# Sheep Barn Environmental Monitoring: Temperature, Humidity, and Air Quality


## Key Takeaways

- Barn temperature should be maintained between 32-70°F (0-21°C) for adult sheep, with critical thresholds above 85°F (29°C) combined with high humidity, as heat stress significantly reduces feed intake and fertility.
- Barn humidity should ideally be between 40-70%, with levels above 80% for extended periods posing a critical risk factor for the proliferation of bacteria causing pneumonia and foot rot.
- Ammonia levels must be kept below 10 ppm continuously, as concentrations exceeding 25 ppm directly damage lung tissue, impairing respiratory function and reducing weight gain.
- Ventilation is paramount, with target airflow of 10-30 air changes per hour in winter (more in summer), as insufficient airflow (less than 4 air changes/hour) leads to stale air carrying pathogens and moisture.
- Continuous monitoring of temperature, humidity, and air quality (ammonia, CO2) using strategically placed sensors (at sheep height) and diligent recordkeeping are essential for proactive management and preventing clinical signs of distress.

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Sheep barn environmental monitoring is the practice of tracking temperature, humidity, and air quality inside your housing facility to protect flock health, improve growth rates, and reduce the risk of respiratory disease. This guide is for sheep producers who house their animals for part or all of the year, whether you run a small farm flock of 20 ewes or a commercial operation with several hundred head. You will learn what conditions to target, which sensors to buy, how to install and maintain them, and how to interpret the data so you can act before problems become costly.

## At a Glance

| Parameter | Target Range | Critical Threshold | Why It Matters |
|---|---|---|---|
| Barn temperature | 32 to 70 F (0 to 21 C) for adult sheep | Above 85 F (29 C) with high humidity | Heat stress reduces feed intake and fertility |
| Barn humidity | 40 to 70 percent | Above 80 percent for extended periods | High moisture drives pneumonia and foot rot |
| Ammonia | Below 10 ppm continuous | Above 25 ppm | Damages lungs and reduces weight gain |
| Carbon dioxide | Below 3000 ppm | Above 5000 ppm | Indicates poor ventilation |
| Airflow | 10 to 30 air changes per hour in winter, more in summer | Less than 4 air changes per hour | Stale air carries pathogens and moisture |
| Light | 8 to 12 hours for non-breeding, 14 to 16 for breeding | Sudden changes disrupt cycles | Affects reproduction and wool growth |

The single most important takeaway is this: ventilation drives everything. You can install the best sensors in the world, but if you do not adjust your ventilation system based on what those sensors tell you, the data is worthless. Start with basic temperature and humidity monitoring, add ammonia detection once you have the fundamentals in place, and build a daily recordkeeping habit that lets you spot trends before they become emergencies.

## Why Sheep Barn Environmental Monitoring Matters

Sheep are more resilient than many livestock species, but that hardiness has a limit. When you house sheep, you take control of their environment. That means you also take responsibility for the air they breathe and the conditions they endure. A poorly monitored barn can quietly undermine everything else you do well, from genetics to nutrition to parasite control.

The respiratory system of a sheep is delicate. The lungs are the largest organ surface exposed to the outside world, and they have no way to filter out ammonia, dust, or mold spores. When those irritants build up in a closed barn, the sheep's natural defenses weaken. Bacteria that normally live harmlessly in the upper airway can move deeper into the lungs and cause pneumonia. Pneumonia is one of the leading causes of death in housed sheep, and it often starts with an environmental problem that could have been caught early.

Temperature swings are equally damaging. Sheep can handle cold far better than heat, especially when they have a full fleece. But a barn that gets too hot, particularly during late pregnancy or breeding season, causes ewes to eat less. Lower feed intake means lower lamb birth weights and reduced milk production. Heat stress during breeding can also lower conception rates.

Humidity is the hidden amplifier. High humidity makes heat feel worse and cold feel worse. It also keeps bedding damp, which promotes the growth of bacteria that cause foot rot and mastitis. When humidity stays above 80 percent for several days, you will see problems in the feet and udders even if the temperature looks acceptable.

Air quality ties all of these together. Ammonia comes from urine and manure breaking down in bedding. Carbon dioxide comes from the sheep themselves when they exhale. Dust comes from feed and bedding. When ventilation is inadequate, all of these accumulate. The sheep are effectively breathing their own waste products.

