On a volume basis, distillers grains products have become the third most used feedstuff in American production animal diets—following corn and soybean meal. This increased use has occurred in conjunction with the rapidly increasing supply of distillers grains being produced by the dry-grind ethanol production industry. High feed grain and ingredient prices have livestock producers looking at any and all opportunities to lower feed cost. As of early May, per ton prices of DDGS were below 80 percent of the market value of a ton of corn grain. The economic incentive for a livestock or poultry producer to push distillers grains inclusion levels to the highest level possible is substantial. Based on diet cost economics, livestock producers consider a series of questions that have transitioned from: ‘Can we use distillers grains?’ to ‘How much distillers grains can we use?’ to ‘Can we use more distillers grains than that?’ With those thoughts in mind, let’s look at DDGS use in swine; both the economic advantage to the swine producer to use more DDGS and some of the reasons that keep swine producers from using more DDGS.

The cost savings from using higher levels of DDGS in swine grow/finish diets are substantial. DDGS is a source of energy, amino acids and phosphorus for the pig and partially offsets the use of corn grain, soybean meal, and mineral phosphorus in the diet. For a recent pricing scenario, the average cost of the grow/finish diets was about $260 per ton for corn/soymeal diets with no added DDGS. The average feed cost per ton dropped down to about $225 per ton for corn/soymeal diets with 50 percent inclusion of DDGS. In rough numbers, three grow/finish pigs consume about one ton of complete feed. So, $260 - $225 = $35 per ton savings; divided by 3 pigs = $11.67 feed cost savings per pig. With over 1,000 pigs in a typical modern grow/finish group, you can do the math… So, why then is not every pig consuming diets that contain 50 percent DDGS? There are a number of reasons.

Feed Handling Challenges

Two physical characteristics of distillers grains cover most of the handling challenges we hear about:  bulk density and flowability. Bulk density is a predictable characteristic in that adding DDGS to a corn/soy ration results in finished feed that weighs less per cubic foot. This doesn’t sound like a big deal, until you start dealing with bulk feed trucks that hold 19 ton instead of the 20 ton they used to; or, your bulk feed truck driver calls you from a farm site to tell you that the feed bin that always held 12 ton won’t hold the 12 of ton of feed he had on the truck. This causes temporary inconvenience, but usually works itself out with a little better planning and scheduling of feed deliveries. 

Problems with flowability of DDGS or feeds containing DDGS are not as predictable and can have very serious consequences, especially for the hog producer. Occasional problems with DDGS not flowing out of transport vehicles are dealt with in a variety of ways that the industry has developed over the past few years—one example is specially designed rail cars that unload more easily. There are occasional problems with DDGS not flowing out of storage bins at feed mills. This can result in prolonged downtime for the feed mill, or a feed mixing error.

We can also see flowability problems in finished feed containing DDGS at hog farms. The bins, delivery systems and pen feeders can have bridging of the feed occur, resulting in an “out of feed event.” In finisher hogs, these “out of feed events” can result in several pig deaths due to hemorrhagic bowel syndrome (HBS) that can occur after a pig that has been without feed engorges itself when feed becomes available. HBS usually occurs in larger finisher pigs, so the economic losses can be substantial.

Carcass Impacts

Vegetable oils, like the corn oil found in DDGS, tend to be made up of more unsaturated fatty acids than a product like choice white grease. It has been shown that the fatty acid intake of the pig consistently impacts the fatty acid profile of the pig’s body fat. So what? Unsaturated fatty acids result in a “softer” fat in the pig carcass, which results in bacon that doesn’t slice well and sausage products that have less than desirable appearance in the meat case. Hog producers try to offset these effects by reducing the DDGS level to less than 20 percent of the diet the last four weeks of the feeding period. This happens to be the highest daily feed intake period of the pig’s life.

DDGS is fairly high in fiber. Feeding pigs diets that are higher in fiber results in slightly lower carcass yields; and the reduction is more severe as you increase the amount of DDGS in the diet. What does this mean? If you have pigs in a finishing system with a fixed number of days available in the finishing barn, you will be selling lighter pigs. Pigs are priced on a carcass weight basis, so that means you have less income. In some feed-ingredient and hog-carcass price scenarios, this reduction in carcass yield can offset the savings from feeding DDGS.

Phosphorus, Manure Issues

The phosphorus found in corn is bound in a form that is not available to the pig’s digestive process. The fermentation process at the ethanol plant makes much more of the phosphorus biologically available to the pig. At higher DDGS inclusion levels (over 20 percent of the diet) this can reduce or eliminate the need for supplemental phosphorus mineral in the diet. The phosphorus level can become high enough to result in an incorrect calcium/phosphorus ratio which can result in lameness and/or bone breakage problems in the pork processing facility. If the correct phosphorus level of the DDGS is known, the swine feed can be formulated to correct calcium/phosphorus ratios.

The high fiber content of the DDGS results in lower diet digestibility which means more liquid manure is produced. The fiber also results in liquid manure that is more viscous, leading to crusting and pumping challenges. Another aspect of feeding high levels of DDGS is that the pig’s diet ends up significantly higher in crude protein than the pig requires. The physiology of dealing with the extra protein can increase the pig’s water consumption; also increasing the total amount of liquid manure produced.

Most liquid hog manure storage facilities were sized based on corn/soy diets and designed for annual emptying. The extra liquid manure produced results in the manure storage facility filling up sooner than planned. There also may not be cropland available for manure application before crops are harvested.

These are some, but not all, of the issues surrounding higher inclusion rates in swine rations. This should give ethanol producers and distillers grains merchandisers at least some appreciation for the factors that drive pork producers decisions on how much DDGS to put in the diets they feed their pigs. Swine represent a huge market for DDGS both domestically and internationally. DDGS production practices that help minimize the issues discussed here could help maximize the use of DDGS in swine diets.

Author: Harold Tilstra, DVM
National Coproducts Technical Support
Land O’Lakes Purina Feed LLC
(507) 283-4198
Hdtilstra@landolakes.com
www.ddgsnutrition.com


Land O’Lakes Inc. is a national, farmer-owned food and agricultural cooperative that markets dairy-based consumer, foodservice and food ingredient products across the U.S. and provides an extensive line of feed, seed, and crop protection products and services to farmers and ranchers. Internationally, it serves customers with a variety of food and animal feed ingredients and provides agricultural assistance and technical training in more than 25 developing nations.