However, the ammonia emissions during spreading when slurry is injected into the soil can be considered unaffected by separation (Hutching et al., 2001). Thus considering the whole management system and the share of emissions in the different phases reported by Hutchings et al. (2001) and EEA (2013), the mechanical separation can increase the total emissions of 5–10%, 1.5–2% respectively for NH3, and N2O. Instead CH4 emissions can be effectively reduced of 34 and 15% for pig and cattle slurries, respectively.