Purdue University Students Sniff Livestock Odors for Research

Purdue University students are making some extra cash through a project that might turn some of their classmates' stomachs — by sniffing livestock excrement. Students earn $30 per session as they take whiffs of a variety of smells collected from barns filled with hogs, cows and chickens for odor research being conducted by Albert Heber, a Purdue professor of agricultural and biological engineering.

"Typically they're farm smells — manure, farm waste, hay. The only thing that is good is that we are not smelling it for a long time. It's just a sniff," said civil engineering graduate student Anuj Sharma.

The students' work provides Heber with data for his ongoing research on ways to improve methods for estimating a given livestock farming operation's odor emissions.

Using an olfactometer they place their noses inside, they sniff diluted samples of air that are taken from different locations on farms and diluted to represent the odors that air would have at various distances from the barn.

Heber said the idea is to test different odor-mitigation techniques to see how effective they are. The less diluted the sample needs to be for the odors to be undetectable, the better the method works.

"If it has to be diluted 1,000 times, that's a pretty strong odor," Heber said. "We have had samples in the past that have been over 10,000."

Heber's work has led to a Web site in which people can input variables, such as the type of animal on the farm, the number of animals or how manure is processed, to determine how far the odors will travel.

The information can be used to decide how close a residence can be to a livestock operation and not be affected by the smells.

Heber's paid sniffers said the job isn't as bad as it sounds.

"It gets a little intense, but since I go out and collect a lot of the samples, it's not that bad," said Sam Hanni, a research assistant for Heber. "It's nothing really strong that would bother you."

Luca Magnani, a doctoral student in animal science, said the hogs farms are the worst to smell, but he's used to being around animals, so it doesn't bother him much.

"Grad students are kind of poor. I've done worse than this, he said.

Sallie Fahey, executive director of the Tippecanoe County Area Plan Commission, said having data that shows how nearby residents might be affected could lessen the tension between farmers seeking to build livestock farms and neighbors worried about its smell.

"If it's an area that's a little close to where there has been a development ... that's when it tends to be contentious," Fahey said.