Trying to cut odor, swine waste treatment process gives extra benefits


CARBONDALE, Ill. – A swine waste treatment process developed at Southern Illinois University Carbondale can remove most traces of Tylosin, a popular animal antibiotic.

“Within hours Tylosin drops to about 20 percent of its original concentration, and within a couple of days it is 90 percent reduced,” said James W. Blackburn, a mechanical engineer who designed the process.

Antibiotic use. Tylosin is popular with hog farmers, not just to treat or forestall disease but as a means for piling the pounds on the porkers as well.

According to a USDA survey of pork producers done in 2000, Tylosin was the most popular growth-promoting drug that year, with 31.3 percent of farmers raising grower/finisher pigs using it for that purpose.

Twenty-five percent of these producers also reported using Tylosin for disease treatment or prevention.

Those using it to promote growth fed it to their pigs for about 73 days. To prevent disease, they added it to their swine feed for about 58 days, and when treating ailments, they used it 39 days.

Treatment system. Blackburn’s treatment system uses a mix of bacteria, high temperatures and air to break down manure.

The original goal was to cut odor, a big concern for hog farmers when the project got off the ground three years ago. It does that and more.

Not only can it get rid of the manure’s stink in less than a day, the process itself produces power that can heat pens or other farm buildings.

And the treated manure, low in phosphorus and high in nitrogen, can substitute for commercial fertilizer with no drop in yields. It was the fertilizer component that led Blackburn to take a look at antibiotic residues.

“In order to be marketed as an ‘organic’ fertilizer, our product would have to be certified, which it couldn’t be if it had high levels of antibiotics in it, so we wanted to see if our process could degrade antibiotics,” he said.

“We looked at Tylosin because it is so widely used and we had a good analytical tool for it already in our lab.

“It turns out Tylosin is very susceptible to the conditions in our process, but the fact that (reduction) happens so fast is very unusual. It’s a clue that it’s not being degraded in a normal biological way.

“We think the Tylosin actually binds to the bits of biochemicals left over during the process. But once it happens, it’s irreversible. We’ve tested that.”

No guarantees. Just because the process works on Tylosin doesn’t mean it will work with all such drugs, Blackburn cautioned.

He plans to test it on two more widely used antibiotics from the tetracycline family within the next year.

In the meantime, he hopes that the Tylosin connection will convince some pork producers to give his system a try, the first step in making the technology commercially available.

“A hog producer might not want to build it just for odor or antibiotic removal or just for the energy or just for the fertilizer, but if you put all that together, it makes an attractive package,” Blackburn said.

Farmers who would like to learn more about installing a free farm-scale model of this treatment system can call Blackburn at 618-453-7008 or e-mail him at


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