Dimo Dimov1, Ivaylo Marinov2, Toncho Penev1, Chonka Miteva1, Zhivka Gergovska2
1 Department of Applied Ecology and Animal Hygiene, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2 Department of Animal Husbandry – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
Dimov, D., Marinov, I., Penev, T., Miteva, Ch., & Gergovska, Zh. (2019).Animal hygienic assessment of air carbon dioxide concentration in semi-open freestall barns for dairy cows. Bulgarian Journal of Agricultural Science, 25(2), 354–362
The objective of this study was to determine the CO2 concentration in the different animal service zones in semi-open freestall barns for dairy cows. The study was conducted in 3 dairy cattle farms, with production buildings with different capacities – two farms for 120 and one farm for 500 cows. The following microclimate parameters were monitored: temperature (°C), relative humidity (RH, %), temperature-humidity index (THI) and speed of airflow (SAF). The average CO2 values in the three buildings surveyed ranged from 434.85 to 635.27 ppm, with a maximum deviation up to 2130 ppm. The highest CO2 concentrations were recorded in the building with the largest capacity – 500 cows. In the building with a capacity of 120 cows, a trend for the lowest CO2 levels and the least variation during the day was reported. In the summer the lowest CO2 values in the air above the stalls – 515.9 ppm were reported and in the winter the highest – 626.2 ppm. Highest CO2 values in the morning and afternoon were recorded in all investigated barns when the animal’s locomotor activity was greatest associated with eating, drinking, and moving (other activities). The correlation between the temperature-humidity index (THI) values and the CO2 values was significant and negative (-0.23). The lowest CO2 concentrations were reported at THI values 68-72.