Broiler House Ammonia Control: Monitoring and Reduction

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

Key Takeaways

Ammonia formation in broiler litter is driven by microbial breakdown of uric acid and undigested nitrogen, accelerated by heat and moisture; maintaining litter moisture between 20-30% is the most critical controllable factor.
Ammonia levels above 25 parts per million (ppm) at bird height cause measurable harm, including reduced weight gain, increased feed conversion ratios, respiratory tract damage, and immune suppression.
Accurate ammonia monitoring requires measuring at bird height (not human standing height) using a calibrated electrochemical meter, with readings below 10 ppm considered acceptable and above 25 ppm requiring immediate intervention.
Proactive management, including pre-flock litter preparation (removing wet cake, aeration), maintaining adequate minimum ventilation even in cold weather (0.3-0.5 cfm/bird often needed), and using pH-lowering litter amendments (e.g., sodium bisulfate, aluminum sulfate) are crucial for reduction.
The brooding period presents the highest risk due to immature chick respiratory systems and peak ammonia production; maintaining higher ventilation rates and close monitoring (at least twice daily) during this phase is paramount.

Ammonia buildup in broiler houses is one of the most common and costly problems in poultry production. High ammonia levels damage bird health, reduce weight gain, increase feed conversion ratios, and make flocks more susceptible to respiratory disease. This guide covers the causes of ammonia in broiler litter, how to measure ammonia accurately, practical steps to reduce ammonia before and during a flock, and how to decide when ammonia levels require immediate action. It is written for broiler growers, farm managers, and poultry technicians who need practical troubleshooting guidance they can apply in real production conditions.

At a Glance

Ammonia forms when bacteria break down uric acid and undigested nitrogen in poultry litter. Heat and moisture accelerate the process.
Keep ammonia below 10 parts per million (ppm) at bird level whenever possible. Levels above 25 ppm cause measurable harm to bird health and performance.
Measure ammonia at bird height, not at human standing height. Use a reliable meter and calibrate it regularly.
Litter moisture is the single most controllable factor. Keep litter moisture between 20 and 30 percent.
Increase ventilation in cold weather even if it costs fuel. The performance loss from ammonia far exceeds heating costs.
Use litter amendments that lower pH when you need rapid ammonia reduction.
Remove wet caked litter between flocks and manage drinker systems to prevent wet spots.
Never rely on your nose alone. Human noses adapt to ammonia within minutes and cannot judge safe levels.

Understanding Ammonia in Broiler Houses

Ammonia is a colorless gas with a sharp, pungent odor. It forms in poultry litter through the microbial breakdown of nitrogen compounds, primarily uric acid and undigested protein in the birds' manure. Broilers produce uric acid as their main nitrogen waste product, and bacteria in the litter convert that uric acid into ammonia through a series of enzymatic steps.

The key factors that drive ammonia production are temperature, moisture, litter pH, and the amount of nitrogen available in the litter. Warm conditions speed up bacterial activity. Moist litter provides the environment bacteria need to thrive. Higher pH favors the conversion of ammonium into ammonia gas. And more nitrogen in the litter means more raw material for ammonia generation.

Ammonia does not stay evenly distributed in a broiler house. It tends to be highest near the litter surface, where birds breathe, and lower near the ceiling where ventilation exhausts it. Ammonia also accumulates in pockets where air movement is poor, such as corners, along sidewalls, and near brooders during cold weather. This uneven distribution means that a single reading from one location can mislead you about the true conditions in the house.

The season matters greatly. In warm weather, ventilation rates are high enough to remove ammonia as fast as it forms. In cold weather, growers often reduce ventilation to conserve heat, and ammonia builds up quickly. Spring and fall flocks can be especially challenging because daytime temperatures fluctuate, and ventilation settings that work in the morning may be inadequate by afternoon.

How Ammonia Affects Broiler Health and Performance

Ammonia is a water-soluble gas that dissolves in the moisture of the respiratory tract and eyes. When birds inhale ammonia, it irritates the mucous membranes of the trachea and lungs. The cilia, tiny hair-like structures that sweep mucus and debris out of the respiratory system, become paralyzed and eventually destroyed with prolonged exposure. This damage opens the door for secondary infections, especially respiratory diseases like Newcastle disease, infectious bronchitis, and colibacillosis.