The good news is that all of these problems are preventable. Environmental monitoring gives you the information you need to make adjustments early, before the flock shows clinical signs of distress. A sheep that is panting, coughing, or standing with its head down is already in trouble. A well-monitored barn lets you fix the problem days before that sheep starts showing symptoms.

## Understanding Temperature Requirements for Housed Sheep

Temperature management starts with knowing what sheep actually need. The thermoneutral zone is the range of temperatures where a sheep does not have to expend extra energy to stay warm or cool down. For adult sheep with a full fleece, that zone is roughly 32 to 70 F (0 to 21 C). Within that range, the sheep maintains its body temperature without burning extra calories.

Below 32 F, sheep start using energy to stay warm. They will eat more to compensate, which raises your feed costs. If the barn is drafty and wet, the effective temperature can be much lower than what the thermometer reads. A wet fleece loses its insulating value almost completely, and a sheep that is wet and cold can suffer hypothermia even at temperatures above freezing.

Above 70 F, sheep start to feel heat stress. The fleece that protects them from cold also traps heat. They cannot sweat effectively, so they rely on panting to cool down. Panting is inefficient and uses energy that could go toward growth or reproduction. At 85 F (29 C) with high humidity, even healthy adult sheep will show visible signs of distress.

The critical periods for temperature monitoring are late gestation, lambing, and the first few weeks after lambing. Newborn lambs have almost no body fat and a thin, wet coat. They need a dry, draft-free environment at 50 to 60 F (10 to 15 C) for the first 24 to 48 hours. After that, they can handle cooler temperatures if they have access to a warm creep area and their mother's colostrum.

For adult ewes, the most dangerous temperature scenario is a sudden heat spike in late pregnancy. Ewes that are carrying twins or triplets generate more internal heat because of the metabolic demands of the lambs. When ambient temperature rises above 80 F (27 C), these ewes are at risk of pregnancy toxemia and reduced milk production.

Here is how to set up your temperature monitoring system:

First, determine the coldest and warmest spots in your barn. Temperature is rarely uniform. The center of the barn is usually warmer than the walls. The area near the ridge is warmer than the floor. The north side is colder than the south side. Walk through your barn at different times of day and in different weather conditions to map these zones.

Second, place temperature sensors at sheep height, not at human height. A sensor mounted at 6 feet gives you the temperature at your head, not at the sheep's nose. Mount sensors at 2 to 4 feet off the floor, where the sheep actually live. For lambing pens, mount sensors lower, around 1 to 2 feet, to capture the conditions that newborn lambs experience.

Third, use multiple sensors. One sensor in the middle of the barn tells you very little about conditions at the ends. For a barn that is 100 feet long, you need at least three sensors: one at each end and one in the middle. For a barn with multiple rooms or pens, each room needs its own sensor.

Fourth, record temperatures at consistent times. Take readings in the morning before you open the barn and in the evening after the animals have settled. These two readings give you the daily range. A barn that swings more than 20 degrees between morning and evening is poorly insulated or overventilated.

Fifth, respond to trends, not single readings. A single hot afternoon does not necessarily require action. But three consecutive afternoons above 80 F means you need to increase airflow, provide shade, or consider misting. A single cold night is not an emergency, but a week of below-freezing temperatures with high wind chill requires more bedding and draft protection.

## Humidity Monitoring and Moisture Control

Humidity is the variable that most sheep producers ignore until it becomes a crisis. Relative humidity measures how much moisture is in the air compared to how much it can hold at that temperature. Warm air holds more moisture than cold air. When warm, moist air cools, it releases that moisture as condensation on walls, ceilings, and bedding.

The ideal relative humidity for a sheep barn is 40 to 70 percent. Below 40 percent, the air is too dry, which can cause dust problems and irritate the respiratory tract. Above 70 percent, you are entering the danger zone. At 80 percent and above, you will see condensation, wet bedding, and a rapid increase in bacterial and fungal growth.

The sources of moisture in a sheep barn are numerous. Each adult sheep exhales about 1 to 2 gallons of water vapor per day. Urine adds significant moisture, especially if the bedding is not absorbing it. Manure adds moisture as it decomposes. Waterers spill. Rain and snow come in through open doors. In a barn with 100 ewes, you are adding hundreds of gallons of moisture to the air every week.

