The objective of this study was a data revision concerning ammonia emissions from slatted pig fattener houses, as well as an evaluation of an ammonia emission index. An obtained emission rate of 3 kg NH₃·(fattener·year)^-1 was used for assessing pig fattener farms’ impact on air quality. Maps of ammonia maximum and average concentration were drawn. The model calculation in the net of receptors was performed for three variants of farm scale: 1,000, 5,000, and 10,000 pig fatteners in four regions of northern Poland. Based on the maps of ammonia concentration isolines, the distances of odor nuisances were indicated.