Ammonia Gas Concentration in Chicken Houses: Implications and Solutions
When supervisors observe a chicken house, they often perceive a high concentration of ammonia gas, potentially indicating insufficient ventilation or poor management. Have you, as a supervisor, ever reprimanded your manager for such situations? It's important to note that even veterinarians can make errors in such assessments.
Understanding Ammonia Gas Behavior: Lighter Than Air
Misinterpreting the discomfort experienced by your supervisor—characterized by stinging and watery eyes—as equivalent discomfort for your chickens is misleading.
Composition of Air: Nitrogen, Oxygen, and Other Elements
To calculate its weight: (N2 × 78%) + (O2 × 21%) + etc. = weight of air
((14 × 2) × 78%) + ((16 × 2) × 21%) + etc. = approximately 29
The weight of air is around 29 units.
Weight of Ammonia Gas
Ammonia = NH3
NH3 = 14 + (1 × 3) = 17
The weight of ammonia gas is 17 units.
Due to its lower weight, ammonia rises. As a result, your eyes may sting, while the chickens remain unaffected.
Field Assessment: How to Proceed
To assess the situation in the field, take a seat and conduct the evaluation at the chicken's eye level to ensure their well-being. During the summer, this concern is mitigated as fans run consistently.
Ammonia Gas Presence: Root Causes
The presence of undigested nitrogenous compounds in chicken waste leads to the generation of urea and other substances during decomposition. When these substances come into contact with water, ammonia gas is produced.
Urea Chemical formula: (NH2)2CO
Water Chemical formula: H2O(NH2)2CO + H2O = 2NH3 + CO2
This reaction yields ammonia gas and carbon dioxide.
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| urea-structure |
Common Ammonia Gas Concentration Indicators:
- 10 ~ 15 ppm: Detectably by smell
- 20 ppm: May lead to respiratory issues
- 25 ~ 35 ppm: Watery eyes and runny nose
- 50 ppm: Chickens' eyes become watery and red
- 60 ppm: Inflammation of eyes, bronchi, and lungs
- 75 ppm: Birds exhibit head shaking and signs of anxiety
- Higher ppm: Severe irritation and tearing
This indirect measure is frequently used to gauge ammonia gas levels in the field. However, a distinction must be made between human and chicken reactions. Watery eyes in humans don't necessarily mirror the same discomfort in chickens. If ammonia gas concentration is high at the chicken's eye level, it could pose challenges for human entry. A better phrasing might be: "If your eyes become watery and stinging while assessing at seated level, promptly increase minimum ventilation."
A Note of Caution: Ammonia Gas Explosive Range is 15% ~ 28% (vol %). Adequate ventilation is essential, even if conditions seem acceptable at chicken's eye level.
In Conclusion
This scenario brings to mind a book I read some time ago: "Dumb Mistakes by Smart People." Striving for impeccable ventilation could lead to higher heating costs. As a manager, continuous and vigilant observation is indispensable for addressing multiple challenges concurrently.