DDG/S Production: Present and Future
Matthew L. Gibson, Ph.D.
and Kip Karges, Ph.D.
Dakota Gold Marketing
Dakota Gold Research Association
4506 N. Lewis Ave.
Sioux Falls, SD 57104
(605) 965-6273
MGibson@DakotaGoldMarketing.com
Summary
The recent growth in production of high-quality Distillers Dried Grains with Solubles (DDG/S) has made this a valuable feed resource for swine production. Most of this growth has come from production of fuel ethanol from corn grown in Midwest USA. If care is taken to understand the product, modern DDG/S can be used quite effectively in swine production. Nutrient content and digestibility are, generally, higher than those listed in peer-reviewed literature. Care must be taken to account for product variability and effects on animal production. New technologies in the ethanol production process result in new distillers products – some of which are dramatically different than traditional product.
Introduction
The ethanol industry is experiencing an explosive growth in available product from the dry-grind process. This is due to a myriad of reasons beyond the scope of this report; however, there is a clear culture of increased ethanol production in the USA. Along with this growth in ethanol production is a concomitant growth in production of DDG/S. Further, new process technologies are constantly being implemented by the ethanol industry. Due to this rapid process evolution, little data exists in traditional, peer-reviewed publications that provide “good� nutrient profile data. This paper will review how DDG/S is produced, what are the characteristics of “new� DDG/S, how the “new� DDG/S is currently being used in swine production, and what the future holds for even newer distillers products which are just now coming into the feed market.
The Ethanol Production Process
Modern ethanol production can be described by its ultimate use: either potable or for fuel. Both processes are remarkably similar, in general (Figure 1). Simplistically, whole corn is ground into a meal, water is added, the resulting mash is cooked (to gelatinize the starch), enzymes are added to cleave free glucose from the starch, yeast is added, and the mixture is allowed to ferment. During this fermentation, two main products are formed: ethanol and CO2. The CO2 is (usually) scrubbed and vented to the atmosphere. The fermented mash is distilled to recover the ethanol. The resultant whole stillage is dried into the feed product Dried Distillers Grains with Solubles (DDG/S).
Even though the two processes are, essentially, identical, the ultimate goal of these two industries is widely divergent. For example, the potable ethanol industry is highly concerned with organoleptic characteristics of the end-product – primarily taste. To achieve different taste profiles, the potable distillers use many techniques such as varying the "mash bill" (essentially, the grain mixture), altering fermentation times (and conditions), aging, as well as many others which are both proprietary and beyond the scope of this discussion. The fuel ethanol industry is focused on one goal: conversion of starch into the greatest amount of ethanol, as quickly and as efficiently as possible.
Regardless of the goal of each industry, one thing is clear: differences in the ethanol production process result in differences in the DDG/S produced. Some of these differences will be reviewed later in this paper.
Fuel Ethanol Industry
The current state of the fuel ethanol industry can best be characterized by the phrase "explosive growth." Most of this growth is localized in the upper Midwest. The reasons for this explosive production increase are myriad and beyond the scope of this paper; certainly many market forces play an economic role. However, the uses of ethanol as a fuel are well-documented and summarized elsewhere (Gibson and Karges, 2005).
Other Information Resources
For further insight into the fuel ethanol industry, many excellent resources are available from industry organizations such as: (1) the Renewable Fuels Association (RFA) at www.EthanolRFA.org; (2) the American Coalition for Ethanol (ACE) at www.Ethanol. org; and (3) the National Ethanol Vehicle Coalition (NEVC) at www.E85Fuel.com.
Ethanol Production Processes
Due to the relatively recent availability of feed co-products from the ethanol industry, a short discussion on the various processes and resulting feed products is warranted. The two types of facilities which produce fuel ethanol are "wet-mill" vs "dry-grind" operations. The last wet-mill operation was commissioned in 1995. The entirety of growth experienced since that time has occurred in dry-grind operations.
