Odour generates the largest number of complaints with respect to intensive livestock operations, howver the measurement of baseline odour levels is not widely available. This study intended to measure building odour emissions and gain further infromation for the development of odour impact guidelines for the pork production facilities. In order to achieve this two objectives were established: measure odour concentration and emsission from pif nursery facilities and assess the intensity and offensiveness of odour emitted by swine nurseries.

Two mechanically ventilated nurseries were used to measure odour concentration and offensiveness between March and May 1999. Odour threshold values were determined by a dynamic dilution, forced-choice olfactometre. The resultd indicate a relatively low sampling variance, with odour concentration of pit fans ranging from 94-635 OU averaging 190 OU.Outdoor odour concetration levels averaged 23 OU ranging from 7-85 OU. The arthimetic odour emission rate was 53% of the emission rate reported by Heber(1998) for swine finishing barns. While on the building floor area, the geometric mean of building odour emission was 42% of the value measured by Heber (1998) for finishing buildings. It appears that finishing pigs emit about 90% more odours per animal unit and 140% more per unit area than nursery pigs. Manure depth also seemed to positively influence the odour emission rate. Greater manure depths encourage more anaerobic microbial activities which cause production of more odourous gases.