[Examination of feed and slurry additives for decrease of ammonia emissions in swine housing]

Ammonia emissions from animal farming have negative effects inside and outside of animal housings. Numerous feed or slurry additives are offered to reduce the ammonia emissions from pig keeping. Investigations were carried out to test the effectiveness of a clinoptilotite-containing feed additive named "Klinofeed" on practical farms and in laboratory experiments. Some effects of ammonium retention were seen in the laboratory tests, which also revealed informations on the absorption mechanisms of ammonium ions. The field experiments didn't show any ammonia reducing effect of the additive. It is recommended to develop a standardized procedure of testing the effectivity and usefulness of feed and slurry additives which are manufactured and sold for ammonia reduction purposes. The presented experiment could be a first basis for such a test procedure.