Birds exposed to high ammonia also show reduced feed intake and slower growth. The irritation causes discomfort, and birds spend less time eating and more time resting with their heads tucked. Studies conducted at university poultry research facilities have consistently shown that broilers raised in ammonia concentrations above 25 ppm gain less weight, convert feed less efficiently, and have higher mortality than birds raised in clean air.

Ammonia also affects the eyes. Birds in high-ammonia houses develop conjunctivitis, a condition sometimes called ammonia burn. The eyes become red, swollen, and watery, and birds may squint or hold their eyes closed. This condition is painful and reduces the birds' ability to find feed and water.

In addition to the direct health effects, high ammonia suppresses the immune system. Birds exposed to ammonia respond less effectively to vaccines and are more susceptible to disease challenges. This means that even if you do not see obvious signs of distress, chronic low-level ammonia exposure can reduce the effectiveness of your vaccination program and make your flock more vulnerable to field challenges.

Economic Costs of Poor Ammonia Control

The economic impact of ammonia goes beyond visible bird suffering. Reduced weight gain means you sell fewer pounds of meat. Higher feed conversion ratios mean you spend more on feed for each pound of gain. Increased mortality means you lose birds you have already invested in. And higher condemnation rates at processing mean you receive less money for the birds you do send to market.

Ventilation costs also factor into the equation. Some growers reduce ventilation to save on heating fuel, only to lose far more money in reduced performance. Research from poultry science institutions has repeatedly shown that the cost of additional heating to maintain adequate ventilation is more than offset by improved bird performance. As a rule of thumb, if you are choosing between spending money on fuel and risking ammonia buildup, spend the money on fuel.

Causes of Ammonia Buildup

Litter Moisture

Litter moisture is the most important controllable factor in ammonia production. When litter moisture rises above 30 percent, bacterial activity increases sharply and ammonia release accelerates. Wet litter also compacts, which reduces its ability to absorb future moisture and creates an environment where anaerobic bacteria thrive. These anaerobic bacteria produce additional ammonia and other noxious gases.

Several factors contribute to wet litter. Drinkers that leak or are adjusted incorrectly are a common source. Nipple drinkers should be maintained at the correct pressure and height so that birds can drink without spilling. Water lines should be checked regularly for leaks, especially at connections and end caps.

The birds themselves add moisture to the litter. A broiler flock produces a significant amount of water in manure, and this moisture must be removed by ventilation. In cold weather, when ventilation is reduced, the moisture from manure accumulates in the litter faster than it can be removed.

Respiratory moisture from the birds also contributes. Birds exhale humid air, and in a tightly closed house with low ventilation, this moisture condenses on walls, ceilings, and litter. Poor insulation and cold surfaces make condensation worse.

Litter Temperature

Ammonia production increases with temperature. Bacterial activity roughly doubles for every 10 degree Celsius increase in temperature within the range normally found in broiler houses. During brooding, when house temperatures are highest, ammonia production is at its peak. This is also the period when chicks are most vulnerable because their respiratory systems are immature and their litter is often moist from the first days of drinking.

The temperature near the litter surface is what matters most for ammonia generation. During brooding, the litter surface can be considerably warmer than the air temperature at human height. This means ammonia can be generated rapidly even when the house thermostat reads moderate temperatures.

Litter pH

Ammonia exists in litter in two forms: ammonium ions, which are relatively harmless and stay in the litter, and ammonia gas, which volatilizes into the air. The balance between these two forms depends on pH. At low pH, most nitrogen stays as ammonium. At high pH, more nitrogen converts to ammonia gas.

Poultry litter naturally becomes alkaline over time because the uric acid in manure is broken down into products that raise pH. This is why litter amendments that lower pH are effective at reducing ammonia. Products containing aluminum sulfate, sodium bisulfate, or similar acidifying agents lower the litter pH and trap nitrogen in the ammonium form.

The effect of pH is dramatic. A small change in pH can produce a large change in ammonia release. This is why pH-lowering litter treatments can bring ammonia down quickly when applied correctly.

Litter Age and Reuse

Litter that has been used for multiple flocks contains more nitrogen and more bacteria than fresh litter. Each flock adds more manure, and the microbial population in the litter becomes more established. Built-up litter therefore has a higher potential for ammonia production than fresh litter.