High humidity creates a cascade of problems. Wet bedding loses its insulating value, so sheep get cold even when the air temperature is fine. Wet bedding also promotes the growth of bacteria that cause foot rot, which is one of the most painful and economically damaging diseases in sheep. Mastitis-causing organisms thrive in damp environments. The combination of high humidity and high temperature is particularly dangerous, because it prevents sheep from cooling themselves through panting.

Here is how to monitor and control humidity:

Purchase a hygrometer, which is a device that measures relative humidity. You can buy a digital hygrometer for under 20 dollars, and most modern temperature sensors include humidity measurement as a standard feature. Place hygrometers next to your temperature sensors so you can track both variables together.

Take humidity readings at the same times you take temperature readings. Record both in the same log so you can see how they interact. A common pattern is for humidity to rise overnight as the barn cools and the sheep exhale moisture into the air. If morning humidity is above 80 percent, you have a ventilation problem that needs attention.

Look for condensation on windows, metal surfaces, and the underside of the roof. Condensation is a visible sign that the air is saturated and that moisture is falling back onto the sheep and bedding. If you see condensation, your ventilation is inadequate regardless of what the hygrometer says.

The primary tool for humidity control is ventilation. Moving air carries moisture out of the barn and brings in drier air from outside. In winter, you face a tradeoff between keeping the barn warm and removing moisture. The solution is not to close the barn completely, but to ventilate at a rate that removes moisture while conserving heat.

Bedding management is the second tool. Deep bedding systems absorb significant moisture if they are maintained properly. Add fresh bedding regularly, and remove wet spots immediately. A barn that smells of ammonia is a barn where bedding management has failed, regardless of what the sensors say.

The third tool is water system maintenance. Fix leaking waterers promptly. Position waterers over drained areas so spills do not soak into bedding. In winter, check that waterers are not overflowing due to ice blockage in the supply lines.

## Air Quality Monitoring: Ammonia, Carbon Dioxide, and Dust

Air quality is the most complex and the most important aspect of sheep barn environmental monitoring. The three main pollutants are ammonia, carbon dioxide, and particulate matter (dust). Each comes from a different source and requires a different control strategy.

Ammonia is a colorless gas with a sharp, irritating smell. It comes from the breakdown of urea in urine and manure. The bacteria that perform this breakdown need warmth and moisture, so ammonia production increases in summer and in poorly ventilated barns. At low concentrations, ammonia irritates the eyes and respiratory tract. At higher concentrations, it damages the delicate lining of the lungs and makes sheep more susceptible to pneumonia.

The Occupational Safety and Health Administration sets a permissible exposure limit of 50 ppm for human workers over an 8 hour shift. Sheep are more sensitive than humans. Research consistently shows that sheep exposed to ammonia above 25 ppm have reduced feed intake, slower growth, and increased respiratory disease. The practical target for a sheep barn is below 10 ppm. At that level, you should not be able to smell ammonia when you walk into the barn. If you can smell it, your sheep are breathing levels that are too high.

Carbon dioxide is produced by the sheep themselves as they exhale. It is not directly toxic at the levels found in barns, but it is an excellent indicator of ventilation adequacy. If carbon dioxide is high, it means the air is stale and other pollutants are also accumulating. Indoor carbon dioxide levels should stay below 3000 ppm. Levels above 5000 ppm indicate a serious ventilation failure.

Dust comes from feed, bedding, and the sheep themselves. Feed dust is the most common problem, especially when you are handling hay or grain. Dust particles are small enough to reach the deep lung, where they cause inflammation and provide a surface for bacteria to attach. Sheep that are already stressed by ammonia or temperature extremes are more susceptible to dust-related respiratory problems.

Here is how to measure air quality in your barn:

Use your nose as the first line of detection. If you can smell ammonia when you enter the barn, the level is too high. If your eyes water or your throat feels irritated after 10 minutes inside, the air quality is seriously degraded. These subjective signs are reliable indicators that action is needed, and they cost nothing.

For quantitative measurement, use ammonia test tubes or an electronic ammonia sensor. Test tubes, also called gas detection tubes, are glass tubes filled with a chemical that changes color when exposed to ammonia. You break the ends off, attach a hand pump, and draw a measured volume of air through the tube. The color change tells you the concentration. These tubes are accurate and inexpensive, but they only give you a single reading at a single point in time.

Electronic ammonia sensors provide continuous monitoring. They cost more, typically 100 to 300 dollars for a good unit, but they give you real time data and can be connected to an alarm system. Place the sensor at sheep height in the center of the barn, away from direct airflow from fans or open doors. Calibrate the sensor according to the manufacturer's instructions, usually every 3 to 6 months.

