Ammonia Emissions from Pigs on Deep Litter Beds and in a Strip Grazing System

ABSTRACT Ammonia emissions were measured with a micrometeorological difference method in a three-year study of systems with sows and fattening pigs raised indoors or in a strip grazing system. The average emission values were 0.37 ± 0.25 and 0.51 ± 0.23 g 100 kg−1 live weight of the pigs in the indoor and on pasture system, respectively. It is concluded that the extent of ammonia emissions is as much related to local conditions in time and environment as to the general design of the production systems. However, the additional emissions from spreading the manure from the indoor system should be taken into account for a relevant comparison. The strip grazing regime seems to be effective for avoiding point loads of ammonia emissions.