Utilization of Distillers Dried Grains
with Solubles (DDGS) in Swine Diets

Ethanol production in the United States has grown dramatically during the past five years. In July 2005, the U.S. government passed the Energy Security Act, H.R. 6, which contains provisions that will double America?s use of clean burning, renewable fuels such as ethanol. Passage of the Energy Security Act is expected to further accelerate the growth of the cereal grain-based ethanol industry. The three main co-products derived from ethanol production include:

• Distillers grains

• Distillers grains with solubles

• Condensed distillers solubles

These co-products can be either "wet" or "dried" depending on the manufacturing process. Distillers dried grains with solubles (DDGS) is the primary co-product of ethanol production that is commonly used in the swine industry. DDGS utilization in swine diets is expected to grow rapidly because of its improved quality and increased availability. Approximately seven million metric tons of DDGS was produced in 2005. Some experts predict that DDGS production will reach 10 to 14 million metric tons by 2008.

DDGS Nutrient Content and Variability
Corn is two-thirds starch. During the fermentation processes, corn starch is converted to ethanol. As the starch in corn is converted to ethanol, the remaining nutrients become concentrated, resulting in approximately triple the nutrient concentration compared to corn grain. Nutrient content of DDGS can vary significantly by source.

Table 1 shows average nutrient values, the coefficient of variation (CV), and the range of these values for corn DDGS from 32 U.S. sources. Nutrient digestibility of DDGS also varies by source. Research data from South Dakota State University (2004) have shown that apparent ileal digestibility (AID) coefficients of DDGS varied from 58 to 80% for protein, 50 to 76% for lysine, and 31 to 50% for crude fiber among four ethanol plants located in South Dakota and Minnesota. ADM Research (trial S04502) measured AID in samples from four DDGS sources.

AID coefficients ranged from 61 to 67% for crude protein, 46 to 53% for lysine, and 25 to 40% for crude fiber for the four DDGS sources. Nutrient digestibility variations were smaller among the four DDGS sources tested in the ADM research than those tested at South Dakota State University. In terms of digestibility, lysine is the most variable amino acid in DDGS (digestibility for each individual amino acid from different sources of DDGS is not presented in this article). Therefore, when producers use DDGS in swine diets, they need to be aware that DDGS nutrient content and digestibility vary among sources.

In addition to variations in nutrient content and digestibility, DDGS color and smell may also vary. Color ranges from light golden to dark brown, and DDGS smell may be sweet to smoky to burnt. DDGS color has been shown to be correlated with nutrient digestibility. Darker color DDGS may have lower nutrient digestibility.

Two major factors may account for variation in DDGS quality:

• Corn nutrient contents vary among corn varieties and geographic growing locations. Nutrient variability of the corn used can have a dramatic effect on the variability of DDGS. DDGS
  from different grains (corn, barley, milo, and wheat) is expected to have different nutrient concentrations and digestibility because of the nutrient concentration differences among
  these grains.

• Manufacturing methods vary among DDGS plants, resulting in variations of nutrient contents and digestibility of DDGS. Type of yeast used, fermenting and distillation efficiency, drying temperature and time, and amount of solubles added back to the dry materials all affect
  DDGS quality.

Recommended Maximum Feeding Levels of DDGS in Swine Diets DDGS can be used in late nursery, grow-finish, gestation, and lactation diets. Based on swine research conducted by ADM Alliance Nutrition and several universities, the recommended maximum inclusion rates for DDGS in swine diets are given in Table 2.

