With the increasing number of ethanol plants removing a portion of oil from their dried distillers grains with solubles, researchers at the University of Minnesota and the USDA Agricultural Research Service in Ames, Iowa have developed energy prediction equations to calculate the energy content of reduced-oil DDGS.
Currently, between 60 and 70% of all U.S. ethanol plants are removing a portion of the oil from thin stillage prior to producing DDGS, according to Dr. Gerald Shurson, professor of swine nutrition and management at the University of Minnesota. By the end of this year, an estimated 80% will be doing so.
The increasing amounts of reduced-oil DDGS in the market was causing concerns among pork producers and nutritionists over how to calculate rations, as well as in the ethanol industry struggling to establish prices.
Shurson and Kerr conducted two experiments using DDGS from 15 sources containing a variety of oil levels between 5% and 12%. The researchers found a poor relationship between the crude fat and energy content, leaving them unable to use the crude fat content to accurately predict what the energy value was to pigs. They discovered that the two most accurate predictors of metabolizable energy in DDGS are gross energy and fiber content.
Using that data, the two used a statistical analysis process that allowed them to develop equations based on those predicators. The equations will likely be used most by nutritionists formulating diets for pig producers or feed companies. A chemical analysis from any sample of DDGS is needed to get inputs needed to go into the equations, such as fiber, gross energy, etc. The equations can estimate energy and compare it to a specific reference point like regular DDGS or corn.
The equations developed in the experiment are available on the University of Minnesota website at www.ddgs.umn.edu.
Cheryl Anderson can be reached at Cheryl.email@example.com.
© Copyright 2012 DTN/The Progressive Farmer, A Telvent Brand. All rights reserved.