Abstract: The invention relates to an exhaust system for the treatment of an exhaust gas comprising ammonia in an amount of up to 250 ppm, the system comprising: an exhaust gas inlet; an ammonia storage material arranged to receive an exhaust gas from the exhaust gas inlet; an ammonia oxidation catalyst arranged downstream of a selected portion of the ammonia storage material; and a heating device for heating gas before it passes through the selected portion of the ammonia storage material to release ammonia stored therein for treatment on the ammonia oxidation catalyst, wherein the system is configured so that the selected portion of the ammonia storage material changes over time. The invention further relates to a livestock house comprising the exhaust system and a method of treating an ammonia-containing gas.