To address odour and gas problems generated by livestock facilities, air dispersion models have been used to determine reasonable science-based setback distances between the livestock operations and the neighbouring residences. However, none of the existing models consider diurnal, seasonal and climate variations of odour and gas (ammonia, hydrogen sulphide, carbon dioxide) concentrations and emission rates (OGCER), which may result in great uncertainties in setback distance calculations. Thus, the purpose of this project was to monitor and model diurnal and seasonal OGCER from swine grower/finisher rooms. Specifically, this research was conducted to: 1) characterize diurnal OGCER between two different flooring systems (fully and partially slatted floorings) under three different weather conditions (August, October and February); 2) identify seasonal OGCER over a 12-month measuring period; and 3) develop mathematical models to predict the OGCER. <p>A two-factorial strip-block experiment was designed for measuring diurnal OGCER in two grower/finisher rooms. It was found that: 1) the diurnal OGCER in the fully slatted flooring system was 27.6 to 39.5% higher than that in the partially slatted flooring system; however, no significant differences in the diurnal OGCER were found between the two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odour concentrations and emissions in February (P > 0.05), and 2) significant diurnal variations in the OGCER (except for the odour concentrations and H2S emissions) have been observed in August (P < 0.05); only gas emissions showed significant fluctuation patterns in October (P < 0.05); no significant variations in the OGCER (except for the CO2 concentrations and emissions) were found in February (P > 0.05). <p>A repeated measurement method was used to monitor seasonal OGCER in four grower/finisher rooms over a period of 12 months. It was found that: 1) the seasonal OGCER from the fully slatted flooring system was 2.9 to 40.6% higher than that from the partially slatted flooring system; however, the seasonal OGCER (except for the NH3 concentrations in October, November and January; the CO2 concentrations in August and the CO2 emissions in December) between the two different floors for each measuring month did not differ significantly (P > 0.05); and 2) the seasonal OGCER was significantly affected by the sampling month (P < 0.05), and no specific seasonal pattern was observed. <p> The statistical models developed for each type of the flooring system determined the OGCER based on the room and ambient temperatures, the ventilation rates and the animal units. The predicted results showed good agreement with measured values for most of OGCER (r2: 0.67-0.95). In order to improve odour and gas prediction models, animal activity and dirtiness of pens should be further investigated.

To address odour and gas problems generated by livestock facilities, air dispersion models have been used to determine reasonable science-based setback distances between the livestock operations and the neighbouring residences. However, none of the existing models consider diurnal, seasonal and climate variations of odour and gas (ammonia, hydrogen sulphide, carbon dioxide) concentrations and emission rates (OGCER), which may result in great uncertainties in setback distance calculations. Thus, the purpose of this project was to monitor and model diurnal and seasonal OGCER from swine grower/finisher rooms. Specifically, this research was conducted to: 1) characterize diurnal OGCER between two different flooring systems (fully and partially slatted floorings) under three different weather conditions (August, October and February); 2) identify seasonal OGCER over a 12-month measuring period; and 3) develop mathematical models to predict the OGCER. <p>A two-factorial strip-block experiment was designed for measuring diurnal OGCER in two grower/finisher rooms. It was found that: 1) the diurnal OGCER in the fully slatted flooring system was 27.6 to 39.5% higher than that in the partially slatted flooring system; however, no significant differences in the diurnal OGCER were found between the two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odour concentrations and emissions in February (P > 0.05), and 2) significant diurnal variations in the OGCER (except for the odour concentrations and H2S emissions) have been observed in August (P < 0.05); only gas emissions showed significant fluctuation patterns in October (P < 0.05); no significant variations in the OGCER (except for the CO2 concentrations and emissions) were found in February (P > 0.05). <p>A repeated measurement method was used to monitor seasonal OGCER in four grower/finisher rooms over a period of 12 months. It was found that: 1) the seasonal OGCER from the fully slatted flooring system was 2.9 to 40.6% higher than that from the partially slatted flooring system; however, the seasonal OGCER (except for the NH3 concentrations in October, November and January; the CO2 concentrations in August and the CO2 emissions in December) between the two different floors for each measuring month did not differ significantly (P > 0.05); and 2) the seasonal OGCER was significantly affected by the sampling month (P < 0.05), and no specific seasonal pattern was observed. <p> The statistical models developed for each type of the flooring system determined the OGCER based on the room and ambient temperatures, the ventilation rates and the animal units. The predicted results showed good agreement with measured values for most of OGCER (r2: 0.67-0.95). In order to improve odour and gas prediction models, animal activity and dirtiness of pens should be further investigated.