The significance of this observation (for animal producers) is that the main feed co-product generated from dry-grind production is DDG/S. Thus, the recent growth of dry-grind ethanol has generated a concomitant growth in supply of DDG/S (Figure 2).
Feed Products
In the feed industry, confusion reigns with respect to the products available from corn milling and ethanol production facilities. There are primarily two types of corn processing facilities, currently, in operation. A brief review of the two is necessary to understand the feed products. Both types begin with the whole corn kernel.
Wet-milling corn processors subject the whole corn to a dilute sulfur dioxide "steep" process for several hours. From there, the corn is ground and milled into various fractions – mainly, bran, starch, protein, oil, and others. The main feed products from wet-milling operations are: steep liquor, bran, germ meal, gluten meal, and gluten feed.
Dry-grind ethanol producers basically process the whole kernel through the entire operation. The resulting feed product is primarily DDG/S. In effect, most other feed products – such as Wet Distillers Grains and Corn Condensed Distillers Solubles – are really "products of convenience" from the post-distillation evaporation processes.
Another difference in wet-mills vs dry-grind operations is in the feedstocks used for production. Obviously the wet-millers are using corn to generate corn oil, corn starch, high-fructose corn syrup, etc. However, dry-grind ethanol producers may use any source of starch (such as any of several grains, grits, screenings, etc.) to produce fuel ethanol.
The Association of American Feed Control Officials (AAFCO, 2006) requires the majority grain to be declared on the label of DDG/S. That is, DDG/S resulting from fermentation of a mixture of 49 % grain sorghum and 51 % corn will be labeled exactly the same as DDG/S from 100 % corn fermentation.
As has been observed, DDG/S production has experienced dramatic growth. Further, this growth curve is expected to remain steep for at least the next 5 – 6 years. Despite aggressive predictions, the growth of the market is exceeding those expectations.
For example, the total production of DDG/S for cropyear 2005 – 2006 is certainly expected to exceed 10 million tons; production will be in excess of 1 million tons per month by the 4th quarter. Earlier predictions – though aggressive – showed the production to reach 12 million tons per year in 2008.
Although many alternative uses of DDG/S are being pursued, for all intents and purposes, the stark reality is that almost all DDG/S will be fed to livestock. Thus, market development in all species of livestock will become crucial sooner than later. An understanding of DDG/S nutrition is vital to the continued success of both the ethanol and livestock industries.
Nutrient Considerations
The DDG/S of today is quite different than that produced just a few short years ago. Old "book values" may or may not be appropriate for use in modern swine diets.
As noted, the dry-grind ethanol industry has experienced rapid evolution. Also, as more DDG/S has become available and has received more attention from the feed industry, some producers have made serious investments into improving DDG/S to the point where it is an acceptable feedstuff for all species of livestock (and pets!). And, due to the rapid growth in this industry, there is a tremendous "data void" that needs to be filled in order to effectively use the product.
When polling nutritionists about DDG/S, the biggest concerns today seem to be centered on nutrient quality and product variability as well as physical factors such as flowability. Several factors are notable and should be discussed individually.
Plant-to-Plant Variation
Due to wide variances in technology and processes, DDG/S coming from plants within close proximity to each other may be quite variable. Even DDG/S coming from one plant may be quite variable on a day-to-day basis. A study by Robinson (2004) examined DDG/S from several sources. He clearly demonstrated that DDG/S may vary widely for certain nutrients; even those nutrients with similar mean values may likely have widely divergent variability between sources (Table 1).
Energy Nutrition
Several factors contribute to the differences in ME values. Certainly, the "New" technology product has more energy than "Old" technology product (Tables 2 & 3). The Swine NRC lists the ME content of DDG/S as 3,032 kcal / kg on a Dry Matter Basis (DMB). Both Spiehs, et. al. (1999) and Allee, et. al. (2005) demonstrated a value closer to 3,900. The Allee data is particularly convincing in that his Corn control was determined to have an ME value of 3,864 which almost exactly matches the NRC-listed value of 3,842.
