Post the schedule near the barn controller or in the employee break area. A typical nursery schedule looks like this: - Days 0 to 7 after weaning: lights on 24 hours per day. Some operations use 20 hours on and 4 hours off to give pigs a short rest period. - Days 8 to 14 after weaning: lights on 16 hours and off 8 hours. Provide the dark period during the coolest part of the day or overnight, whichever matches your ventilation schedule. - Days 15 to end of nursery: lights on 12 to 14 hours and off 10 to 12 hours. Match the light phase to staff working hours so inspections happen during full light. Use an automatic timer to control the schedule. Manual switching leads to inconsistent photoperiods, especially when staff are busy or shifts change. Digital timers with battery backup are inexpensive and reliable. If your barn controller supports lighting schedules, program the photoperiod there and set an alarm for any controller failures. ### Step 2: Choose Your Intensity Targets Set intensity targets for each area of the nursery. A simple target table might look like this: | Area | Target Intensity | |---|---| | General pen area | 100 to 150 lux | | Feeder and drinker zones | 150 to 200 lux | | Inspection aisle | 200 lux minimum | | Sorting or treatment area | 200 to 300 lux | Write these targets into your standard operating procedures. Include the measurement method and frequency so all staff follow the same protocol. ### Step 3: Lay Out Fixtures for Even Coverage The number and spacing of fixtures depends on the barn dimensions, ceiling height, and fixture beam angle. As a starting point, space fixtures no more than 1.5 times the mounting height apart. For a barn with 8 foot ceilings, space fixtures roughly 10 to 12 feet apart. For 10 foot ceilings, space them 12 to 15 feet apart. Position fixtures so they illuminate feeder and drinker areas directly. Pigs need to see these critical resources clearly. Avoid placing fixtures directly over the resting area if that creates glare or heat. Use reflectors or diffusers to spread light evenly and reduce harsh shadows. ### Step 4: Install Dimmers and Timers Gradual light transitions reduce stress in pigs. A sudden bright light after a dark period can startle pigs and cause a burst of activity that leads to fighting or pile-ups. A sudden dark period can cause panic in pigs that are still active and away from their resting area. Install dimmers that can ramp light up or down over 15 to 30 minutes. Many LED drivers support this function. If dimmers are not feasible, use timers that switch lights in stages. For example, turn on every third fixture first, then the rest 10 minutes later. This creates a rough dawn effect. ### Step 5: Create a Maintenance Schedule Light output declines over time as bulbs age and dust accumulates. A maintenance schedule prevents gradual light loss from going unnoticed. Include these tasks: - Clean fixtures every 4 to 6 weeks with a dry cloth or gentle vacuum. Do not use water near electrical components. - Replace failed bulbs or tubes immediately. A single failed fixture can create a dark spot that affects multiple pens. - Check timers and dimmers monthly to confirm they are set correctly. - Measure light intensity monthly and log the readings. Compare readings over time to spot gradual declines. - Inspect wiring and connections at each cleaning to catch rodent damage or corrosion early. ## Lighting and Pig Behavior Lighting does more than support vision. It shapes how pigs spend their time and how they interact with each other. Understanding these behavioral effects helps you make better lighting decisions. ### Feeding Behavior Pigs are diurnal animals, meaning they are naturally active during daylight hours. When given access to feed and light, pigs spread their feeding across the light period with peaks in the morning and late afternoon. A longer photoperiod gives pigs more opportunities to eat, which is why long photoperiods improve feed intake in newly weaned pigs. In the first days after weaning, some pigs do not eat at all. Bright light helps these pigs find the feeder and observe penmates eating. Social facilitation, where one pig learns to eat by watching another, is stronger in well-lit conditions. If you notice a group of pigs huddled away from the feeder in the first days after weaning, check light levels in that pen. A dark corner near the feeder may be discouraging exploration. ### Resting and Sleeping Behavior Pigs need a dark period to sleep properly. Sleep is not wasted time. It is when growth hormone is released and when the immune system performs maintenance. Pigs on continuous light may show more fragmented sleep and higher activity levels, which can increase energy expenditure and reduce growth efficiency. A 