<b>By DOUG SCHMITZ<br>
Iowa Correspondent</b></p><p>

AMES, Iowa — According to Iowa State University (ISU) researchers, poultry diets could contain high levels of ethanol by-product as a result of the use of dried distillers grains with solubles (DDGS) as a feed ingredient.<br>
Yet, incorporating ethanol by-products into feed rations is also one way U.S. producers could benefit from the ethanol industry, the researchers concluded.<br>
“Corn DDGS is a co-product from ethanol production (the ethanol is used as an oxygenator in gasoline) and is suitable as a feed ingredient for poultry and livestock,” said Kristjan Bregendahl, ISU assistant professor of poultry nutrition, who led the study, which was conducted by Lane Pineda, a visiting graduate student from Wageningen University in the Netherlands.<br>
“The main feed ingredients in poultry diets are corn and soybean meal, and corn DDGS is really an alternative to those, rather than the other way around,” he added.<br>
Supported by the Hatch Act, State of Iowa funds and the USDA Agricultural Research Service (ARS) in February 2007, the three-month project showed 48 laying hen diets could be formulated with high amounts of corn DDGS without adversely affecting egg production and egg quality.<br>
“We had access to 24 metabolism cages (our main laying hen research barn was occupied by another nutrition study), which each could hold two hens,” Bregendahl said. “I think it’s interesting we could feed a diet with very little corn or starch products in it with such good results.”<br>
Bregendahl said DDGS contain all the nutrients found in the corn kernel, except most of the starch, which has been fermented to ethanol and carbon dioxide. Corn DDGS typically contains about 27 percent crude protein and 10 percent oil, making it suitable as a feed ingredient for poultry and livestock.<br>
Donated to ISU by Southwest Iowa Eggs in Massena, Iowa, the 48 laying hens studied in the project were fed a diet with up to 69 percent corn DDGS.<br>
“In the past, only reports of feeding 15-20 percent corn DDGS have been available, but we showed we can feed as much as we want with no adverse effects on egg production or quality, as long as we have a nutritionally balanced diet,” Bregendahl said.<br>
Four experimental diets of the 48 laying hens consisted of four levels of corn DDGS included in a corn and soybean meal-based diet formulated to meet or exceed the National Research Council nutrient recommendations for laying hens, he added.<br>
Moreover, diets containing 0, 23, 46 and 69 percent corn DDGS were fed for eight weeks after a four-week transition period during which the dietary contents of corn DDGS were gradually increased. Egg production, egg weight and feed consumption were measured weekly, and manure excretion and egg quality were measured after feeding the treatment diets for six weeks.<br>
Bregendahl said egg production decreased as more DDGS was included in the ration; yet egg weight increased, so there was no significant change in overall egg output.<br>
Conversly, feed consumption increased with higher levels of corn DDGS, which led to an increase in nitrogen and dry matter manure excretion.<br>
“However, because the manure application rate on farmland is increasingly determined by phosphorus content, increased nitrogen content adds fertilizer value without affecting the land area needed to apply the manure,” Bregendahl said.<br>
But with an increase in DDGS use, there would also be an increase in research concerned about the efficiency of use for this ingredient by poultry, according to Alex Corzo, assistant professor of poultry science at Mississippi State University.<br>
In addition to the institutions currently evaluating this ingredient, Corzo said an increase in their numbers is expected.
“In the case of Mississippi, our lab and USDA-ARS Poultry Research Unit has initiated research towards the evaluation of this feed ingredient in broiler rations,” he said. “Because of high feed ingredient prices, most integrators will have to include this feed-stuff in their diets.<br>
“While this situation may create some concern due to the bird’s ability to properly utilize this ingredient without negative implications on growth, mortality, feed conversion and yields,” he said, “we have reasons to feel optimistic about improvements in DDGS use by feed mills and by poultry.”<br>
Bregendahl said more research is needed with more hens to investigate potential long-term effects of feeding high levels of corn DDGS.<br>
However, even with the small number of hens in the study, Bregendahl said he’s confident high levels of corn DDGS can be included in layer rations, as long as the nutrient and energy contents of all feed ingredients are known, and diets are formulated on a digestible amino acid basis.<br>
“I would like to confirm these findings with a larger group of hens fed over a longer time period,” he said. “We will also look closer at environmental ramifications as well as potential health effects on the birds.”