sealPurdue News

April 1998

Purdue research could help keep pork producers
out of hot water

WEST LAFAYETTE, Ind. -- Pork producers are under the microscope, with the Environmental Protection Agency, dozens of state environmental agencies and new neighbors who want to see changes in how hogs are raised.

Water quality concerns, urban-rural migration and questions of farm size and structure have put pork production under intense scrutiny, both in Indiana and across the country, as producers, environmentalists, legislators, regulators and researchers try to get a handle on modern pork production.

In Iowa, the No. 1 hog-producing state in the country, people have noted that nothing in the state constitution says farmers have to raise pigs. North Carolina, the nation's second-largest hog-producing state, has a moratorium on new swine farms. Indiana is writing new rules for livestock production and manure management. Georgia, Oklahoma and several other states are debating strict limits on animal agriculture, and it has become a political pigskin in the Illinois gubernatorial race.

U.S. Sen. Tom Harkin, D-Iowa, wants to see national standards for animal waste handling, saying that "the enormous amount of animal waste produced in America constitutes a growing environmental risk." Senate hearings began April 2.

The Environmental Protection Agency announced March 5 a plan for regulating the 6,600 largest animal feeding operations across the country, targeting those in the most sensitive environments first. Animal waste rules for pork and poultry producers will be rewritten by December 2001.

Purdue University animal scientist Alan Sutton, who literally helped write the book on animal waste management, says well-managed operations pose little threat to water quality, regardless of size. "Poorly managed operations, small or large, could have an adverse effect on the environment," he says. Sutton co-chaired a Council for Agricultural Science and Technology task force that wrote "Integrated Animal Waste Management" in 1996.

So how can the pork industry in Indiana and elsewhere survive? It's become a mission statement for Purdue pork researchers: Economically profitable, socially acceptable and environmentally sustainable pork production. They've tackled the concerns on a number of fronts, according to Purdue agricultural engineer Don Jones.

"Some people may say 'water quality,' but they also mean odor, property values, NIMBY (Not In My Backyard), farm size and a number of other hot buttons," Jones says.

Since December, Jones and Sutton have been busy teaching manure management to the state's 3,800 animal producers who hold confined feeding permits. Helping producers meet state regulations -- which include state inspections and on-farm record keeping of manure disposal -- will help keep the industry out of trouble. Producers also fill out a manure management plan for their operations.

"It's nothing a producer shouldn't already be doing," Jones says. "These are good pollution prevention measures that will help producers pay attention. It could even help them save money." He estimates that he and Sutton talked to 1,300 producers at the Purdue Cooperative Extension Service's "Get Legal" meetings.

In addition to providing producer education, Purdue specialists also are studying better methods of manure disposal that also could help producers' bottom-line.

For example, correctly applying manure to corn fields saves money and boosts yields. Substituting swine manure for commercial fertilizer can save producers $25 to $60 per acre and stimulate an additional 10 to 25 bushels per acre of corn, if the farmer uses nitrification inhibitors that help keep the nitrogen available to the crop, Sutton says.

"That works out to a $2 to $5 return on each dollar invested in better manure application practices," Sutton says. He and Jones also have developed computer-based programs to help make manure applications more accurate.

Purdue researchers also are working to take some of the smell out of the manure. Sutton has been manipulating the amino acids and crude protein in pig feed to affect the final product. In feeding trials he reduced sulfur odorous compounds in manure -- the rotten-egg smell -- by more than 63 percent. Ammonia emissions dropped 45 percent in fresh manure, and stored manure had 48 percent less ammonia emissions. Adding 5 percent cellulose to the diet reduced ammonia emission from fresh manure by 49 percent and from stored manure by 73 percent.

Al Heber, an air quality researcher in Purdue's Department of Agricultural and Biological Engineering, is working on techniques that help trap volatile compounds, as well as manure treatments that neutralize the compounds. He and animal scientist John Patterson experimented with air scrubbers that filter the smellier compounds out of the barn air. Heber also has evaluated commercially available manure additives and compounds that either reduce offensive gases or act as a blanket on top of manure and trap the odors beneath it.

Meanwhile, Heber has just equipped a new odor evaluation lab with a $25,000 olfactometer and a gas chromatograph that will help analyze odors both scientifically and subjectively. Using the olfactometer, a panel of trained sniffers will judge the concentration and offensiveness of odors.

But finding the best spot to put the pigs may be the best bet for odor abatement. Heber is looking for funding to adapt a European-devised computer model that projects the impact of a production facility based on pig population, waste handling systems, predominant wind patterns and other variables. Once adapted for Indiana, producers could test various options to reduce the area their operations affect.

Land application of manure can be improved, too. Purdue agricultural engineer Dan Ess and agronomist Steve Hawkins have devised a computer-assisted manure spreader that measures the amount applied and plots it on a geographical information system. Theoretically, the machine could be set to shut off when it runs too close to surface waters or other off-limit areas. The precision manure spreader already has caught the interest of producers who want to do a better job -- and be able to prove it.

Jones and Sutton say there are other things that could probably help: emergency spillways for lagoons, secondary containment areas, improved equipment and facility design. They also have worked to help more producers learn and implement best management practices.

And if producers do all that, Jones says, he would like to see something from the public: "Perspective."

Out of Indiana's 38,000 livestock producers, the Indiana Department of Environmental Management counts an average of 20 spills per year, and most of those do not kill fish or otherwise significantly impair the environment, Jones says.

"That's a failure rate of one out of 1,900 farms per year," Jones says. "Compare that to the number of sewage overflows coming from any major Indiana city in a year. One city reported more than 100 separate spills of raw sewage last year.

"I don't want people to think that means pork facilities are perfect -- they're not. But they don't deserve all the heat. I'm bullish on pork production. We can fix the problems."

Sources: Al Sutton, (765) 494-8012; e-mail,
Don Jones, (765) 494-1178; e-mail,
Al Heber, (765) 494-1214
Dan Ess, (765) 494-6509
Steve Hawkins, (765) 494-8370; e-mail,
Writer: Chris Sigurdson, (765) 494-8415; e-mail,
Purdue News Service: (765) 494-2096; e-mail,

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