Odour and greenhouse gas (GHG) emissions were measured on two 3000-sow farrowing
operations to quantify the relative and absolute contributions to odour and greenhouse gas
emissions from hog barns and manure storage structures; to characterize these emissions; and to
develop or validate models which were capable of confidently predicting the dispersion of odour
from hog operations in surrounding communities. The two farrowing operations (Farm A and
Farm B) were built from the same blueprint with slight modifications – Farm A had an extra
quarantine room at the east end of the building. The buildings on both farms were mechanically
ventilated with wall mounted exhaust fans. Manure was stored as liquid in under-floor shallow
gutters and then removed to outdoor earthen manure storage (EMS). The major difference
between the two operations was that Farm A had a two-cell EMS with negative pressure covers
(NPC); whereas Farm B had an open single cell EMS. It was found that odour emission from farrowing rooms was 2 to 3 times higher than that
from gestation rooms on the two farms. The average odour emission rate of the two farms was
22.9 OU/s-m2 (314 OU/s-AU) from farrowing rooms and 9.6 OU/s-m2 (113 OU/s-AU) from
gestation rooms. There was no statistically significant (P>0.05) difference between the two
farms in emission rate from farrowing rooms; however, the emission rate from gestation rooms
on Farm A was significantly (P<0.05) higher than that on Farm B. Outdoor temperature had the most influence on odour emission from building exhaust. Specifically, the odour emission rate at lower temperatures (<14°C) was significantly lower than that in higher temperature ranges (15- 30°C). The open EMS contributed 60% to the total odour emission on Farm B; whereas the NPC EMS contributed only 2% to the total odour emission on Farm A.