This variability in ME content is likely due to the over-processing of "old" type DDG/S resulting in Maillard reaction products (which tie up available carbohydrates). Also, "old" DDG/S had lower fat levels than "new" DDG/S (approximately 8 % and 11 %, respectively; NRC & DGRA).
Nutritionists should be aware that both types of DDG/S products are still widely available. Also, the ME of the "new-new" DDG (de-branned / de-fatted; Dakota Gold HP) seems to be fairly similar to that of the "new" DDG/S (Table 3). Care should be taken that proper values are used for diet formulation.
Amino Acid Nutrition
Amino acid nutrition of DDG/S for swine has probably received more scrutiny in recent years than all other nutrient factors, combined. Obviously, the cost of amino acid nutrition in the diet is a significant contributor to this effort. However, the aforementioned Maillard reaction – so common in "old" DDG/S – has been overcome, somewhat, with the "new" DDG/S production. Much effort has been expended to demonstrate the effective use of DDG/S as a protein source.
The Swine NRC is particularly conflicted in its treatment of LYS with respect to all distillers products. Although this treatise is not focused on either Dried Distillers Grains (DDG) or on Corn Condensed Distillers Solubles (CCDS) – both, byproducts of the ethanol process – a brief comparison of these products with DDG/S demonstrates the confusing data.
The LYS levels listed for DDG, DDG/S, and CCDS are 0.74 %, 0.62 %, and 0.82 %, respectively. As the DDG/S product is, essentially, a 50:50 combination of DDG and CCDS, it is easy to see that the data are conflicted with respect to these ingredients. Regardless, the level listed for DDG/S is 0.62 %.
As the protein in DDG/S is derived from that in the corn – and given the concentration factor of 3 – it follows that the LYS should follow this 3-fold increase from corn to the resulting DDG/S. However, the listed level (0.62 %) is only 2.4-fold higher than that in corn (0.26 %). Given the severe heat-damage of the "old" process, these data probably do accurately reflect the "old" DDG/S product.
The Swine NRC lists a regression equation for calculating the LYS level in DDG/S with the variables of: a = 0.0090, b = 0.0221, and r = 0.94. Data from DGRA indicate that for one source of DDG/S these variables are approximately: a = 0.97, b = 0, and r = 0. These data are on an As-Fed Basis (AFB).
Further, an examination of these DGRA data demonstrates the LYS in this source of DDG/S is ap proximately 3.7-fold higher than that in corn (0.95 % vs. 0.26 %) – much different than the level listed for the "old" DDG/S.
Another anomalous observation about LYS is with respect to corn protein levels. It is widely known that corn nutrition can vary on a year-to-year basis. Data from the Broin companies indicate a definitive decline in corn protein between the 2004 and 2005 crop-year (Figure 3). However, during this same period, the DGRA showed that LYS did not decrease in one source of DDG/S (Table 4). Obviously, a close examination of DDG/S from any given source is in order to evaluate exact nutrient levels.
Not only is the LYS level confusing, the digestibility can be quite variable. A listing of various studies (Table 5) indicates a Digestibility Coefficient (DC) ranging from a high of 63 % to a low of 0 % – quite a range, indeed.
Color is frequently mentioned as a quick, subjective indicator of DDG/S quality. This is especially true of LYS digestibility. Ergul, et. al. (2003) and Batal, et. al. (2006) demonstrated that Hunter L* and b* scores were highly correlated with LYS digestibility (Table 6). The Ergul study demonstrated that product with a Hunter L* score of 53.8 and a Hunter b* score of 32.9 had a Digestible LYS content of 0.65 whereas product with a Hunter L* score of 41.8 and a Hunter b* score of 42.8 had a Digestible LYS content of 0.38. The Batal study demonstrated that product with a Hunter L* score of 60.3 and a Hunter b* score of 25.9 had a Digestible LYS content of 0.66 whereas product with a Hunter L* score of 50.4 and a Hunter b* score of 7.41 had a Digestible LYS content of 0.18. Although these studies clearly indicate a good correlation of color with LYS digestibility, it must be noted that differences in Hunter scores are not absolute. Obviously, darker product has undergone more extensive Maillard browning.
