Ammonia Gas Concentration (Poultry Farm)

Poultry House Ammonia Gas: Understanding Ammonia Gas and Solutions

When ammonia gas concentrations increase during the winter, incorrect judgments can lead to unnecessary ventilation increases. This can result in increased heating costs and cold drafts affecting the chickens, leading to various productivity and environmental issues. In addition, some may mistakenly believe that ventilation needs to be increased further during winter if they deem it insufficient, or blame the staff in charge. Even inexperienced veterinarians can make wrong judgments.

Understanding Ammonia Gas: Lighter Than Air

High ammonia gas concentrations in poultry houses can cause stinging eyes and tear production. Often, this is attributed to insufficient ventilation or negligence by the staff in charge. Ammonia gas is lighter than air.

Air Composition: Nitrogen, Oxygen, and Other Elements

**First, let's calculate the weight of air** : (N₂ × 78%) + (O₂ × 21%) + etc. = Air Weight

((14 × 2) × 78%) + (16 × 2) × 21%) + etc. = approximately 29

The weight of air is approximately 29.

Ammonia Gas Weight

Ammonia = NH₃ = 14 + (1 × 3) = 17

The weight of ammonia gas is 17.

Since ammonia gas is lighter than air, it rises. As a result, the chickens may not be affected, and only your eyes might sting.

Methods for Assessing Ammonia Gas Concentration

To accurately assess ammonia gas concentrations in poultry houses during winter, it's crucial to evaluate at chicken eye level. Evaluating at chicken eye level can help save on heating costs during winter and reduce the occurrence of environmental problems caused by ventilation.

Causes of Ammonia Gas Generation

Undigested nitrogen compounds are present in manure. During the decomposition process, urea and other substances are produced. When these substances come into contact with water, ammonia gas is generated.

Urea chemical formula: (NH₂)₂CO
Water chemical formula: H₂O
(NH₂)₂CO + H₂O = 2NH₃ + CO₂
This reaction produces ammonia gas and carbon dioxide.

General Ammonia Gas Concentration Indicators:

• 10 ~ 15ppm: Detectable by smell
• 20ppm: Can lead to respiratory problems
• 25 ~ 35ppm: Causes watery eyes and runny nose
• 50ppm: Causes watery and reddened eyes in chickens
• 60ppm: Inflammation of eyes, bronchi, and lungs
• 75ppm: Chickens exhibit head tremors and restlessness
• High ppm: Severe irritation and tearing

The above gas concentration indicators are indirect methods for measuring ammonia gas concentrations in the field. However, just because your eyes are stinging at your eye level doesn't necessarily mean the same is true for the chickens. You should evaluate ammonia gas concentrations while sitting and observe the chickens. If you determine that the gas concentration is high, immediately increase the minimum ventilation rate.

Note: The explosive range of ammonia gas is 15-28% (vol%). It's unlikely that ammonia gas concentrations in poultry houses during winter will exceed 28%.

Conclusion

I recently read a book called The Stupid Mistakes of Smart Peopleand it reminded me of an incident from my past where I was scolded by my supervisor for complaining about my stinging eyes in a poultry house during winter. Striving for perfect ventilation can lead to increased heating costs. I believe that decisions based on accurate knowledge can help maintain the most efficient environment.