Livestock farming, in addition to numerous benefits, has a number of negative effects on the environment, including the emissions of pollutants, incl. odorants, to atmospheric air. The purpose of the work was to characterize the methods used in assessing the emission of odours from breeding facilities and to analyze the odor standards used in the global legal regulations. The values of odour concentrations measured in livestock buildings and the emission values estimated on the basis of emission factors for various types of livestock farming are presented in the paper. The analyses show that the legal system of European countries applies odour standards expressed in European odour units for a specific unit of time per one animal position (ouE/s/animal place). The analysis of odour concentration measurements and calculations of odour emission factors carried out for poultry farms (turkeys and broilers), pig farms and fur farms showed the highest values of odour emissions for a swine farm and the highest calculated odour emission rates for weaners and sows, which is in line with the values of odor emission indicators suggested by the EU.