6 to 12 hour dark period each day is appropriate for nursery pigs. During the dark phase, pigs should settle into a resting posture within 30 to 60 minutes. If pigs remain active, vocal, or aggressive during the dark phase, check whether the barn is truly dark. Light leaks from timers, exit signs, or equipment can disrupt sleep. ### Aggression and Social Behavior Mixing pigs from different litters at weaning creates social stress. Pigs establish a dominance hierarchy through fighting in the first days after mixing. Lighting intensity and photoperiod can influence the severity of this aggression. Bright, even lighting helps pigs see each other clearly and may reduce fear-based aggression. Pigs that can see approaching penmates are less likely to react defensively. However, very long photoperiods can increase overall activity and therefore increase the number of aggressive encounters. The recommended phased photoperiod balances these effects by providing bright light during the mixing period and then reducing light hours as the hierarchy stabilizes. ### Stress Indicators Watch for behavioral signs that lighting conditions are wrong. Pigs that are constantly active and restless may be getting too much light or light that is too bright. Pigs that are lethargic and reluctant to move may be in conditions that are too dark or have no clear day-night rhythm. Frequent startle responses when lights change suggest abrupt transitions. Increased fighting and tail biting can indicate general stress that may be worsened by poor lighting. ## Lighting and Pig Health Lighting affects pig health through several pathways. Understanding these connections helps you recognize when lighting changes might improve herd health outcomes. ### Immune Function and Melatonin Melatonin is produced by the pineal gland during darkness. It regulates sleep and has antioxidant and immune-modulating properties. Pigs exposed to continuous light have lower melatonin levels and may show altered immune responses. A proper dark period supports normal melatonin production, which in turn supports immune function. This does not mean that long photoperiods are harmful. The research evidence shows that long photoperiods improve growth, and the immune effects are subtle. The practical answer is to provide a clear dark period of at least 6 hours each night so melatonin rhythms can function normally. ### Vitamin D Synthesis Pigs can synthesize vitamin D in their skin when exposed to ultraviolet light. Standard barn lighting does not provide meaningful UV output. If your nursery pigs are entirely indoors, they rely on dietary vitamin D rather than light exposure. Work with your nutritionist to ensure the diet meets vitamin D requirements for the indoor environment. Do not rely on lighting to provide vitamin D. ### Eye Health and Photophobia Pigs with eye injuries, conjunctivitis, or other ocular conditions may be sensitive to bright light. If you notice pigs squinting, keeping eyes closed, or avoiding well-lit areas, check for eye problems. Provide some shaded areas within pens, such as solid panels or partial covers, so pigs can choose their preferred light level. This is especially important for pigs recovering from illness. ### Circadian Disruption and Stress A disrupted circadian rhythm can increase stress hormone levels. Cortisol is a useful short-term response to challenges but becomes harmful when chronically elevated. High cortisol suppresses immune function, reduces growth, and increases susceptibility to disease. Maintaining a consistent daily light-dark cycle helps keep cortisol rhythms normal. Be consistent with your lighting schedule. Pigs are sensitive to changes in their daily routine. If you must change the photoperiod, do it gradually over several days rather than all at once. Sudden changes in photoperiod are themselves a stressor. ## Common Lighting Mistakes in Nursery Barns Even well-intentioned lighting programs fail when common mistakes creep in. Recognizing these problems helps you correct them quickly. ### Mistake 1: Relying on Visual Assessment The most common mistake is assuming the barn is bright enough because it looks bright to human eyes. Human vision adapts to low light, so a barn that looks fine may actually be well below the recommended intensity for pigs. Use a lux meter to verify actual light levels. Make monthly measurement a standard practice. ### Mistake 2: Ignoring Fixture Cleanliness Dust and grime accumulate on light fixtures quickly in a pig barn. A layer of dust can reduce light output by 30 to 50 percent. Fixtures that are never cleaned gradually dim until they are nearly useless. Put fixture cleaning on the regular chore list, not the occasional maintenance list. ### Mistake 3: Using the Same