Reducing odour annoyance from livestock farming in Finland

Production units in Finnish livestock production are significantly increasing. This study aimed to answer to the demand for scientifically justified guidelines to assess and reduce odour annoyance. The study includes the determination of the odour load from different livestock farming units and investigations in feasible odour reducing technologies. Ultimately the project aims to the elaboration of lines for placement of large production units. Odour measurement was made at two pig farms of different size and two broiler production units. The investigations included olfactometric emission measurements in three seasons. Odour measurements were complimented with ammonia, humidity and temperature measurements. The project focused on identifying simple and robust measures to diminish the odour load from agricultural sources. The effect of covering slurry tanks and increased stack height with combined air outlets to achieve improved dispersion was also modelled. The emission data for pig production were slightly higher than results obtained in other countries, although in the same order of magnitude. Emission rates are influenced by a range of local factors including feed, manure management, building design and ventilation rate. Certain lack of unanimity in published odour emission data speaks up for the importance of using data obtained in representative national conditions. Finnish agricultural circumstances differ noticeable from those in Central Europe or North America concerning both climate and production methods. The study showed the benefits of covering manure tanks. Decent reduction in the odour load is achievable by simple floating covers. Odour reducing measures had a positive effect on other environmental parameters. A positive relationship between odour, ammonia and methan reduction was found.