However, built-up litter also has benefits. It provides insulation, reduces heating costs, and can harbor beneficial microbes that compete with pathogens. The key is managing built-up litter carefully. If you reuse litter, you must be more vigilant about moisture, pH, and ventilation.

Ventilation Shortfalls

Ventilation serves two purposes in a broiler house: controlling temperature and removing moisture and gases. Minimum ventilation is the term used for the ventilation required to control moisture and air quality during cold weather when no cooling is needed. Many growers set minimum ventilation rates too low to save fuel, and ammonia builds up as a result.

The correct minimum ventilation rate depends on the size of the house, the number and weight of birds, the outside temperature, and the moisture content of the litter. As a general guide, a minimum ventilation rate of 0.3 to 0.5 cubic feet per minute per bird is often needed in cold weather, but this varies widely. The best approach is to use ammonia and moisture readings to adjust ventilation rather than relying on a fixed timer setting.

Monitoring Ammonia Levels

Choosing an Ammonia Meter

Accurate ammonia monitoring requires a reliable meter. Several types are available, and they vary in cost, accuracy, and ease of use.

Electrochemical sensors are the most common type sold for poultry house use. They measure ammonia concentration in parts per million and give a digital readout. These meters are portable, relatively affordable, and accurate when calibrated properly. Their main drawback is that the sensors degrade over time and need periodic replacement.

Photoionization detectors are more expensive but can measure a wider range of gases and are very accurate. They are more commonly used by professional consultants and researchers than by individual growers.

Colorimetric tubes use a chemical reaction to measure ammonia. You pump a measured volume of air through a glass tube, and the chemical inside changes color. The length of the color change indicates the ammonia concentration. These tubes are accurate and do not require calibration, but they are single-use and can be tedious for frequent monitoring.

Electronic meters with electrochemical sensors are the best choice for most growers. Buy a meter from a reputable supplier and follow the calibration instructions carefully. Most meters need calibration before each use, and the calibration gas should be fresh and within its expiration date.

Where to Measure

Ammonia concentration varies throughout a broiler house, so single measurements can be misleading. You need to measure at multiple locations to understand the true conditions.

Measure at bird height. For chicks, this means just above the litter surface. For older birds, measure at the height of the birds' heads. This is the air the birds are actually breathing, and it can be significantly different from the air at human standing height.

Measure in the areas most likely to have high ammonia. These include corners, areas near sidewalls, the end of the house opposite the exhaust fans, and areas under brooders. Also measure in the center of the house, where conditions are often better.

Take readings at different times of day. Ammonia levels fluctuate with temperature, ventilation settings, and bird activity. Readings taken in the morning after the house has been closed overnight are often the highest. If you only measure during the day when ventilation is higher, you may miss the worst conditions.

Record your readings in a log. Note the date, time, location, bird age, ventilation settings, and outside temperature. This record helps you identify patterns and evaluate whether your management changes are working.

How Often to Monitor

During the brooding period, check ammonia at least twice daily. This is when ammonia production is highest and chicks are most vulnerable. Check again after any ventilation change, after litter treatment, or whenever you notice birds showing signs of discomfort.

For the rest of the flock, check ammonia daily. More frequent checks are warranted when outside temperatures are low, when litter is wet, or when you are using built-up litter. Some growers check ammonia every time they enter the house, which is a good habit.

Continuous monitoring systems are available and becoming more common in larger operations. These systems use sensors placed throughout the house that send data to a central controller. They can alert you when ammonia exceeds a set threshold and can be integrated with ventilation controllers to automatically increase airflow when ammonia rises. If you are building a new house or upgrading an existing one, consider installing continuous monitoring.

Understanding Your Readings

Ammonia readings below 10 ppm are generally considered acceptable for broilers. At this level, birds show no measurable health or performance effects.

Readings between 10 and 25 ppm are a warning zone. Birds may not show obvious signs of distress, but performance can be affected, especially with prolonged exposure. Take action to reduce ammonia and investigate the cause.

Readings above 25 ppm require immediate action. At this level, birds are being harmed. Increase ventilation, apply litter treatment, and identify the underlying cause. If you cannot bring ammonia down quickly, consider whether the flock is in immediate danger.

