Based on the results of the chemical analyses of the present study, mechanical separation can increase N losses during storage. Concerning slurry spreading, Amon et al. (2006) reported much lower NH3 emissions following the surface-application of separated slurry to soil than from untreated slurry. Also Monaco et al., (2012) reported, for surface-application, significantly lower NH3 emissions from the liquid fraction than from unseparated slurry.