GAS CONCENCENTRATIONS AND EMISSIONS IN MILK-FED CALF BUILDINGS

Abstract

In livestock production, the air quality inside the buildings is known to have an impact on health and life quality of workers as well as on the animal performance. Milk-fed calf producers are concerned about this, especially during the winter period when the ventilation is reduced. This study was carried out to evaluate the air quality inside milk-fed calf buildings during three periods (winter, spring and summer) to quantify the risk for workers related to air quality. Three farms having different ventilation systems typically found in Quebec (pre-heated hallways, lateral air inlets and chimney fans) were studied. Data measurements included ammonia (NH3), hydrogen sulphide (H2S), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) concentrations, as well as the ambient conditions like temperature, relative humidity and atmospheric pressure. Gas samples were drawn from inside the building to a mobile instrumentation trailer via Teflon tubing. Sample were analysed using a flame ionisation detector (NH3), an electrochemical H2S sensor and a gas chromatograph (CH4, N2O and CO2). Flow rates from the ventilation system were also measured in order to calculate gas emissions. Results show that there is no important problem of air quality inside milk-fed calf building. The average indoor temperature was properly controlled while the relative humidity was higher than recommendations. The ammoniac was the only gas reaching a concentration close to the maximum time-weighted average recommended for human health. A better control of the minimum ventilation rate should rectify both the relative humidity level and the ammonia concentrations.