Ammonia concentration in cow barn under limited air exchange
2019
Vtoryi, V., Federal Scientific Agroengineering Centre VIM, Moscow (Russian Federation) | Vtoryi, S., Federal Scientific Agroengineering Centre VIM, Moscow (Russian Federation) | Ylyin, R., Federal Scientific Agroengineering Centre VIM, Moscow (Russian Federation)
Ammonia is significantly lighter than air and has high water solubility. In terms of the health effect, ammonia belongs to choking and neurotropic agents; under certain concentrations it can cause the pulmonary edema and severe damage to the nervous system of the workers and animals. This establishes the need to monitor the ammonia content in the cow barn air, especially in winter, when additional insulating measures are taken in the cow barns due to the negative outdoor temperatures and when the air exchange with the external environment is sharply reduced. The study was conducted in Leningrad Region of Russia in the operating typical cow barn with the dimensions of 21x72 m for 200 lactating cows with the tied housing system and natural ventilation. The study was based on the instrumental express method using experiment designing, computer registration and data processing. The ammonia concentration and other inside climate parameters at certain points of the barn in a given time interval were measured. The ammonia concentration was found to depend on the air temperature and humidity in the barn, as well as on the external weather conditions, which affected these factors. During the observation period, the outside air temperature ranged from −6.0 ºC to −10.6 ºC, with the relative humidity being 72−84 % and the absolute air humidity being 1.6−2.3 kgE−3•mE−3. At the measurement points inside the barn, the air temperature ranged from 3.2 to 10.4 ºC, with the relative humidity being 72−90 % and the absolute air humidity being 4.5−7.8 kgE−3•mE−3. The ammonia concentration was 2.62−8.92 kg-6•m-3, with the maximum allowable value in Russia being 20 kgE−6•mE−3. This verified the sufficient air exchange in the barn, providing the necessary conditions for animals. With a decrease in temperature and an increase in humidity in the barn, the ammonia concentration dropped owing to the specific ammonia properties. As the study results, the regression models of ammonia concentration were created with 95 % confidence level, depending on the air temperature in the barn.
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