Carbon dioxide monitors are widely available and relatively inexpensive. Many indoor air quality monitors measure carbon dioxide, temperature, and humidity in a single unit. Place one in the center of the barn and one near the end where ventilation is weakest. Carbon dioxide readings above 3000 ppm tell you to increase ventilation even if you cannot smell anything wrong.

Dust is harder to measure without specialized equipment. The practical approach is visual inspection. Shine a flashlight across a beam of light in the barn. If you can see dust particles floating in the air, the dust level is too high. If dust settles on horizontal surfaces within a few hours of cleaning, you have a dust problem. The solution is usually to change how you handle feed, not to add more ventilation.

## Ventilation Systems and How to Adjust Them

Ventilation is the single most important environmental control in a sheep barn. It removes moisture, ammonia, carbon dioxide, and dust. It brings in fresh oxygen. It helps regulate temperature. No amount of monitoring is useful if you cannot act on the data, and ventilation is how you act.

There are two types of ventilation: natural and mechanical. Natural ventilation relies on wind and temperature differences to move air through the barn. It uses openings in the walls, ridge vents, and eave inlets. Mechanical ventilation uses fans to force air movement. Most commercial sheep barns use a combination of both.

Natural ventilation works on the stack effect. Warm air rises and exits through ridge vents at the top of the barn. This creates a slight vacuum that draws cooler air in through openings at the sides. The wind adds to this effect by pushing air through windward openings and pulling it out through leeward openings.

The key to natural ventilation is having enough opening area. As a general rule, the total inlet area should be equal to the total outlet area. For a barn with a ridge vent, the ridge opening should be at least 1 inch for every 10 feet of building width. Side openings should be adjustable so you can control airflow in winter versus summer.

Mechanical ventilation uses exhaust fans to pull air out of the barn, creating negative pressure that draws fresh air in through controlled inlets. The advantage of mechanical ventilation is that it works regardless of wind or temperature. The disadvantage is that it costs money to run and requires maintenance.

The ventilation rate is measured in air changes per hour. One air change means the entire volume of air in the barn is replaced. In winter, a sheep barn needs 4 to 10 air changes per hour to remove moisture and ammonia while conserving heat. In summer, 20 to 40 air changes per hour may be needed to keep temperatures down.

Here is how to adjust your ventilation system based on monitoring data:

If ammonia is above 10 ppm, increase ventilation. Open more inlets, turn on additional fans, or both. Check that the inlets are not blocked by stored equipment or feed. Check that the exhaust fans are working and that the blades are clean. A fan that is covered in dust moves far less air than a clean fan.

If humidity is above 80 percent, increase ventilation. High humidity means moisture is not being removed. In winter, you may need to increase ventilation even if it means the barn gets cooler. A dry barn at 40 F is healthier for sheep than a wet barn at 50 F.

If carbon dioxide is above 3000 ppm, increase ventilation. Carbon dioxide is the best indicator that the barn is not getting enough fresh air. If your carbon dioxide monitor is in the center of the barn and reads high, check the end of the barn. The problem is often at the far end, where air becomes increasingly stale as it travels through the building.

If temperature is above 80 F and humidity is above 70 percent, you have a dangerous combination. Increase ventilation to the maximum and consider adding evaporative cooling. Misting systems can reduce temperature by 10 to 15 degrees, but they also add moisture to the air. Use them only when humidity is below 60 percent.

In winter, the most common mistake is closing the barn too tightly to conserve heat. A tightly closed barn becomes a humid, ammonia laden chamber that destroys sheep health. The correct approach is to ventilate at a rate that removes moisture and pollutants while using insulation and bedding to maintain temperature. A well insulated barn with controlled ventilation is warmer and healthier than a poorly insulated barn with no ventilation.

## Selecting and Installing Sensors

The market for environmental sensors has grown rapidly in recent years, and you can now buy reliable equipment at reasonable prices. The key is to match the sensor to your needs and to install it correctly. A sensor that is not calibrated or not placed properly is worse than no sensor at all, because it gives you false confidence.

For temperature and humidity, you have three main options: standalone units, multi parameter monitors, and smart systems.