Some experts recommend even lower thresholds for chicks during the first week. Chicks have immature respiratory systems and are more sensitive to ammonia. Keeping ammonia below 10 ppm during brooding is a prudent target.

Practical Steps to Reduce Ammonia

Pre-Flock Preparation

Ammonia control starts before the birds arrive. The condition of the litter and the house at placement sets the stage for the entire flock.

If you are reusing litter, remove wet caked litter between flocks. This material is a concentrated source of ammonia and moisture. Remove it thoroughly, especially around drinkers, feeders, and in any areas where moisture accumulates. The amount of cake to remove varies, but removing all visibly wet litter is essential.

After removing cake, consider whether the remaining litter needs treatment. If the litter is dry and has a reasonable pH, you may be able to start the flock without amendment. If the litter has been used for many flocks or has a history of ammonia problems, apply a litter treatment before placement.

Aerate the litter if it is compacted. Tilling or stirring the litter breaks up compaction, allows air to penetrate, and helps dry the litter. This is best done when the litter is dry enough that it does not clump. Aerating wet litter can make the problem worse by bringing moist material to the surface.

Preheat the house before chick placement. A warm house helps dry the litter and reduces the amount of moisture that accumulates in the first days. The goal is to have litter temperature at least 85 degrees Fahrenheit before chicks arrive. Warming the house also reduces the amount of heating needed in the first days, which means you can maintain higher ventilation rates without excessive fuel use.

Run the ventilation system before placement to dry the litter. If the litter is at all damp, run minimum ventilation for a day or two before chicks arrive. This removes moisture from the litter and reduces ammonia production during the critical first days.

Managing Litter Moisture

Keeping litter moisture between 20 and 30 percent is the single most effective way to control ammonia. At this moisture level, bacterial activity is moderate and ammonia production is manageable.

Check litter moisture regularly by feel. Pick up a handful of litter and squeeze it. Dry litter will not form a ball when squeezed. Litter at 25 to 30 percent moisture will form a loose ball that breaks apart easily when touched. Litter above 30 percent will form a tight ball that holds its shape. Litter that feels wet or sticky is too wet and needs immediate attention.

If litter becomes too wet, increase ventilation to remove moisture. In cold weather, this means running minimum ventilation for longer periods or more frequently. You may need to add supplemental heat to maintain temperature while increasing ventilation.

Fix leaks immediately. Check drinker lines daily for drips and leaks. Adjust nipple drinker pressure according to the manufacturer's recommendations and the age of the birds. As birds grow, raise the drinker lines so that birds drink at a natural angle without spilling.

Monitor drinker operation closely during the first week. Chicks are small and may struggle to trigger nipples, causing water to drip. Some growers use supplemental drinkers for the first few days to reduce spillage. If you use supplemental drinkers, remove them once chicks have learned to use the nipples.

Ventilation Strategies

Ventilation is your primary tool for removing ammonia from the house. Even with excellent litter management, some ammonia will be produced, and ventilation is what removes it.

Run minimum ventilation continuously during cold weather. The goal is to remove moisture and gases while conserving heat. Most modern controllers can be set to run fans on a timer cycle, such as 30 seconds on and 90 seconds off. The correct cycle depends on the house, the birds, and the conditions.

Use ammonia readings to adjust ventilation. If ammonia is above 10 ppm, increase ventilation. If ammonia is below 5 ppm and litter moisture is good, you may be able to reduce ventilation slightly to save fuel. But be cautious about reducing ventilation too much, as conditions can change quickly.

Pay attention to air distribution. Ventilation only works if fresh air reaches all parts of the house. Check that air inlets are open and adjusted correctly. In cold weather, incoming air should be directed toward the ceiling so it warms before dropping to bird level. Cold air falling directly on birds causes chilling and increases moisture production.

Use stirring fans to improve air circulation. Stirring fans mix the air and break up pockets of stale, ammonia-laden air. They are especially useful in large houses and in areas where air tends to stagnate.

Increase ventilation before the house reaches dangerous ammonia levels. Do not wait for readings above 25 ppm to act. If ammonia is trending upward, increase ventilation before it becomes a problem.

