This report focuses on building odor emissions and ways to control it, as it seems to rank high for frequency, duration and offensiveness of odor. Maintaining cleanliness throughout the building is one method to reduce odor. For new buildings, specific designs may lower emissions: flushing gutters, limited surface gutters or solid manure management systems.
One method suggests confining manure storage within the building, in a single area. The exhaust air from this area will then be put through a biofilter prior to discharge into the outdoors.
Dust particles are also odor carriers. Removing these particles from ventilation air can effectively result in reduced odor emissions. In a preliminary study, odor reductions of 50-90% were seen between the inlet and outlet of the filter when dust removal varied between 45-75%. To reduce dust, regular cleaning and maintenance is necessary, as is oil/water spraying.
Reduction in crude protein content of the diet has the ability to reduce the concentration of selected odorous compounds. It is the cost of this method that makes it more unpopular.
Different techniques have been used to control odor as the air comes out of the building. Biofilters and bioscrubbers or wetscrubbers are some of these technologies, with biofilters having the most potential.
In conclusion, if the barn is kept very clean, the manure is removed as often as possible, an efficient dust control technique is implemented and multiphase feeding programs are used, odor emissions from the building are likely to be maintained at an acceptable level. More techniques, design and methods are being researched all the time.