The Comfort Slat Mat (CMS) initially has been developed for beef cattle on slatted floors in 2005 and is utilized in Ireland with positive results since then. In The Netherlands this floor is in use in dairy barns since 2007. Between Oct 2009 & June 2010 Urease tests were carried out according to test protocol urease activity MDV. The tests were preformed at the Waiboerhoeve experimental dairy farm of Wageningen UR at Lelystad. After research the Comfort Slat Mat was registered to the RAV-list (BWL2010.30 and 31) by Jan Atsma, scretary of state. The reduction of ammonia emission is based on the rapid discharge of urine into the tank by the unique curved and smooth surface of CSM. Therefore the urease takes place in the tank with very little to none on the floor.