Litter Amendments

Litter amendments are products applied to the litter to reduce ammonia. They work primarily by lowering litter pH, which traps nitrogen in the ammonium form rather than allowing it to volatilize as ammonia gas. Some products also contain compounds that bind ammonia directly.

The most common litter amendments contain sodium bisulfate or aluminum sulfate. These products are available in granular form and are applied to the litter surface. They are most effective when applied to dry litter and when incorporated into the top layer of litter.

Apply litter amendments before chick placement when you know the litter has high ammonia potential. This is especially important when reusing litter that has a history of ammonia problems. Follow the manufacturer's application rate recommendations. Applying too little will not control ammonia, and applying too much can create dust and irritate birds.

You can also apply litter amendments during the flock if ammonia rises despite good ventilation. Some products are labeled for in-flock application. These are typically applied as a light dusting over the litter surface. Be cautious with in-flock application, as the product can create dust that irritates birds. Apply when birds are on the opposite side of the house or during a period when they are less active.

Reapply litter amendments as needed. The effect of a single application lasts for a variable period depending on litter conditions, bird age, and moisture. Monitor ammonia levels and reapply when readings rise.

Managing Bird Density and Activity

Bird density affects ammonia production because more birds mean more manure and more moisture. Stocking density is often determined by market specifications and house size, but you should be aware of the ammonia implications of high densities.

Bird activity also matters. Active birds stir the litter, which can release ammonia that has been trapped in the litter. This is why ammonia levels often spike when birds are disturbed or when lights are turned on after a dark period. This is not necessarily a problem, as the release of trapped ammonia means the litter is drying and the ammonia can be removed by ventilation.

Encourage activity during the early part of the day when ventilation can be increased. Some growers use feed distribution to encourage birds to move and exercise, which improves litter condition by distributing moisture and manure.

Managing the Brooding Period

The brooding period is the most critical time for ammonia control. Chicks are most sensitive to ammonia, and ammonia production is highest because house temperatures are warm.

Start with clean, dry litter. If you are reusing litter, remove all wet cake and treat the litter if needed. The condition of the litter at placement determines how much ammonia will be produced in the first week.

Maintain higher ventilation rates during brooding than you might think necessary. The cost of heating is real, but the cost of ammonia damage to chicks is higher. A common mistake is to reduce ventilation during the first week to save fuel, then struggle with ammonia problems for the rest of the flock.

Monitor ammonia closely during the first week. Check at least twice daily, and check in multiple locations. Chicks are close to the litter surface, so they are breathing the air that is most affected by ammonia.

Use brooder guards to confine chicks to a smaller area initially. This keeps chicks near heat and feed, but it also concentrates moisture in a smaller area. Make sure ventilation is adequate for the confined area, and expand the brooder area as chicks grow.

Managing Cold Weather

Cold weather is when ammonia problems are most severe. Ventilation is reduced to conserve heat, and the difference between inside and outside temperatures causes moisture to condense on cold surfaces.

Expect ammonia to be higher during cold weather and plan accordingly. Start with the driest possible litter. Use litter amendments proactively. Run ventilation at rates that maintain air quality even if it costs more in fuel.

Pay attention to the weather forecast. When a cold front moves in, ventilation will drop and ammonia will rise. Increase ventilation before the cold arrives so that litter is dry and ammonia is low when you need to reduce airflow.

Use supplemental heat to maintain temperature while ventilating. Propane or other supplemental heating allows you to bring in cold fresh air without dropping house temperature. This is often more economical than the performance losses from ammonia.

Managing Warm Weather

Warm weather usually brings fewer ammonia problems because ventilation rates are high. However, warm weather can create other challenges. High temperatures reduce feed intake and increase water consumption, which can make litter wetter. Warm, humid weather can also make it difficult to remove moisture from the litter.

During warm weather, focus on keeping litter dry. Adjust drinkers to prevent spillage. Use ventilation to remove moisture, especially during the early morning hours when humidity is highest. If litter becomes wet, consider stirring it to promote drying.

Be alert for ammonia spikes during warm weather if ventilation fails. Power outages, fan failures, and controller malfunctions can cause rapid ammonia buildup. Have backup systems and alarm systems in place.

Common Mistakes in Ammonia Control

Relying on Your Nose

The human nose becomes desensitized to ammonia within minutes of exposure. What smells strong when you first enter the house may seem normal after a few minutes. This adaptation means you cannot judge ammonia levels by smell. Always use a meter.

