Enzyme Technology Boosts DDGS Performance

Enzymes can be used to overcome the nutritional challenges of distillers dried grains with solubles for use in swine and poultry diets.
By MILAN HRUBY | April 14, 2009
The use of distillers dried grains with solubles (DDGS) in animal feed has increased with the growth of the bioethanol industry. Corn DDGS are a potential good source of protein, vitamins and minerals as they contain about three times more nonstarch nutrients than corn. Swine and poultry producers looking to reduce feed costs can consider using feed ingredients, such as DDGS, to stay ahead of tightening economic pressures. However, whilst DDGS is potentially a cost effective and valuable feed ingredient, there are certain anti-nutritional factors which limit its use in swine and poultry feed.

The Nutritional Challenge
While corn DDGS are a potential good source of protein, vitamins and minerals, they are also highly fibrous (see table 1). Insoluble fibers contained in DDGS hold water creating more bulk in the animal's gut, which can reduce feed intake and subsequent growth. These fibers also bind water-soluble nutrients and enclose them, so they are less available for digestion.

DDGS typically contain 0.38 percent to 1.53 percent phytate. Phytate is the principal storage form of phosphorus in many feed ingredients of plant origin. Most of the phosphorus contained within phytate is in a form which cannot be readily digested by swine and poultry. In addition, phytate binds nutrients such as calcium, energy and amino acids. These bound nutrients are resistant to digestion and unavailable to the animal.

Consistency can also be a big problem as the nutrient composition of DDGS can vary from batch to batch and plant to plant. Flowability of the product can also be a challenge during storage in the feedmill.

The Enzyme Solution
Enzymes are widely used in swine and poultry feed today. However, their use in overcoming the nutritional challenges associated with feeding DDGS is relatively new.

Broiler producers looking for lower feed costs with DDGS supplemented with enzymes can save about $12 per metric ton, without risking bird performance, according to the latest research from Danisco Animal Nutrition.

Two trials conducted by Auburn University and Purdue University showed that adding both a new-generation phytase (Phyzyme XP) together with xylanase, amylase and protease enzymes (Avizyme 1502) to corn soy broiler diets containing 10 percent corn DDGS, improved bodyweight gain and feed efficiency. Bodyweight gain was improved by 5 percent to 8 percent and feed conversion improved by up to 11 points (6 percent).

In the trial conducted by Auburn University, the enzyme combination was also added to a lower-cost diet reduced in energy by 80 kilocalories per kilogram (kcals/kg) feed and containing 0.1 percent lower available phosphorus and lower calcium. At 56 days of age, broiler live-weight gain was significantly better (8 percent) and feed conversion numerically improved (4 points) compared with broilers fed a standard corn soy diet containing 10 percent corn DDGS.

A trial conducted by the University of Illinois showed that adding both the new-generation phytase together with a highly effective xylanase (Porzyme 9300) to a corn-soy swine diet containing 20 percent corn DDGS, significantly improved digestible energy by 5.6 percent (175 kcal/kg), ileal amino acid digestibility by about 4.5 percent and increased phosphorus digestibility from 22 percent to 51 percent (see table 2).

The enzyme combinations help breakdown some of the anti-nutrients in diets containing corn and corn DDGS (see figure 1 above).
With feed prices so high, now, more than ever, swine and poultry producers need to exploit technologies available to them to maximize margins. Using enzyme technology, swine and poultry producers have the opportunity to reformulate diets with lower energy, phosphorus and calcium levels and to include some DDGS in their formulations to further reduce feed costs. For example, in the trial conducted at Auburn University, gross feed cost savings of more than $12 per metric ton were achieved.

Milan Hruby, who has an MSc and Ph.D. from the University of Minnesota, is Danisco Animal Nutrition's regional technical services manager for Canada and the U.S.