Standalone temperature and humidity sensors are the simplest and cheapest option. You can buy a digital thermometer and hygrometer combination for 15 to 30 dollars. These units run on batteries and display current readings on a small screen. They are adequate for small barns and for producers who are willing to check readings manually several times per day.

Multi parameter monitors measure temperature, humidity, and carbon dioxide in a single unit. They cost 100 to 300 dollars and display all three readings on one screen. Some models also calculate dew point and heat index. These are the best value for most producers because they give you the three most important measurements in one device.

Smart systems connect to your phone or computer and provide continuous monitoring with alerts. They cost 300 to 1000 dollars or more, depending on the number of sensors and the features. Smart systems let you check conditions remotely, receive text alerts when conditions exceed your thresholds, and log data automatically. They are worth the investment for larger operations and for producers who are away from the barn for extended periods.

For ammonia, you have two main options: test tubes and electronic sensors. Test tubes are the most reliable for spot checks. They cost 50 to 100 dollars for a box of 10 tubes plus the hand pump. Electronic ammonia sensors cost 200 to 500 dollars and provide continuous monitoring. They require regular calibration and replacement of the sensing element.

Here is how to install sensors for maximum accuracy:

Mount temperature and humidity sensors at sheep height, 2 to 4 feet above the floor. Do not mount them directly above heat sources, waterers, or doors. Keep them away from direct sunlight, which causes artificially high readings. Protect them from physical damage by mounting them on a wall or post.

Place at least one sensor in each distinct area of the barn. A lambing area has different requirements than a finishing area. A creep area for lambs has different conditions than the main pen. Each area needs its own sensor.

Place ammonia sensors near the floor, because ammonia is heavier than air and accumulates at the lowest point. Do not place them directly over a manure pack or a urine soaked area, which will give you artificially high readings. Place them 1 to 2 feet above the floor, in a central location.

Place carbon dioxide sensors at sheep height in the center of the barn. Carbon dioxide is produced by the sheep themselves, so the highest concentrations are at the level where the sheep are breathing.

Check sensor accuracy regularly. You can check a thermometer against a known reference, such as a second thermometer that you know is accurate. You can check a hygrometer with the wet bulb dry bulb method or by wrapping the sensor in a damp cloth and comparing the reading to the expected value. Follow the manufacturer's calibration schedule for electronic sensors.

## Recordkeeping and Data Interpretation

Environmental monitoring is only useful if you record the data and review it regularly. The goal is to spot trends before they become problems. A single high ammonia reading is a warning. Three consecutive high readings are a pattern that requires action.

Start with a simple logbook or spreadsheet. Record the date, time, outside temperature, inside temperature, humidity, ammonia level if measured, carbon dioxide level if measured, and any observations about the sheep. Note anything unusual, such as coughing, panting, or reduced feed intake. Note any changes you made to the ventilation system or bedding.

Take readings at the same times every day. Morning and evening readings are the minimum. If you have a smart system, it will log data continuously, but you still need to review it. Set aside 10 minutes each day to review the data and look for patterns.

Use the data to establish baselines for your barn. Every barn is different. A barn with poor insulation will have wider temperature swings than a well insulated barn. A barn with a deep bedding pack will have different ammonia patterns than a barn cleaned out daily. Once you know your baseline, you can identify abnormal conditions more quickly.

Look for these patterns:

A steady rise in ammonia over several days usually means bedding management is failing or ventilation is decreasing. Check the bedding and the fans.

A spike in humidity after a storm or a period of wet weather means outside moisture is entering the barn. Check for leaks and keep doors closed during rain.

A morning temperature that is much lower than the evening temperature suggests poor insulation or excessive ventilation at night. Adjust the ventilation schedule.

A correlation between high ammonia and increased coughing or nasal discharge in the sheep confirms that air quality is affecting health. Take action immediately.

Review your records monthly to identify longer term trends. Did the barn perform well during last winter? What changes can you make before next winter? Did the ventilation system keep up during the summer heat? What upgrades are needed?

Share your records with your veterinarian and your extension agent. They can help you interpret the data and recommend changes. They can also spot patterns that you might miss because you see the barn every day.

## Common Mistakes in Sheep Barn Environmental Monitoring

The most common mistake is buying sensors and then ignoring them. A sensor that is installed but never checked is worse than useless, because it creates the illusion that you are monitoring conditions when you are not. Set a schedule for checking sensors and reviewing data, and stick to it.

