Reducing ammonia emissions in UK dairy housing

Nitrogen is a key component of ammonia. Find out how to control the release of nitrogen from manures in livestock housing and slurry stores so that more can be retained as valuable fertiliser.

Nitrogen in livestock manure

Cattle slurry and farmyard manure (FYM) are made up of Organic N and Ammonium N, which are commonly referred to as readily available nitrogen. Nitrogen in manure is readily available to crops when spread onto land.

The higher the percentage of Total Ammonium N (TAN) the manure contains, the higher the potential of ammonia loss.

Cattle slurry, and the liquid portion of separated cattle slurry, have a high TAN % (typically greater than 30%), so there are high potential ammonia losses compared with cattle FYM, which typically has a 10–15 TAN % depending on the manure to straw ratio.  

The table below shows the key factors that increase or decrease ammonia loss from manures.

Minimises ammonia loss

Increases ammonia loss

Low temperatures

Warm to high temperatures

Reduced air flow over manures

Increased air flow over manures

Reduced to no exposed surface area of manure

Large exposed surface areas of manure

Urine and faeces kept separate

Mixing urine and faeces

Eight ways to reduce ammonia emissions from manures

Carefully managing manures can improve ammonium nitrogen retention and reduce reliance on manufactured fertiliser. 

The techniques that can be used to reduce NH3 emissions from cattle housing are explored below.

Housing periods and frequent removal of manure

Reducing the housed period of cattle and regular removal of manure can both have a positive impact on ammonia emissions.

Housing periods and frequent removal of manure

Cattle house flooring

From automatic floor scrapers to floor construction, find out how different flooring types and systems can reduce ammonia emissions.

Cattle house flooring

Environmental and management techniques

Ammonia emissions can be reduced from cattle housing by addressing slurry pH and temperature, utilising loose housing, scraping and flushing systems, and more.

Environmental and management techniques to reduce ammonia emissions for housed cattle

Emission factors data

Read our emission factors data for livestock, manure storage and land spreading, dairy cow housing, and see a comparison with the Netherlands. 

Emission factors data for cattle and dairy housing

Useful links

Five ways to reduce ammonia emissions for dairy farmers