Suggested modes of action to reduce
NH3 emission include a direct binding of NH3 and the inhibition of urease activity (e.g. Makkar et al., 1998). The aim of the
present study was to evaluate the effect of two commercial PFAs, varying in their composition and contents of essential
oils, but both containing same amounts of quillaja (Q. saponaria) saponins, on growth performance and emissions of NH3,
methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) in grower-finisher pigs.