Measuring at the Wrong Height

Ammonia is heavier than air and tends to be more concentrated near the litter surface. Measuring at human height can give readings that are much lower than what the birds are breathing. Always measure at bird height.

Taking a Single Reading

Ammonia varies throughout the house. A single reading from one location can miss problem areas. Take multiple readings at multiple locations and times.

Ventilating Only When Ammonia Is High

Reactive ventilation, where you increase airflow only after ammonia reaches dangerous levels, is less effective than proactive ventilation. By the time ammonia is high, birds have already been exposed. Maintain ventilation continuously to keep ammonia low.

Ignoring Litter Moisture

Litter moisture is the root cause of most ammonia problems. Ventilation can remove ammonia, but if the litter is wet, ammonia will continue to be produced. Address litter moisture as the primary problem.

Applying Litter Treatment to Wet Litter

Litter amendments are less effective on wet litter. They need to be incorporated into the litter and work best when the litter is dry enough to allow the product to penetrate. Treat litter when it is dry, not when it is already wet and producing ammonia.

Overlooking Leaky Drinkers

A small leak in a drinker line can wet a significant area of litter over time. Check drinker lines regularly and repair leaks immediately. Pay special attention to line connections, end caps, and regulator valves.

Reducing Ventilation to Save Money

The fuel saved by reducing ventilation is almost always less than the money lost to reduced bird performance. High ammonia reduces weight gain, increases feed conversion, and increases mortality. These costs far exceed heating costs.

Not Keeping Records

Without records, you cannot identify patterns or evaluate the effectiveness of your management changes. Keep a log of ammonia readings, ventilation settings, litter conditions, and bird performance.

Decision Thresholds

Knowing when to take action is critical for effective ammonia control. The following thresholds provide practical guidance for decision making.

Below 10 ppm

This is the target zone. Birds are not being harmed by ammonia. Continue current management practices and monitor regularly to ensure conditions do not deteriorate.

10 to 15 ppm

This is a caution zone. Birds may not show obvious signs of distress, but prolonged exposure can reduce performance. Investigate the cause of the elevated ammonia. Check litter moisture, ventilation settings, and drinker function. Make adjustments to bring ammonia down.

15 to 25 ppm

This is an action zone. Ammonia is at a level where bird performance is likely being affected. Increase ventilation immediately. Check litter moisture and take steps to dry the litter if it is wet. Consider applying a litter amendment. Monitor closely to ensure ammonia comes down.

Above 25 ppm

This is an emergency zone. Birds are being harmed, and immediate action is required. Maximize ventilation even if it means significant heat loss. Apply litter treatment if available. If ammonia cannot be brought down quickly, consider whether the flock is in immediate danger. This level of ammonia requires immediate attention and may warrant consulting a veterinarian or extension specialist.

Persistent High Ammonia Despite Corrective Action

If ammonia remains above 25 ppm despite increased ventilation, litter treatment, and moisture management, there may be a deeper problem. Possibilities include a ventilation system malfunction, a large water leak, or litter that is too wet to treat effectively. Investigate thoroughly and correct the root cause.

Monitoring and Recordkeeping

Good recordkeeping is essential for effective ammonia control. Records help you identify patterns, evaluate management changes, and communicate with advisers.

What to Record

For each ammonia reading, record the date, time, bird age, location in the house, ammonia concentration, and the ventilation settings at the time of the reading. Also record outside temperature, litter moisture, and any treatments applied.

Record ventilation settings, including timer cycles, fan operation, and air inlet positions. This information helps you understand how ventilation changes affect ammonia levels.

Record litter conditions, including moisture, pH if you measure it, and any treatments applied. Note when litter was last changed, caked, or aerated.

Record bird performance data, including mortality, weight gain, and feed conversion. This helps you connect ammonia levels to flock performance.

How to Use Records

Review your records regularly to identify patterns. You may notice that ammonia rises at certain times of day, in certain parts of the house, or under certain weather conditions. Use this information to adjust your management.

Compare ammonia levels between flocks. If one flock had consistently higher ammonia, identify what was different about the management and correct it for the next flock.

Share your records with your veterinarian or extension agent when you need advice. Good records help them diagnose problems and recommend solutions.