Recommendations in Table 2 assume that DDGS is of high quality and is free of mycotoxins. DDGS is not recommended for nursery pigs weighing less than 15 lb due to its higher fiber content. The higher fiber content also limits the maximum level (5%) that can be used for late nursery pigs (15 to 40 lb body weight). In an ADM nursery study (trial S06102), pigs were fed diets with different levels (0, 3, 6, 12, and 24%) of DDGS from 18 to 46 lb body weight. Pigs fed up to 6% DDGS had daily gain and feed efficiency similar to those fed diets without DDGS. However, feeding 12% or 24% DDGS depressed feed intake and daily gain. Although the maximum recommended inclusion level of DDGS in finishing diets is 20%, 10% DDGS is the practical amount to use in most grow-finish swine diets. This is because:

• 20% DDGS has been shown to negatively affect performance in a limited number
  of swine studies

• More than 20% DDGS may reduce belly firmness and cause soft pork fat in carcasses because DDGS contains high level of fat (approximately 10%), and a large portion of that fat is composed of polyunsaturated fatty acids

• 20% or more DDGS may reduce carcass yield

One study conducted at the University of Minnesota evaluated previously recommended maximum inclusion rates of DDGS in gestation (50%) and lactation (20%) diets for sows through two reproductive cycles. Sows fed the DDGS diets weaned more pigs per litter during the second reproductive cycle compared to sows fed the control corn-soybean meal diets. This improvement in weaned litter size is similar to the litter size response observed in other studies where sows were fed high-fiber diets. It is unknown if this response can be obtained when feeding gestation and lactation diets containing lower levels of DDGS. Based upon the results of this experiment, up to 50% DDGS can be effectively used in gestation diets and up to 20% DDGS can be used in lactation diets when diets are formulated on a digestible amino acid basis, and DDGS is free of mycotoxin contamination. Mycotoxins have the greatest negative effects on reproduction, so extra care must be taken when using DDGS in sow diets.

DDGS Impact on Gut Health and Manure Odor
Swine producers have reported less problems with ileitis, hemorrhagic bowel syndrome, and manure odor when 10-20% DDGS was included in grow-finish diets. Controlled studies from University of Minnesota indicated there may be some benefit from adding 20% DDGS to grow-finish diets when confronted with a Lawsonia infection; however, University of Minnesota results have been inconsistent. The reason pigs had fewer intestinal lesions caused by ileitis may be attributed to the high insoluble fiber content (42%) of DDGS and/or the presence of compounds with nutraceutical properties in DDGS. A published grow-finish study using 1,040 pigs demonstrated that when dietary DDGS inclusion levels increased from 0, 10, 20, to 30%, there was a linear decrease in mortality percentage (6.0, 2.8, 2.4, and 1.6%, respectively), indicating DDGS may have value in a health challenged system.

A recent poultry study from Iowa State University indicated that feeding DDGS might help control manure odor. Increasing dietary fiber by including DDGS in laying hen diets lowered manure ammonia emissions by 40% without adversely affecting egg production. Additional research is still needed to help evaluate whether DDGS has beneficial effects on gut health and manure odor.

DDGS Swine Feeding Precautions

1. Quality - Quality variation exists among DDGS suppliers and among different batches from the same supplier. This variation includes nutritive values, particle size, and extent of heat damage and color. Analyze DDGS nutrient content prior to using. If laboratory analysis is not possible, ask the supplier to provide the nutrient range of its product over the last few months and use these nutrient levels to formulate swine diets. It is risky to use DDGS in swine diets without knowing the specific nutrient contents of DDGS.

2. Storage - DDGS contain relatively high levels of fat and polyunsaturated fatty acids, which may be subject to rancidity. On the other hand, corn oil contained in DDGS is high in antioxidants, and DDGS pH is relatively low (less than 5), which help extend shelf life of DDGS. As a result, it is suggested that DDGS storage in the winter not exceed six months and no more than two months in summer. Due to its high fat content, DDGS flowability through bulk bins may be a potential concern in some swine operations.

3. Addition of supplemental amino acids - While DDGS contain relatively high level of protein, the amounts of lysine and other amino acids are not very high or well balanced. Pigs require amino acids, not protein, so swine diets with DDGS need to be supplemented with correct amounts of lysine HCl and other amino acids to meet their amino acid requirements. Because of digestibility variations among DDGS sources, it is strongly recommended to formulate the DDGS diets on a digestible amino acid basis rather than total amino acid basis. Data from University of Minnesota indicate that up to 20% DDGS can be used in grow-finish diets if diets are formulated on a digestible lysine (amino acid) basis. However, if diets are formulated on a total lysine (amino acid) basis, no more than 10% DDGS should be used because of concerns of sub-optimal amino acid balance. Addition of supplemental amino acids to DDGS diets will also help decrease nitrogen excretion associated with the relatively high protein content of DDGS.