One problem with determining amino acid digestibility is the long assay period and high associated costs. Typically, data obtained from a chick assay will cost several hundred dollars and will take many weeks. Similar data from a piglet assay will cost several thousand dollars and will take many months. A new in vitro assay (IDEAâ„¢; NOVUS, Intl.) holds some promise for a quick, inexpensive alternative for determining the LYS digestibility in DDG/S. Schasteen, et al. (2005) found a very good predictive relationship in poultry (Figure 4). Obviously, a pig is not a chicken. However, an examination of a similar assay for SBM indicated a good correlation between the two species (Figure 5).
One notable point: when examining the poultry data, LYS digestibility ranged from a low of approximately 59 % to approximately 83 %. The products used in this study were mostly sourced from highquality, "new� DDG/S production.
Phosphorus Availability
Allee and Fent (2005) estimated the P digestibility to be 85 %. He used a Slope Ratio bioavailability assay with mono-sodium phosphate as the control comparison. The variables measured were piglet fibula ash and breaking strength.
Variation in Fat Values
Fat levels will vary along with other nutrients as discussed previously. However, many nutritionists also consider the fat in DDG/S to be identical to corn oil. Analysis indicates this is not so. The fat in DDG/S has lower linoleic acid and higher omega- 3, the iodine value is lower and the FFA content is higher. (Table 7).
Animal Performance
Sow Lactation: Hill, et. al. (2003) compared a control diet (with 5 % Beet Pulp) to a diet containing 15 % DDG/S. There was no difference (P > 0.05) in sow weight change (-6.2 kg vs -8.0 kg), day 18 litter weight (62.9 kg vs 62.3 kg), litter gain during lactation (41.7 kg vs 43.4 kg), or number of pigs weaned (10.9 vs 10.8) for control diet vs DDG/S diet, respectively. Grow / Finish: Cook (2005) fed graded levels (0, 10, 20, and 30 %) of DDG/S to approximately 1,000 head of pigs. Pigs were housed with 26 head per pen and had an initial weight of 42 kg with an average weight of 117 kg when finished.
The source of the DDG/S was from a "new" process ethanol facility. Nutrient values used for formulating rations were provided by the supplier. Most importantly, an adequate number of samples were analyzed to provide accurate means and variance about those means for all necessary nutrients. Further, statistics were applied to determine formulation matrix values. Digestibility values used for ME, LYS, and P were 1550 kcal / lb, 70 %, and 85 %, respectively.
He found no overall difference in ADG, ADFI, or Gain:Feed. Mortality decreased linearly. Carcass Yield decreased linearly, while Lean Yield and Backfat were not different (Figures 6 and 7). Cook concluded that when proper nutrient values are used, DDG/S can be used effectively at moderate levels for growing / finishing swine with few negative effects. Gourley (2005) fed graded levels of DDG/S to approximately 1,000 head of pigs. Pigs were housed with 26 head per pen and had an initial weight of 33 lb with an average weight of 290 lb when finished.
The source of DDG/S was from a "new" process ethanol facility. This one differed from the Cook study in that it was from an even "newer" BPX™ process facility. (More on the BPX™ process later in this paper). As in the Cook study, adequate sample nutrient analysis (with resultant statistical analysis) was provided to determine formulation matrix values. Similar digestibilities were applied for ME, LYS and P.
The Gourley study used a different scheme for determining the DDG/S inclusion rates. In this study, a typical corn-soy diet was formulated and a calculated NDF level was determined. Then, DDG/S was included at increasing levels to raise the NDF by 1.5 % increments. The resulting diets contained 7.3, 14.6, 21.9, and 29.3 % DDG/S. Due to a collection error, no data were reported for the 14.6 % diet.
