When the experimental research work was accomplished, it was determined that the highest rate of ammonia emission in a semi-deep cow-house was above surfaces, polluted with liquefied manure (9.4 g/day.m2 above liquid manure close to a milking parlour); whilst in a cubicle type cow-house – above manure line (8.1 g/day.m2) when manure was moved out by a scraper-type transporter. Minimal rate of ammonia emission was recorded above dungy surfaces with lesser amount of slurry. Using intensive ventilation one can reduce ammonia concentration indoors quickly. However, when intensity of ventilation is increased by 1 m3/h, ammonia emission increases approximately by 3.48 mg/h.m2. Aiming for reduction of atmosphere pollution with ammonia from cow-houses, it is advisable to minimise ventilation rate indoors, but not less than it is necessary for excess moisture removal.