Poor Air Quality Can Impact Broiler Welfare and Performance
Air quality inside poultry houses influences bird health, welfare, and performance. (Photo by Dr. Ana Fonseca).
Good air quality starts with good management
What happens inside the poultry house can have just as much impact on flock performance as what goes into the feed. While nutrition and disease prevention are essential, maintaining proper environmental conditions is equally important for bird welfare and productivity. Ammonia (NH₃), carbon dioxide (CO₂), temperature, and humidity vary continuously throughout the grow-out period, making ventilation and litter management critical to successful broiler production.
Researchers in Germany used continuous sensor monitoring on commercial broiler farms to evaluate how barn climate affects bird welfare. Their results showed that poor air quality occurred under normal commercial conditions, and gas concentrations frequently exceeded recommended levels. Many of these problems would likely have gone unnoticed without regular monitoring.
Ammonia and carbon dioxide change throughout the flock cycle
Ammonia and carbon dioxide do not follow the same pattern. Carbon dioxide concentrations are usually highest during brooding because of the birds' respiration and heating systems. Ammonia levels tend to increase later in the flock cycle as manure accumulates and litter moisture rises. Because these gases behave differently, monitoring only one of them may not provide a complete picture of barn air quality.
Elevated ammonia concentrations, particularly above 20 ppm, have been associated with a greater occurrence of hock burn and footpad dermatitis. Since excess litter moisture is a major contributor to these conditions, maintaining dry litter and adequate ventilation is essential for protecting bird welfare. Changes in carbon dioxide concentrations were also associated with footpad lesions, plumage soiling, and changes in body weight, indicating that both gases can affect bird welfare and performance.
Litter management plays a major role
Wet litter remains one of the biggest contributors to poor air quality. Water leaks, improper drinker height, and high humidity can create wet areas, especially under drinker lines. Excess moisture promotes ammonia production and increases the risk of footpad problems, breast blisters, skin burns, carcass downgrades, and bacterial
growth.
As birds approach market age, litter pH also tends to increase, creating conditions that favor ammonia release. Maintaining dry litter and minimizing wet spots are important steps to support bird health and improve air quality.
Monitoring allows earlier intervention
Modern poultry houses increasingly use sensors and automated systems to monitor environmental conditions. However, simple and inexpensive tools, such as colorimetric detector tubes, can also provide rapid measurements of ammonia and carbon dioxide.
Continuous monitoring allows producers to identify problems before they affect bird welfare or performance. Researchers found that small adjustments to ventilation alone were not enough to consistently reduce gas concentrations, emphasizing that effective air quality management requires a combination of proper ventilation, litter management, humidity control, and drinker maintenance.
What producers can do
- Check ammonia and carbon dioxide regularly throughout the flock cycle.
- Pay special attention to ventilation during brooding and near market age.
- Maintain proper drinker height and repair leaks promptly.
- Prevent wet litter and excessive humidity.
- Use sensors or simple monitoring tools to identify problems before they affect birds.
Take-home message
Good air quality starts with good management. Because ammonia and carbon dioxide change throughout the flock cycle and are not always obvious, regular monitoring can help producers detect problems early and make management decisions that support bird welfare, flock performance, and overall productivity.
Research Cited:
- Heck, J., E. Rauch, A. Piller, B. Schiller, M. Erhard, P. Schmidt, and H. Louton. 2026. Levels of two pollutant gases, temperature, and relative humidity and their influence on broiler welfare. J. Appl. Poult. Res. 35:100694. doi.org/10.1016/j.japr.2026.100694.
- Fabian, E. E. 2023. Ammonia monitoring in barns using simple instruments. Penn State Extension, Pennsylvania State University, University Park, PA. Accessed July 10, 2026.