The second most common mistake is placing sensors in the wrong location. A sensor mounted at 8 feet above the floor reads the temperature at the ceiling, not at the sheep. A sensor placed directly in front of a fan reads the airflow from the fan, not the ambient conditions. A sensor placed in direct sunlight reads 10 to 20 degrees higher than the actual air temperature. Take the time to place sensors correctly.

The third mistake is reacting to a single reading. Environmental conditions fluctuate naturally. A temperature of 85 F at 2 PM on a hot summer afternoon may be normal and temporary. A humidity reading of 85 percent on a foggy morning may drop to 60 percent by noon. Do not make major changes based on one reading. Look for patterns over 24 to 48 hours.

The fourth mistake is ignoring the interaction between temperature and humidity. High temperature with low humidity is uncomfortable but manageable. High temperature with high humidity is dangerous, because the sheep cannot cool themselves through panting. High humidity with low temperature makes the sheep feel colder than the thermometer suggests. Always consider both variables together.

The fifth mistake is neglecting ventilation maintenance. Fans accumulate dust, belts stretch, and motors wear out. A fan that is running but moving half the air it should is a hidden problem. Clean fan blades monthly, check belts quarterly, and replace worn motors before they fail.

The sixth mistake is not having a backup plan for power failures. A summer power outage can be deadly to a barn full of sheep. A winter power outage can freeze water lines and cause hypothermia. Have a generator that is tested monthly, and know how to open the barn manually to provide emergency ventilation.

The seventh mistake is treating monitoring as a substitute for management. Sensors tell you what is happening, but they do not fix problems. You still need to manage bedding, adjust ventilation, and care for the sheep. Monitoring is a tool to support your management, not a replacement for it.

## When to Call a Veterinarian or Extension Agent

Environmental monitoring can prevent many problems, but it cannot prevent all of them. Some situations require professional help. Knowing when to call is part of responsible flock management.

Call your veterinarian immediately if you see any of these signs in your flock:

Multiple sheep coughing, with nasal discharge or rapid breathing. This could be pneumonia, which requires prompt treatment with antibiotics.

Sheep that are open mouth breathing or panting heavily even after you have reduced temperature and increased ventilation. This indicates severe heat stress that may require electrolyte therapy.

Ewes that are off feed for more than 24 hours, especially in late pregnancy. This could be pregnancy toxemia, which is a medical emergency.

Lambs that are weak, lethargic, or not nursing. This could be a sign of environmental stress, infection, or inadequate colostrum.

Sudden death of one or more sheep. This requires immediate investigation to rule out infectious disease.

Call your veterinarian or extension agent for a consultation if you see these patterns:

Ammonia levels that stay above 25 ppm despite your best efforts to improve ventilation and bedding.

Recurrent respiratory problems in the flock, even after treatment. This suggests a chronic environmental problem that needs a professional assessment.

A gradual decline in feed intake, weight gain, or wool production that you cannot explain. Environmental stress may be the cause.

A high incidence of foot rot or mastitis. These diseases are often linked to moisture problems in the barn.

Your veterinarian can perform a barn walkthrough, take air quality measurements, and recommend changes. Your extension agent can provide educational materials, connect you with other producers, and help you access technical assistance programs.

Before you call, gather your monitoring records. Write down the temperature, humidity, and ammonia readings for the past week. Note any changes you have made to the ventilation system or bedding. Note the number of animals affected and the specific signs you have observed. This information will help the veterinarian or extension agent diagnose the problem more quickly.

## Building an Environmental Monitoring Plan

A monitoring plan does not need to be complicated, but it needs to be written down and followed. Here is a step by step process for building a plan that works for your operation.

Step one: Map your barn. Draw a simple floor plan and mark the locations of all pens, doors, windows, fans, and ridge vents. Identify the areas where sheep spend the most time and the areas where problems are most likely to occur.

Step two: Determine your sensor needs. Based on the size of your barn and the number of animals, decide how many sensors you need and where to place them. Start with temperature and humidity sensors in each major area. Add carbon dioxide monitoring if you have a mechanically ventilated barn. Add ammonia monitoring if you have had respiratory problems or if you use a deep bedding system.

Step three: Purchase and install your equipment. Choose sensors that are appropriate for your budget and your level of technical comfort. Install them according to the guidelines in this article. Calibrate them before you start using them.

Step four: Establish your baseline. Take readings for two to four weeks and record them in your logbook. Note the normal ranges for your barn under different weather conditions. This baseline will help you identify abnormal conditions in the future.

