Nitrous oxide emissions were not significantly affected by separation. IPCC (2006) give default N2O emission factors of 0, 0.005, 0 and 0.005 kg N2O-N kg1 N excreted for liquid/slurry systems without crust formation, with crust formation, anaerobic digesters and solid storage, respectively. In the present study for the pig manures, contrary to IPCC (2006), N2O emissions were observed from untreated slurries and liquid fractions, with the emission during 1 month accounting for 0.1–0.2% of initial TKN. Emission from P_SF was 0.44% of the initial TKN content, in line IPCC (2006). However, N2O emissions from cattle manure were practically negligible, even from the solid fractions.