FEEDLOT ODOR EMISSIONS FOLLOWING HEAVY RAINFALL

There is a need to develop predictive models for odor emissions from c attle feedlots. Surface emissions of odor from a feedlot pen were samp led under standardized aerodynamic conditions using a portable wind tu nnel and tested with a forced-choice, dynamic-dilution olfactometer ov er a five-day period following 64 mm of rain. Pad moisture contents we re monitored. No relationship between odor emission and pad moisture c ontent alone was found even though the emission from the pad was up to 60 times greater under wet than dry conditions. A diurnal variation i n emission rates was observed on some days. A hypothesis explaining th e pattern of odor emission over time is proposed using an understandin g of the kinetics of anaerobic fermentation. If shown correct by furth er research, the hypothesis will provide the basis for a model for the prediction of odor generation.