In this project, emission factors for ammonia, methane and nitrous oxide are determined based on the measurement of emissions of these gases from selected pigs, poultry and cattle farms and based on emission measurements after application of pig and cattle slurry and digestate with pig slurry and cattle slurry on agricultural land. Furthermore, the effects of different feed rations on methane production by high-yielding dairy cows are compared. In vitro and in vivo experiments evaluate nutritional methods that would lead to a reduction in greenhouse gas production during rumen fermentation.