As in the Cook study, Gourley found no differences for ADG, ADFI, or Pig Weight Sold. There was an improvement in Feed:Gain for the higher DDG/S inclusion rates. There was no difference in Carcass Weight. As in the Cook study, there was a decrease in Carcass Yield with increasing DDG/S, but no difference in Lean Yield. Interestingly, although there was no difference in Lean Yield, there was a non-statistical increase in both studies.
Gourley also took fat samples from the carcasses and analyzed for Iodine Value (IV). There was a statistical increase in IV at the highest DDG/S inclusion rate.
New Technologies
As noted, the production of ethanol in dry-grind facilities is undergoing rapid technological evolution. And, as should be clearly evident at this point, any alteration of the ethanol process will result in changes to the resultant DDG/S. Some new technologies which have recently appeared in the marketplace are of particular note – especially, due to their profound changes on the resulting DDG/S.
BPX™
A new technology which completely revolutionizes ethanol production has recently been introduced. The technology is named BPX™. The process is patented by the Broin Companies. Essentially, the process allows production of ethanol without "cooking" the mash to gelatinize the starch. The changes on the resultant DDG/S – although not completely understood – are profound. The BPX™ product exhibits greatly improved physical characteristics such as higher density and easier pelleting. Most importantly, the product exhibits enhanced flowability.
Bio-Refining
Until recently, all product going into a dry-grind ethanol production facility has essentially become DDG/S through the process. Now, three fully-commercialized dry-grind facilities have implemented true dry-milling operations in front of the ethanol facility. The whole corn is milled into several fractions which can then be directed into several different production streams (Figure 10).
The "endosperm" stream – actually, a "cornstarch- enriched" stream is what ends up in the fermenter. That is, some of the bran and some of the germ – the non-fermentables – are removed from the whole kernel before fermentation. The advantages to ethanol production are fairly obvious. What is less obvious are the changes to the resultant co-product.
The co-product – marketed under the trade name Dakota Gold HP – is actually a true DDG. It has very high levels of protein (and amino acids, obviously) along with lower levels of fat and phosphorus. Research indicates that the energy value is quite good (Table 3). This is probably due to the removal of the bran fraction which dilutes the ME in “normal� DDG/S.
As the corn is milled prior to fermentation, the "germ enriched" fraction also becomes available as a feedstuff for animal production. The product is marketed as Corn Germ Dehydrated (according to the AAFCO definition). As expected this product is high in fat and phosphorus. As the germ fraction contains the most desirable proteins in the corn kernel, the amino acid profile is quite desirable in spite of a fairly low crude protein level. As the product has not been "steeped" (as in a wet-mill), these protein fractions contain all the soluble fractions. Also, as this corn has not been through fermentation, the oil is in its "native" state.
There are two other bio-refining processes currently under development. Quality Technology International is currently building a corn fractionation facility on an existing ethanol plant (Lohrmann, 2006). The process used is known as HydroMilling™ and is, essentially, a wet-mill type process. Although not yet completed, the company is currently advertising a number of products which will be available from this production facility – namely, high-protein type products which will be targeted at the non-ruminant livestock industries.
Renessen is currently building a pilot plant attached to a small ethanol production facility (Jakel, 2006). Although not yet in production, the Renessen process seems to be similar to the dry-milling process previously described and is being marketed alongside a proprietary corn product. The end-products are claimed to be similar to those from the dry-milling process previously described.
"Oil from Syrup"
One final new technology that deserves mention is the "oil from syrup" process. At least two companies are introducing technology to the ethanol industry for removing the oil from the syrup process stream prior to drying into DDG/S. The uses for this oil are obvious: biodiesel, primarily, and feed, secondarily. Although not yet in wide-spread operation, the process is easy to implement and is quite inexpensive to operate. Nutritionists are cautioned to note that the resulting DDG/S will be lower in fat.