Continuous Monitoring Systems

Continuous monitoring systems provide real-time data on ammonia levels throughout the house. These systems typically use electrochemical sensors connected to a central controller. They can be set to alarm when ammonia exceeds a threshold and can be integrated with ventilation controllers to automatically increase airflow.

Continuous monitoring is especially valuable in large houses, in houses with a history of ammonia problems, and during cold weather when conditions can change rapidly. The initial cost of these systems is significant, but many growers find that the improved performance and peace of mind justify the investment.

When to Call a Veterinarian or Extension Agent

Most ammonia problems can be solved with the management practices described in this guide. However, there are situations where professional help is warranted.

Signs of Respiratory Disease

If birds show signs of respiratory disease, such as coughing, sneezing, gasping, or nasal discharge, call a veterinarian. Ammonia exposure damages the respiratory tract and makes birds more susceptible to infections. A veterinarian can diagnose the specific disease and recommend treatment.

Signs of respiratory disease include increased mortality, reduced feed intake, and birds that are huddled or listless. If you see these signs, do not wait. Call a veterinarian promptly.

Ammonia Levels That Do Not Respond to Management

If ammonia remains above 25 ppm despite your best efforts at ventilation, litter management, and treatment, call your extension agent. They can help you identify the cause and recommend solutions. Sometimes the problem is a ventilation system that is not performing correctly, and a trained technician can diagnose the issue.

Unusual Litter Conditions

If the litter becomes extremely wet, develops a foul odor beyond ammonia, or shows unusual characteristics, call your extension agent. These conditions can indicate problems with the water system, the feed, or the birds themselves.

Planning Major Changes

If you are planning to change from fresh litter to built-up litter, install new ventilation equipment, or make other major changes, consult your extension agent first. They can help you plan the change and avoid common pitfalls.

Frequently Asked Questions

What is a safe ammonia level for broilers?

The target is to keep ammonia below 10 ppm at bird height. Levels between 10 and 25 ppm can reduce performance over time, and levels above 25 ppm cause immediate harm. Chicks are more sensitive than older birds, so aim for the lowest levels possible during the first week.

How often should I check ammonia levels in my broiler house?

Check ammonia at least twice daily during brooding and daily for the rest of the flock. Check more often during cold weather, when litter is wet, or when you have made management changes. Check in multiple locations at bird height, and record your readings.

Can I rely on the smell of ammonia to tell me when levels are high?

No. Your nose becomes desensitized to ammonia within minutes, so you cannot judge levels by smell. Always use a calibrated ammonia meter. What smells mild when you first enter the house may be well above safe levels.

What is the fastest way to reduce ammonia in a broiler house?

The fastest way is to increase ventilation to remove ammonia gas and bring in fresh air. Applying a pH-lowering litter amendment can also help by reducing ammonia production at the source. Both actions should be taken together when ammonia is high.

How does litter moisture affect ammonia levels?

Litter moisture is the primary driver of ammonia production. Bacteria that convert uric acid to ammonia need moisture to thrive. When litter moisture rises above 30 percent, ammonia production increases sharply. Keeping litter between 20 and 30 percent moisture is one of the most effective ways to control ammonia.

Should I use fresh litter or built-up litter to control ammonia?

Both systems can work, but they require different management. Fresh litter has low ammonia potential initially but can become a problem if it gets wet. Built-up litter has more nitrogen and bacteria, so it requires more aggressive management of moisture, pH, and ventilation. Many growers successfully use built-up litter by removing wet cake, treating litter, and ventilating properly.

How do litter amendments work?

Litter amendments lower the pH of the litter, which traps nitrogen in the ammonium form rather than allowing it to volatilize as ammonia gas. They are most effective when applied to dry litter and when incorporated into the top layer. Some products also contain compounds that bind ammonia directly.

When should I apply litter treatment?

Apply litter treatment before chick placement when you know the litter has high ammonia potential, such as when reusing litter with a history of ammonia problems. You can also apply during the flock if ammonia rises despite good ventilation. Follow the manufacturer's recommendations for application rates and methods.

Related Farming Guides

This section will be populated with links to related farming guides on broiler management, poultry house ventilation, litter management, and poultry health.

Related Clinical & Scientific Guides

References

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

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