Maximum Permissible NH₃ Limit in Poultry House

Correct Answer: 25 ppm

The maximum permissible limit of ammonia (NH₃) in a poultry house is 25 ppm. Above this level, it causes significant health problems in birds.

Effects of High NH₃ Levels

• Respiratory tract irritation: Damages the epithelial lining, increasing susceptibility to Chronic Respiratory Disease (CRD), caused by Mycoplasma gallisepticum.
• Eye damage (Keratoconjunctivitis): Blindness, eye ulcers.
• Reduced growth and production: Feed intake and egg production decline.
• Wet litter: Ammonia and wet litter go hand-in-hand — wet litter produces more ammonia.

How to Control NH₃ in Poultry Houses

• Ensure adequate ventilation.
• Add superphosphate or hydrated lime to litter at 0.5 kg per 15 sq ft of floor space.
• Turn litter at least once weekly.
• Maintain litter depth at 8–12 inches (deep litter system).