Researchers Seeks Ways to Cut Manure Smell

HAYS, Kan. — While it's said that you can take the boy out of the country but not the country out of the boy, researchers are wondering if they can find a way to at least reduce something closely associated with farm life -- the odor from large amounts of livestock manure.

The smell from the big cattle feedlots found in many parts of western Kansas can be exceptionally powerful, which residents of Hays know all too well because Kansas State University's Agricultural Research Center is there.

But a Fort Hays State University professor, two of his students and a beef cattle scientist at the Kansas State center are working on a project to isolate the chemical that causes the strong odor from the manure.

"If our methods work, I think it'll benefit feedlots across the state as well as the rest of the nation," said John Jaeger, beef cattle scientist at the ag research center. "I understand the city of Hays' frustration at the moment. But we can reduce the odor; it's just going to take some time."

When Jaeger arrived at the center in January, he made it his mission to decrease the feedlot's smell. He had begun exploring several methods when he received a call from Ed Olmstead, instructor of chemistry at Fort Hays State.

"It was funny because here we had just made this a main priority here, and about a week later I get a call from Dr. Olmstead who has the same idea," Jaeger said. "It was pretty fortuitous."

Olmstead and two students, seniors Katie Carnes and Heber Chacon-Madrid, proposed taking manure samples from feedlots and searching for the origin of the disagreeable odor.

"We wanted to do something different, something with a lot of impact," Chacon-Madrid said. "This is something that could definitely help out Hays."

Although the two students graduate in May, the research will continue.

The strong odor in Hays results from decomposition of the organic matter, particularly the anaerobic breakdown of proteins by bacteria, something that can be sped up by heat on a sunny day or by high levels of moisture. Certain anaerobic compounds in the manure cause the smell, and the problem for the researchers is determining which compounds are responsible.

"There's actually been over 168 compounds that have been identified by other researchers that contribute to the odor of feedlots," Jaeger said. "Different feedlots can smell for different reasons. There's a lot of reasons out there, so for Dr. Olmstead and his students to be able to tell me what's the most prevalent here is a good first step in reducing that odor."

The research process involves taking coffee can-sized scoops of manure back to the lab, where a syringe-like instrument with a tiny fiber tip is used to absorb the anaerobic compounds being released.

The next step is to place that tip into the valve of a machine that breaks down the odor into its various compounds, which can be identified through a means of specific coding.

So far, the team has found a heavy concentration of butyric acid in the samples.

Carnes said the compound "smells terrible," but it's most likely only part of the manure odor problem.

Jaeger, meanwhile, is working on different ways to reduce anaerobic breakdown.

"I'm still continuing some of the things that we were working on before Olmstead called me," Jaeger said.

Some of these include a more efficient gutter system that keeps standing water, which stimulates anaerobic breakdown, out of the feedlots.

"We're also working on redesigning the pens to divert precipitation away," Jaeger said. "Cattle have been fed here for over a 100 years now. During that time, change in shape has taken place in the pens. Those depressions have developed that hold water, promote anaerobic breakdown and in turn contribute to the smell."

Jaeger also is working to keep pen surfaces hard, compacted and free of uncompacted manure. He said the cattle's diet also might contribute to the smell.

Source: Associated Press

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