Conclusion
The fuel ethanol industry is experiencing explosive growth in both volume and technology. The DDG/S from this production will be fed. Although the swine industry has been slow to adopt the use of DDG/S in the past, there is a tremendous opportunity for exploiting the plentiful resource in the future. Care should be taken to become intimately familiar with the specific product being fed.
References
Allee, G.L., R.W. Fent, and S.X. Fu. 2005 Determination of the metabolizable energy concentration of different corn byproducts of ethanol production. Univ. of MO – Columbia. Dakota Gold Research Assoc. Rept # 0503.
Allee, G.L. and R.W. Fent. 2005. Evaluation of the bioavailability of phosphorus in distiller’s dried grains with solubles (DDGS) when fed to pigs. Univ. of MO – Columbia. Report to Dakota Gold Research Assoc. Rept # 0503.
B&A. 2005. Broin and Associates. Sioux Falls, SD. Internal Report – Unpublished.
Batal, A.B. and N.M. Dale. 2006. True metabolizable energy and amino acid digestibility of distillers dried grains with solubles. J App Poultry Res 15:89.
Cook, D.R., N.D. Paton, and M.L. Gibson. 2005. Effect of dietary level of distillers dried grains with solubles (DDGS) on growth performance, mortality, and carcass characteristics of grow-finish barrows and gilts. Midwest Amer. Soc. Anim. Sci. meeting, Des Moines, IA.
DGRA. 2003, 2004, 2005. Dakota Gold Research Association. Sioux Falls, SD. Internal Reports – Unpublished.
Ergul, T., C. Martinez Amezcua, C. Parsons, B. Walters, J. Brannon, and S.L. Noll. 2003. Amino acid digestibility in corn distillers dried grains with solubles. Poult. Sci. Assoc. meeting, Madison, WI.
Gibson, M.L. and K. Karges. 2005. Overview of the ethanol industry and production of DDG/S: A nutritionist’s perspective. Multi-State Poultry Feeding and Nutrition Conference. May 23 – 25, Indianapolis, IN.
Gourley, G., and J. Lampe. 2005. Effect of distillers dried grains and solubles formulated for % NDF on the growth and carcass performance of pigs. Swine Grafix Enterprises, Webster City, IA. Dakota Gold Research Assoc. Rept # 0507
Hill, G.M., J.E. Link, M.J. Rincker, K.D. Roberson, D.L. Kirkpatrick, and M.L. Gibson. 2005. Corn dried distillers grains with solubles in sow lactation diets. Midwest Amer. Soc. Anim. Sci. meeting, Des Moines, IA.
Jakel, N. 2006. Fractionation of specialty corn for ethanol fermentation and production of high protein DDGS. Distillers Grains Technology Council, May 18 – 19, Louisville, KY.
Lohrmann, T. 2006. Alternative co-products from a new HydroMilling™ fractionation process. Distillers Grains Technology Council, May 18 – 19, Louisville, KY.
NRC – Swine. 1998. Nutrient Requirements of Swine. Tenth Revised Edition. National Academy of Sciences.
Robinson, P.H. 2004. Nutritive value of distillers grains. Dept. of Anim. Sci. Univ. of CA – Davis. Dakota Gold Research Assoc. Rept # 0301
Schasteen, C.S., J. Wu, G. Yi, C. Knight, C. Parsons, J. Li, and D. Li. 2005. True digestibility of amino acids in raw and heat-treated soy products: comparison of values obtained with cannulated pigs, cecectomized roosters and an in vitro IDEA™ Assay. Midwest Amer. Soc. Anim. Sci. meeting, Des Moines, IA.
Spiehs, M.J., G.C. Shurson, and M.H. Whitney. 1999. Energy, nitrogen, and phosphorus digestibility of growing and finishing swine diets containing distiller’s dried grains with solubles. J. Anim. Sci. 77:188 (Suppl. 1).
