Emissions of Volatile Organic Compounds from a Dairy Cattle Shed in Japan

To clarify the nature and characteristics of volatile organic compounds (VOCs) emitted from dairy cattle within a cattle shed located in Chiba, Japan, air samples were collected and analyzed for the four seasons in 2017-2018. Thirty-four VOCs were determined by gas chromatography-mass spectrometry and high performance liquid chromatography. In addition, air temperature and relative humidity inside and outside of the shed were monitored during each sampling campaign to estimate the ventilation rate of the shed. The average concentrations of total VOCs (μg m-3) in the shed in each season were 50.5 (spring), 128.4 (summer), 168.8 (autumn), and 199.5 (winter). Ketones were always the most dominant components followed by alcohols and volatile fatty acids (VFAs). The sum of ketones, alcohols, and VFAs accounted for more than 80% of the total VOCs in all seasons. Acetone, 3-pentanone, 1-butanol, and acetic acid were the major components regardless of the season, accounting for more than 60% of the total VOCs. The average emission rates of total VOCs from the shed (μg h-1 kg-1) were calculated to be 623 (spring), 1520 (summer), 585 (autumn) and 469 (winter). The emission rates of almost all the VOCs except alcohols increased exponentially with increase of air temperature in the shed. The ranges of the emission rates for each class of chemical (μg h-1 kg-1) were 39-170 (VFAs), 247-913 (ketones), 65-134 (alcohols), 40-122 (phenols), 10-122 (aldehydes), 4.17-22.3 (sulfur compounds), and 0.0067-0.74 (indoles). Furthermore, the annual emissions of VOCs for a single dairy cattle and for the cattle shed were estimated to be 5.5 kg and 44 kg, respectively