Ammonia emission from organic pig houses determined with local parameters

The objective of this study was to determine the ammonia emissions from houses for growing-finishing pigs with an outside yard. While regular emission measurements are not possible in these open systems another approach was used. Local parameters were measured and used in an existing NH3 emission model to calculate the ammonia emissions. The following local parameters were measured/determined: total urine fouled floor area, total manure area in the manure pit, surface temperature of fouled areas of floor and manure pit, air velocity above fouled floor areas. Parameters pH and NH4-N content were measured by filter absorption of the urine puddles on the floor and the upper layer of the manure in the pit. These measurements were done in 3 pig houses with outside yard and in 2 regular houses, serving as reference. From the results of this study the following was concluded: 1) The floor emission is generally higher in houses with outside yard compared with regular houses, mainly caused by a larger fouled floor area. 2) The emission per m2 pit surface area is significantly lower in houses with outside yard, especially as a result of the lower surface temperature of the manure in the pit. 3) The determination of ammonia emission in houses with outside yards using locally measured parameters provides a clear methodological perspective. Further validation of this method, however, is necessary. Particular attention should be given to what happens in the upper layer of the manure.