Photoperiod Year Round The optimal photoperiod may differ by season. In hot weather, reducing light hours can reduce pig activity and heat production during the hottest part of the day. In cold weather, longer light hours encourage activity that helps pigs stay warm. Adjust your photoperiod seasonally rather than setting it once and forgetting it. ### Mistake 4: Forgetting the Dark Period Some managers leave lights on 24 hours per day because they fear pigs will not eat in the dark. This fear is unfounded after the first week. Pigs learn quickly and will eat during the dark phase if feed is available. A continuous light program disrupts sleep and may increase stress. Always provide at least 6 hours of darkness. ### Mistake 5: Poor Fixture Placement Fixtures placed too high, too far apart, or in the wrong locations create uneven light distribution. Pigs in shadowed areas may not find feed or water as quickly. When designing or renovating a nursery, take time to calculate proper fixture spacing. When in doubt, add more fixtures rather than fewer. ### Mistake 6: Ignoring Light Leaks Light leaks from timers, door seals, and equipment can disrupt the dark period. A single bright LED on a controller can create enough light to disturb pig sleep. Walk the barn during the dark phase to check for light leaks. Seal gaps, cover indicator lights, and use blackout curtains on windows if needed. ### Mistake 7: Skipping the Adaptation Period Going directly from 24 hour light to a 12 hour photoperiod can stress pigs. The transition should be gradual. Reduce light hours by 1 to 2 hours per day over several days until you reach the target photoperiod. This gives pigs time to adjust their feeding and resting patterns. ## Monitoring and Recordkeeping for Lighting Programs A lighting program is only as good as the records that track it. Consistent monitoring helps you catch problems early and document the impact of lighting changes on pig performance. ### What to Record Keep a lighting log with the following information: - Date and time of each photoperiod change - Photoperiod settings on the timer or controller - Light intensity readings by pen and fixture location - Fixture cleaning dates - Bulb or tube replacements - Timer and dimmer checks - Any lighting-related observations, such as pigs avoiding certain pens or increased aggression Record this information in a simple spreadsheet or paper log kept in the barn office. Review the log monthly to spot trends. ### Linking Lighting Data to Pig Performance Connect lighting records to production data. Track average daily gain, feed intake, and mortality by nursery group. If you change your lighting program, compare performance before and after the change. This helps you determine whether the lighting adjustment had the desired effect. Work with your herd veterinarian or extension agent to interpret the data. They can help you distinguish lighting effects from other variables such as feed changes, health challenges, and season. ### When to Adjust the Program Review your lighting program at these times: - At the start of each nursery group, confirm the photoperiod schedule is correct for the stage. - After any major equipment change, such as new fixtures or a new controller. - When you notice behavioral changes in pigs, such as increased aggression or reduced feed intake. - When light intensity readings fall below target levels. - When seasonal temperature changes alter barn conditions. Do not change the lighting program frequently. Pigs benefit from consistency. Make changes deliberately and document the reason for each change. ## When to Call a Veterinarian or Extension Agent Most lighting problems can be solved by adjusting fixtures, schedules, or maintenance practices. However, some situations warrant professional help. ### Signs That Lighting Is Contributing to Health Problems If you see any of the following, contact your herd veterinarian: - Pigs show signs of eye irritation, such as excessive tearing, squinting, or cloudiness, that does not resolve with cleaning and lighting adjustments. - Pigs have unexplained increases in aggression, tail biting, or other injurious behaviors that persist despite lighting changes. - Pigs show poor growth or high mortality that cannot be explained by feed, water, ventilation, or disease. - Pigs appear excessively lethargic or unresponsive, which may indicate a deeper health issue. Your veterinarian can help rule out infectious causes and determine whether lighting is a contributing factor. ### When to Contact an Extension Agent Extension agents can help with lighting design, fixture selection, and program evaluation. Contact your local extension office when: - You are planning a new nursery barn or major renovation and need help