AMMONIA EMISSION AND ITS REDUCTION FROM CUBICLE HOUSES BY FLUSHING

An investigation was started with the purpose of limiting the NH3 emission from free stall dairy houses. NH3 emission was measured in a cubicle house with slatted floors in the alleys by constantly monitoring the ventilation rate and the NH3 concentration in the exhaust air. The emission per cow appeared to be approx. 1.0 kg NH3 per month. The NH3-emission, measured by a Lindvall box, from the slatted floor and the slurry storage beneath the floor was approx. 650 mg NH3.m-2h-1; the emission from a solid concrete floor was slightly lower. Removing the manure by means of a dung scraper hardly decreased emission. However flushing decreased the emission by approx. 70%. After installing a flushing system the NH3 emission and the amount of flushwater were weekly measured at varying pressure, flushing interval and flushing time. The best results were obtained by flushing frequently for short periods. Compared with traditional cubicle houses the NH3 emission could be decreased to approx. 30%; but the amount of slurry was roughly doubled by the flushwater.