Calculate releases from poultry and pig farms: examples
Change of poultry type or number reared
Use this formula to calculate release when the number and/or type of animal you reared changed during the year
((N x F) x M/12) + ((n x F) x M⁄12) = emissions in kg
Where:
N = number of livestock
n = new number of livestock
F = relevant emission factor
M = months applicable
Example
A broiler farm has 50,000 birds for the first five months of the year and 100,000 birds for the remaining seven months. The ammonia emission factor for broilers is 0.024. The ammonia calculation would be:
((50,000 x 0.024) x5/12) + ((100,000 x 0.024) x 7/12) = 1900kg
Ammonia releases from poultry
Multiply the number of birds by the relevant emission factor
Example 1 - Poultry broilers
80,000 broiler places x emission factor of 0.024 = release of 1,920kg
Example 2 - Poultry housing with emissions reduction technology
If you have ammonia reduction technology, such as scrubbers on your poultry shed and do not have accurate monitoring data, you should reduce the emission factor you use in your calculation by the amount of reduction that applies in your permit.
For example, a broiler farm with 240,000 birds with air scrubbing technology that reduces emissions by 90% needs to apply a 90% reduction to the calculation.
The emission factor will be 0.024 x 0.1= 0.0024kg per bird per year. The emissions will be 240,000 x 0.0024 = 576kg.
Example 3 - Storing manure within the installation boundary
If manure is stored on site, and within the installation boundary after removal from the housing, ammonia releases from this must also be reported.
The emission factor is 2.68 for laying hen manure and 1.12 for other poultry manure. The result will give you the kg of ammonia release per tonne per year. This is based on the manure being stored for 12 months. You will need to give a best estimation of the tonnage of manure stored over that 12 month period. If it is stored on site for a shorter period of time, then you will need to amend the calculation. Record keeping required under The Water Resources (Control of Agricultural Pollution) (Wales) Regulations 2021 may help to estimate the tonnage and length of time manure was stored on site.
So, if 17 tonnes of manure is removed from the sheds on a belt system and stored in a manure store for 6 months before spreading to land. The calculation would be:
17 tonnes x emission factor of 2.68 = 45.56kg ÷ 12 months = 3.8 x 6 months of storage = 22.78kg for 6 months of storage.
Don’t forget to add all ammonia produced together and record the total on the system. Remember to show your calculations in the Remarks box.
For example, if you have poultry, an ammonia scrubber and store manure on site you will need to combine all three ammonia releases and report one ammonia release along with your workings.
Particulate matter PM10 (dust) releases from poultry
Multiply the number of birds by the relevant emission factor
Example:
An installation with 50,000 layers in cages
(50,000 x emission factor of 0.05) ÷ 3 = 833kg
Remember to add this into both the Particulate matter (PM10) and Particulate Matter – Total boxes and show your calculations in the Remarks box.
Methane releases from poultry
Multiply the number of birds by the relevant emission factor.
Example:
50,000 broilers x emission factor for poultry manure management of 0.078 = 3900kg.
This is less than the 10,000 kg reporting threshold, so you can enter either ‘brt’ or 3,900.
Change of pig type or number reared
Use this formula to calculate release when the number and / or type of animal you rear changed during the year
((N x F) x M/12) + ((n x F) x M/12) = emissions in kg
Where:
N = number of livestock
n = new number of livestock
F = relevant emission factor
M = months applicable
Example:
An installation has 800 sows for the first five months of the year and 1000 sows for the remaining seven months. The ammonia emission factor for sows on straw is 3.29.
The ammonia calculation would be:
((800 x 3.29) x 5/12) + ((1000 x 3.29) x 7/12) = 3016kg
Ammonia releases from pigs
Example - Pig housing
A farm which used places for 800 sows and 1500 finishers on straw in the calendar year
(800 x emission factor of 3.29) + (1500 x emission factor of 1.888)
= total release of 5464kg
If manure or slurry is stored within the boundary of the installation, releases from this need to be added to the housing releases
So, for a 43m2 slurry lagoon without a cover,
add (43 x emission factor of 1.4) = 60.2 kg
Total emission from housing and manure storage = 5464 + 60.2 = 5524.2kg
Methane releases from pigs
You will need to report methane from the pigs themselves (enteric fermentation), and from manure storage.
Example:
An installation with 800 sows
(800 x emission factor for enteric fermentation of 1.5) = 1200kg
Plus
(800 x emission factor for manure management of 3) = 2400kg
Total emission = 3600kg