Step five: Set your thresholds. Based on the targets in this article and your baseline data, decide what conditions trigger action. For example, you might decide to increase ventilation when ammonia exceeds 10 ppm or when humidity exceeds 75 percent for more than 24 hours.

Step six: Create a response plan. Write down what you will do when each threshold is exceeded. For example, if humidity exceeds 80 percent, you will increase ventilation, add bedding, and check for leaks. Having a written plan helps you respond quickly and consistently.

Step seven: Schedule your monitoring activities. Decide when you will take readings, when you will review data, and when you will calibrate sensors. Put these tasks on your calendar so they become routine.

Step eight: Review and adjust your plan quarterly. Environmental conditions change with the seasons, and your monitoring plan should change too. Review your records, identify what worked and what did not, and make adjustments before the next season.

## Frequently Asked Questions

**How often should I check the temperature and humidity in my sheep barn?**

At minimum, check temperature and humidity twice daily, once in the morning and once in the evening. This gives you the daily range and lets you spot trends. If you have a smart monitoring system, check the data at least once daily and review the trends on a weekly basis. During extreme weather, such as heat waves or cold snaps, check more frequently.

**What is the best temperature for a sheep barn in winter?**

For adult sheep with a full fleece, the ideal barn temperature in winter is 32 to 50 F (0 to 10 C). The sheep are comfortable, feed efficiency is good, and moisture can be controlled with proper ventilation. Do not try to keep the barn above 60 F (15 C) in winter. The energy cost is high, and the temperature swings between inside and outside can cause more problems than the cold itself.

**How do I know if my barn has an ammonia problem?**

Use your nose. If you can smell ammonia when you enter the barn, the level is above 10 ppm and your sheep are being affected. For a quantitative measurement, use ammonia test tubes or an electronic sensor. If ammonia is above 10 ppm, increase ventilation and improve bedding management. If it is above 25 ppm, take immediate action to protect sheep health.

**Can I use a regular household thermometer and hygrometer in my barn?**

You can use them, but they may not be durable enough for barn conditions. Household units are not designed for high humidity, dust, or temperature extremes. They may fail quickly or give inaccurate readings. Look for units designed for agricultural or greenhouse use, which are more durable and have a wider measurement range.

**What is the best way to reduce humidity in a sheep barn without losing heat in winter?**

The answer is controlled ventilation. You need to remove moist air and bring in drier outside air, even if that means the barn cools slightly. A well insulated barn with adjustable inlets and a ridge vent can maintain temperature while removing moisture. Adding fresh bedding also helps, because dry bedding absorbs moisture from the air.

**How many air changes per hour does my sheep barn need?**

In winter, aim for 4 to 10 air changes per hour. This removes moisture and ammonia while conserving heat. In summer, aim for 20 to 40 air changes per hour to control temperature. If you have a mechanical ventilation system, you can adjust the fan speed to achieve these rates. If you rely on natural ventilation, adjust the openings to increase or decrease airflow.

**Should I monitor air quality in an open sided barn?**

Open sided barns have fewer air quality problems because natural ventilation is continuous. However, temperature and humidity monitoring is still useful, especially in summer when heat stress is a concern. If you have a semi open barn with partial walls, you may still see ammonia buildup in the more enclosed areas.

**What should I do if my sheep are coughing but the barn conditions look normal on my sensors?**

Do not assume the sensors are wrong, but do not assume they are right either. Check the sensors for accuracy and placement. Then look for other causes of coughing, such as parasites, viral infections, or dusty feed. If the coughing persists, call your veterinarian. Environmental monitoring is one tool, but it is not the only tool.

## Related Farming Guides

This section will be populated with links to related farming guides on [sheep housing](/knowledge/animal-farming/alternative-livestock/sheep-housing-shelter-design-considerations), ventilation design, respiratory disease prevention, and flock health management. Check back for updates or browse the farming guide library for additional resources.

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## References

- American Consortium for [Small Ruminant Parasite Control](/knowledge/veterinary-medicine/food-animal-medicine/small-ruminant-parasite-control-diagnostic-strategies-anthelmintic-stewardship) (ACSRPC): https://www.wormx.info/
- USDA APHIS Sheep Health: https://www.aphis.usda.gov/livestock-poultry-disease/sheep-goats
- FAO Sheep and Goat Production: https://www.fao.org/animal-production/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.