DDGS energy can be predicted from simple chemical analyses

A prediction equation from a recent study offers a good basis for using an accurate energy value for DDGS in poultry diets

Distillers dried grains with solubles (DDGS) is a valuable but widely variable ingredient, mainly due to major differences in processing technology of ethanol production. For example, in a recent study, fifteen samples of DDGS collected from various dry-grind ethanol plants were found to range from 4.98 to 14.29 percent (DM basis) in ether extract (oil) concentration.

Assigning an energy value to DDGS of variable oil concentration is therefore an exercise that requires careful planning, and to this end, a prediction equation has been developed. Using the above fifteen samples, a series of trials were conducted using broiler chicks receiving experimental diets over a 6-day acclimation period, followed by a 48-hour total excreta collection period.

On a DM basis, apparent metabolizable energy (AMEn) of the 15 DDGS samples ranged from 1,975 to 3,634 kcal/kg. Analyses were conducted to determine gross energy, crude protein, ether extract (EE), dry matter, starch, total dietary fiber, neutral detergent fiber, crude fiber (CF), acid detergent fiber and ash content of the DDGS samples. Using data from these experiments, plus data from previous experiments incorporating proximate analysis data of 30 corn co-products, resulted in the following best-fit equation:

      MEn (kcal/kg) = 3,673 – (121.35 × CF) + (51.29 × EE) – (121.08 × ash), P < 0.01; R2 = 0.70

The high statistical relevance of this prediction equation, plus the fact it is based on easily obtainable chemical analyses, give a good basis for using an accurate energy value for DDGS in poultry diets. And although such prediction equations will never be as accurate as running a live animal test, they are definitely far superior to average values copied from tables of nutrient composition. Today, most modern formulation software packages provide for nutrient equations that are built directly into the matrix, eliminating hand calculations and repeated data entries for all nutrients.