Whitney, M.H., M.J. Spiehs, G.C. Shurson, and S.K. Baidoo. 1999. Apparent ileal amino acid digestibility of corn distiller’s dried grains with solubles produced from new ethanol plants in Minnesota and South Dakota. J. Anim. Sci. 77:188 (Suppl. 1)
Stein, H.H., C. Pedersen, and M. Boersma. 2004. Amino acid and energy digestibility in ten samples of dried distillers grain with solubles by growing pigs. Report to Dakota Gold Research Assoc.
Stein., H. 2005. Energy and nutrient digestibility of distillers grains from various sources for growing pigs. Distillers Grains Technology Council, May 18 – 19, Louisville, KY.
Table 1. DDG/S Source-to-Source Cariability¹. Robinson, 2004
| Source | ||
|---|---|---|
| Nutrient | Industry-wide | Dakota Gold |
| Crude Protein | 30.1 +/- 2.6 | 30.7 +/- 1.2 |
| Fat | 11.5 +/- 3.5 | 11.9 +/- 0.7 |
| ADICP | 28.9 +/- 11.7 | 8.2 +/- 2.3 |
| Phosphorus | 0.88 +/- 0.14 | 0.70 +/-0.10 |
¹Mean +/- SD
Table 2. ME (kcal/kg) of DDG/S for Swine. Spiehs, et. al. (1999)
| Exp. 1 | Exp. 2 | Mean | |
|---|---|---|---|
| Grower | 4,707 | 2,983 | 3,845 |
| Finisher | 4,191 | 3,428 | 3,810 |
| Mean | 4,449 | 3,206 | 3,828 |
| NRC | 3,032 |
Table 3. ME (kcal/kg) values for Swine. Allee, et. al. (2005).
| Ingredient | NRC | DGRA |
|---|---|---|
| Corn | 3,842 | 3,864 |
| DDG/S | 3,032 | 3,940 |
| Dakota Gold HP | --- | 4,049 |
Table 4. Variation in DDG/S Lysine between Crop Years. DGRA.
| Crop Year | Mean | S.D. | n |
|---|---|---|---|
| 03-04 | 0.96 | 0.20 | >500 |
| 04-05 | 0.94 | 0.12 | >200 |
| 05-06 | 0.95 | 0.13 | >200 |
Table 5. Lysine (%) and Digestibility Coefficients (%) of DDG/S - Various References
| Source; | Total LYS | Digest. Coeff. | Digest. LYS |
|---|---|---|---|
| NRC | .62 | 47 | .29 |
| Old ¹ | .68 | 0 | .00 |
| MN/SD¹ | .83 | 53 | .44 |
| SD - Low Digest.² | .68 | 44 | .30 |
| SD - Hi Digest.² | .85 | 63 | .54 |
¹Whitney, et. al. (1999)
²Stein, et. al. (2004)
Table 6. Hunter Color Sources and Digestible Lysine
| Color | Hunter L* | Hunter b* | Digestible LYS% |
|---|---|---|---|
| Dark¹ | 41.8 | 32.9 | 0.38 |
| Light¹ | 53.8 | 42.8 | 0.65 |
| Dark² | 50.4 | 7.41 | 0.18 |
| Light² | 60.3 | 25.9 | 0.66 |
¹Ergul, et. al. (2003)
²Batal & Dale (2006)
Table 7. Fatty Acid Profiles. NRC &DGRA
| Item | Corn¹ | DGRA/S² |
|---|---|---|
| C16:0 | 11 | 13 |
| C18:1 | 24 | 29 |
| C18:2 | 59 | 51 |
| Ω3 | 0.7 | 2 |
| Ω6 | 58 | 52 |
| Unsat:Sat | 6.5 | 4.6 |
| Iodine Value | 125 | 110 |
| Free Fatty Acids | 0? | 10 |
¹NRC
²DGRA
