Ammonia and Your Small Flock of Laying Hens

Ammonia in the air is one of the most common challenges faced by small poultry flocks during the winter. The birds must be housed indoors and ammonia can quickly build up in the chicken shed. Even if the birds go outside on a warm winter day, they may still breathe in high levels of ammonia while they are cooped up at night.

 The ammonia in the chicken shed comes from the microbial breakdown of the droppings in the litter or manure pack. The release of ammonia from the litter or manure pack occurs year round but ammonia only builds due to the limited amount of fresh air that can be brought into the shed at winter.

 The production of ammonia is highest in warm, moist, deep litter. Tilling or breaking open wet litter can temporarily release high levels of ammonia trapped in the moisture in the litter. Warm barn temperatures will increase the amount of ammonia produced.

 To control the ammonia levels, several steps can be taken:        

• Use stoves or lamps to heat the shed so that you can bring in more fresh air without chilling the birds.
   

•  Lower barn temperature to 10°C once the birds are well feathered (after 8 weeks of age for most birds.) The temperature should be lowered by bringing in more fresh air and not by turning off heater.
   

• Add a fresh layer of straw on the litter. The straw acts as a temporary barrier to ammonia release.
   

• Till or fork up the litter if you have sufficient air movement and heat to dry it out. Note that disturbing the litter can greatly increase the ammonia in the barn for the next day. The more regularly you till, the less ammonia released.
   

•  Apply an acid based litter treatment to trap the ammonia in the litter. Only use products approved for use in livestock facilities and follow the manufacturer’s directions.
   

•  Reduce water spillage by adjusting the lip of your trough or bell drinkers to be level with the birds’ backs. If possible, use nipple instead of bell or trough drinkers.
   

 Use water to trap ammonia in the manure. In cage systems with a gutter underneath, you can add water to cover the manure and slow the release of ammonia.
 Remove the manure every three days or litter every week during cold weather.

 Of these measures, bringing in more fresh air and removing the manure or litter regularly are the most effective methods of controlling ammonia.