4. Phosphorus - Phosphorus (P) in DDGS is higher than that in corn (0.75% vs. 0.25%) and has been shown to be more available than phosphorus in corn. This means incorporating DDGS into typical corn-SBM diets may help reduce the need to supplement inorganic phosphorus and help reduce phosphorus excretion in manure.

5. Mycotoxins - Corn is susceptible to molds that can produce mycotoxins prior to harvest as well as during storage. If corn containing mycotoxins is used for ethanol production, the mycotoxins will be present in the DDGS as they are not destroyed during the fermentation process. These mycotoxins will be more concentrated in DDGS (two to three times higher than the initial concentration in corn). Most ethanol plants monitor corn mycotoxin levels in an attempt to control the presence of mycotoxins in DDGS. Specific assay procedures are needed for specific mycotoxin analysis of DDGS samples. If ELISA test kits are used on DDGS, false positives often occur and are invalid for most mycotoxins. The ELISA test kits are only valid for measurement of vomitoxin (deoxynivalenol) and fumonisin in DDGS. High performance liquid chromatography (HPLC) and thin layer chromatography (TLC) methods are acceptable for measuring most mycotoxins that occur in DDGS.

6. Initial feed intake depression - Research has shown that pigs fed diets containing DDGS at no more than the recommended maximum levels have acceptable overall feed intake after DDGS has been fed for weeks or months. However, feed intake may be depressed during the first few days or weeks as pigs adapt to DDGS diets. This is particularly true for nursery pigs, gestating and lactating sows. To avoid this initial feed intake depression, it is suggested to gradually transition pigs to high DDGS diets by offering low DDGS diets first or blending high DDGS diets with non-DDGS diets if feasible.

Summary
DDGS is a co-product from the ethanol industry. As more DDGS becomes available, it is anticipated that there will be more incentive to increase the inclusion of DDGS in swine diets. DDGS nutrient contents and digestibility vary among ethanol plants and among batches from the same plant. Pork fat quality, carcass yield, and mycotoxin contamination are potential concerns when high levels of DDGS are used in swine diets. The maximum amount of DDGS that can be used in swine diets while still achieving equivalent performance to traditional corn-soy diets (provided diets are formulated on a digestible amino acid and available phosphorus basis) varies based on production phase and the quality of the specific DDGS. Properly formulated diets with the appropriate amounts of DDGS may offer feed cost benefits, without compromising pig performance and carcass traits.

Determining the Cost Savings from Using DDGS in a Swine Grower Diet
Depending on the prices of competing feed ingredients (e.g. corn, soybean meal, and monocalcium phosphate), the use of DDGS will usually reduce feed costs. Adding 200 lb of DDGS and 1.5 lb of lysine HCl per ton of complete feed will replace approximately the following amounts of feed ingredients:

             132 lb corn
               65 lb soybean meal 48%
                4.5 lb monocalcium phosphate (21% P)

Calculate the opportunity savings of using DDGS in swine diets as follows:

Ration additions:
          + DDGS                200 lb x $ _____ price/lb = $ _____
          + Lysine HCl          1.5 lb x $ _____ price/lb = $ _____
                                                               Total A = $ _____
Remove from ration:
           - Corn                                   132 lb x $ _____ price/lb = $ _____
           - Soybean meal 48%               65 lb x $ _____ price/lb = $ _____
           - Monocalcium phosphate       4.5 lb x $ _____ price/lb = $ _____
                                                                                Total S = $ _____

Potential savings:
Total S $___ minus Total A $ ____= $____per ton of complete feed based on using 10% DDGS.

For additional information E-mail: AN_SwineHelp@adm.com
Or call ADM Alliance Nutrition Inc, Customer Service 866-666-7626

ADM Alliance Nutrition, Inc. , a wholly owned subsidiary of the Archer Daniels Midland Company