with fixture layout. - You want to compare lighting options and calculate return on investment. - You need help interpreting research on photoperiod or light intensity. - You want to develop a lighting standard operating procedure for your farm. Extension agents have access to current research and can connect you with other producers who have solved similar problems. ### Regulatory and Safety Considerations Lighting systems must comply with electrical codes and safety standards. If you are installing new fixtures or rewiring, use a licensed electrician. Ensure all fixtures are rated for dusty, humid environments. Check that emergency lighting and exit signs are functional. These are not optional features. They protect both pigs and people. If you suspect that lighting is affecting pig welfare in a way that could violate animal welfare standards, document your observations and contact your veterinarian or extension agent immediately. Early intervention is always better than waiting for a problem to escalate. ## Frequently Asked Questions ### How many hours of light do nursery pigs need per day? For the first 7 to 10 days after weaning, provide 20 to 24 hours of light per day to maximize feed intake and help pigs learn feeder and drinker locations. After that adaptation period, reduce to 12 to 16 hours of light and 8 to 12 hours of dark. The dark period is essential for normal sleep and melatonin production. A minimum of 6 hours of uninterrupted darkness each day is recommended. ### What light intensity is best for nursery pigs? Target 100 to 150 lux at pig eye level in general pen areas. Feeder and drinker zones should be at the higher end of that range, around 150 to 200 lux. Inspection aisles and sorting areas should have at least 200 lux. Measure actual light levels with a lux meter rather than estimating by eye. Clean fixtures regularly because dust can reduce light output by 30 to 50 percent. ### Should I leave lights on 24 hours a day for newly weaned pigs? A 24 hour light period for the first 3 to 7 days after weaning is a common and effective strategy. It gives pigs maximum opportunity to find feed and water during the critical adaptation window. However, do not continue 24 hour lighting beyond the first week. Pigs need a daily dark period for proper sleep and hormone regulation. Step the photoperiod down gradually to 12 to 16 hours of light per day. ### Do pigs need darkness to sleep? Yes. Pigs, like most mammals, produce melatonin during darkness, and melatonin supports normal sleep. Pigs on continuous light may show fragmented sleep and elevated stress hormones. Provide a consistent dark period of at least 6 hours each night. Make sure the dark period is truly dark by checking for light leaks from timers, indicator lights, and windows. ### What color of light is best for nursery pigs? Use cool white light with a color temperature between 4000K and 5000K. This range provides neutral to cool white light that supports good visibility and color discrimination. Avoid warm yellow light, which can make the barn feel dim even at adequate intensity. Both LED and fluorescent fixtures are available in this color temperature range. ### How often should I clean nursery barn light fixtures? Clean light fixtures every 4 to 6 weeks. Barn dust and grime accumulate quickly and can cut light output by 30 to 50 percent. Use a dry cloth or a vacuum with a soft brush attachment. Do not use water near electrical components. Include fixture cleaning in your regular chore schedule rather than treating it as an occasional task. ### Can lighting affect nursery pig aggression? Yes. Bright, even lighting helps pigs see each other clearly and may reduce fear-based aggression during mixing. However, very long photoperiods increase overall activity, which can increase the number of aggressive encounters. The recommended approach is bright light during the mixing period and then a gradual reduction to a 12 to 16 hour photoperiod as the social hierarchy stabilizes. ### Do I need a light timer or can I switch lights manually? Use an automatic timer or controller. Manual switching leads to inconsistent photoperiods, especially when staff are busy or shifts change. Digital timers with battery backup are inexpensive and reliable. If your barn controller supports lighting schedules, program the photoperiod there and set an alarm for any controller failures. Consistency is key for pig welfare and performance. ## Related Farming Guides This section will be populated with links to related farming guides on nursery management, pig behavior, and barn environmental control. Check back for updates or use the site search to find additional resources on swine production. ## 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.