Kristjan Bregendahl, Animal Science, (515) 294-5132, email@example.com
Susan Thompson, Communications Service, (515) 294-0705, firstname.lastname@example.org
IOWA STATE RESEARCH SHOWS INCREASE IN DIETARY FIBER LEADS TO DECREASE IN AMMONIA EMISSIONS IN POULTRY
AMES, Iowa -- The search for ways to reduce odor from large-scale livestock operations continues at Iowa State University. In a recent project, researchers found that increasing dietary fiber in the feed of laying hens can lower manure ammonia emissions by 40 percent per hen without adversely affecting egg production.
The project involved feeding 256 hens one of four types of diets. There was a standard corn-soybean meal control diet, plus three experimental diets that included corn distiller's dried grains with solubles (DDGS), wheat middlings or soybean hulls.
"Research has shown that adding fermentable fiber to pig diets lowers ammonia emission. We wanted to see if the same thing would happen if fiber was added to the diets of laying hens," said Kristjan Bregendahl, assistant professor of poultry nutrition at Iowa State.
All three fiber diets resulted in lower ammonia emissions. Bregendahl said he is particularly interested in the opportunities offered by corn DDGS, a by-product of ethanol production.
"Given the importance of both the egg and ethanol industries in Iowa, I think it is a big deal that we can reduce ammonia emission by 40 percent from laying hens by feeding just 10 percent corn DDGS. The use of corn DDGS to lower ammonia is essentially free, and may even lower feed cost, because it supplies energy and nutrients to the diet," Bregendahl said. "Other ammonia-lowering feed additives can add as much as $8 to $10 per ton of feed."
Hens fed the fiber diets did not excrete more manure than hens fed the control diet, and egg production and egg mass were not affected. Feed consumption did increase by 2 percent for hens fed the corn DDGS or soybean hulls diets, but the researchers found this effect can be remedied by using more accurate energy values for corn DDGS and soybean hulls.
Stacey Roberts, an animal science graduate student, led the research project with Bregendahl's guidance. Other Iowa State researchers collaborating on the project were Hongwei Xin, professor of agricultural and biosystems engineering; Brian Kerr, U.S. Department of Agriculture's Agricultural Research Service and collaborating associate professor of animal science; and James Russell, professor of animal science.
The research results were shared with industry leaders at the ISU Poultry Science Day, the Iowa Egg Symposium and the Midwest Poultry Federation convention.
A manuscript reviewing the project will be submitted to the peer-reviewed Poultry Science this summer. Follow-up studies with corn DDGS are planned.
Financial support for the research came from the Midwest Poultry Federation and Novus International. In-kind contributions came from Rembrandt Enterprises, Rembrandt; Feed Energy Co., Des Moines; and ADM, Des Moines.