Dec. 20, 2002
COLUMBIA, Mo. — It’s mid-summer. You’re driving the car on a two-lane highway somewhere in the rural Midwest. The sun has started its descent, and the heat is not bad. You roll down the window, and just beyond the sweet scent of honeysuckle, you whiff the pungent odor of hogs.
There’s no debate that hog barns emit foul odors, but are those odors the source of serious health and environmental concerns? This question has caused a team of researchers from the University of Missouri–Columbia and Purdue University to study the gases and dust that flow from hog barns. Although the study is ongoing, preliminary data shows that spraying soybean oil within hog barns reduces the amount of dust stirred up by pigs and may mitigate odor as well. Research findings also suggest that the aerial emissions – both dust particles and gases such as ammonia, methane and hydrogen sulfide - from hog barns may be significantly less than reported in previous studies.
Amy Millmier, assistant professor in agricultural engineering at MU, is working to measure emissions from swine-finishing buildings, the large barns where pork producers fatten pigs until they are sold at market for processing. The research is the first long-term emissions study of swine-finishing houses, and the information obtained from the project will help the U.S. Environmental Protection Agency determine whether the emissions from swine-finishing operations should be federally regulated.
Twice a week, Millmier drives three hours to a farm near Harris, Mo., to monitor and calibrate equipment in a mobile testing facility built by her collaborators at Purdue. She also evaluates the effectiveness of spraying the soybean oil by comparing a building where oil is sprayed to one that isn’t.
“The data suggests that there is a significant reduction of dust and odor emissions from the building where we have sprayed the oil,” said Millmier. “So far, we have seen a 35 percent reduction in odor and more than 60 percent reduction in dust from the treated barn.”
Previous studies on swine-finishing operations have been limited in terms of time and testing conditions. For example, short-term studies of emissions have captured the level of aerial emissions from barns full of hogs at only one age or during one climate condition. This project is measuring emissions over the entire time a group of hogs spends in a finishing building. During this time, the pigs will grow from 40 pounds to more than 200 pounds and will experience both summer and winter climates, which significantly affect environmental conditions within the buildings.
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