Under the experimental conditions, composting did not occur; under practical conditions the solid fraction is generally stored in heaps where composting is likely to occur (Hansen et al., 2006) depending on the level of oxygenation. N2O emissions can represent up 9.8% of the total N in stored cattle and pig farmyard manure (Chadwick et al., 2011). The results from the present study can be considered representative only of the superficial layer of a heap, where the density and level of aeration permit higher loss in the form of NH3 than N2O (Hansen et al., 2006).