| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
ANIMAL NUTRITION |
* Department of Animal and Range Sciences, South Dakota State University, Brookings 57007 and
and
Dakota Gold Research Association, Sioux Falls, SD 57059
 |
Abstract |
|---|
 Top Abstract INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONIMPLICATIONSLITERATURE CITED |
|---|
Key Words: amino acid • digestibility • distillers dried grain with solubles • energy • pig
|
INTRODUCTION |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONIMPLICATIONSLITERATURE CITED |
|---|
; Spiehs et al., 2002). This variability is likely caused by differences in the effectiveness of the fermentation, drying temperatures, or the amounts of solubles that are added to the distillers dried grain.
Because DDGS has also gone through heat treatment, there is a risk that the digestibility of Lys may be reduced in some cases because of Maillard reactions (Cromwell et al., 1993). Apparent ileal digestibilities (AID) of only 27% have been reported for Lys in DDGS, which indicates that some sources of DDGS might have been overheated (Fastinger and Mahan, 2005).
For the swine industry to include DDGS in the feed formulations, it is important that a consistent product is available. Therefore, Broin and Associates (Sioux Falls, SD) have introduced a branded product called Dakota Gold, which is produced at 10 different ethanol plants in the Midwest and has a constant concentration of crude nutrients (i.e., CP, 28.2%; fat, 10.7%; ADF, 11.9%; and NDF, 27.2%). However, it is not known if the product is also consistent in terms of AA and energy digestibility.
Therefore, the objective of the current experiment was to test the hypothesis that DDGS from Dakota Gold has a constant digestibility of energy, CP, and AA in growing pigs regardless of the origin of the samples.
|
MATERIALS AND METHODS |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONIMPLICATIONSLITERATURE CITED |
|---|
. After the surgery, pigs were housed individually in 1.2 x 1.8 m pens in an environmentally controlled room (22°C) and allowed a 2-wk recuperation period before the experiment was initiated. During that period, a standard corn soybean meal-based grower diet (18% CP) was provided. After the recuperation period, pigs were allotted to an 8 x 12 Youden square design (Anderson and McLean, 1974) with 8 periods and 12 animals. Each experimental period lasted 7 d. The experiment was approved by the Institutional Animal Care and Use Committee at South Dakota State University.
Ingredients, Diets, and Feeding
Ten samples of Dakota Gold DDGS were obtained from 10 ethanol plants located in the Midwest (Table 1). All plants produced ethanol from corn. In addition to the 10 sources of DDGS, a sample of corn was obtained from a commercial source.
|
and 3). Ten diets consisted of 1 of the 10 samples of DDGS (66.7%) and cornstarch, sucrose, soybean oil, minerals, and vitamins. In all of these diets, DDGS was the sole source of CP and AA. A corn-based diet (97% corn) and a N-free diet were also formulated. The N-free diet was used to estimate the basal ileal endogenous losses (IAAend) of CP and AA. The only energy-containing ingredients in the N-free diet were cornstarch, soybean oil, and sucrose. These ingredients were included in the N-free diet in quantities that were 3 times those in the diets containing DDGS. In all diets, chromic oxide was included at 0.3% as an inert marker. Vitamins and minerals were included to meet or exceed estimated nutrient requirements for growing pigs (NRC, 1998). Inorganic P in the form of dicalcium phosphate was included in the corn-diet and the N-free diet, but because of the high P-concentration in DDGS, no inorganic P was included in the diets containing DDGS. Limestone was included in all diets to bring the calculated Ca:P ratio to 1.2:1. Because the feed ingredients included in the N-free diet were assumed to contain no K and Mg, these minerals were supplied in the form of potassium carbonate and magnesium oxide, respectively. It was assumed that K and Mg were present in diets containing corn or DDGS in quantities sufficient to meet the requirements of animals.
|
|
). The ME was calculated (NRC, 1998) as 3,081, 3,317, and 3,813 kcal of ME per kg (as-fed basis) in the DDGS diets, the corn diet, and the N-free diet, respectively. The daily allotments of feed were divided into 2 equal meals. Throughout the experiment, pigs were given free access to water from a nipple drinker.
Data and Sample Collection
Pig weights were recorded at the beginning of each period and the amount of feed supplied each day was recorded. The initial 4 d of each period were considered an adaptation period to the diet. Fecal samples were collected (grab-sampling) in the morning of d 5 and d 6 and stored at –20°C until analyzed. Ileal digesta were collected for 10 h on d 6 and d 7. A 225-mL plastic bag was attached to the cannula barrel using a cable tie, and digesta flowing into the bag were collected. Bags were removed whenever they were filled with digesta, or at least every 30 min, and stored at –20°C. Upon the completion of 1 experimental period, animals were deprived of feed overnight, and the following morning a new experimental diet was offered.
Chemical Analysis
At the conclusion of the experiment, ileal samples were thawed, pooled within animal and diet, and a subsample was taken for chemical analysis. A sample of each diet and of each of the samples of DDGS and corn were collected as well. Digesta samples were lyophilized and ground through a 1-mm screen before chemical analysis. The fecal samples were dried in a forced air oven (60°C) and ground before chemical analysis. The feed ingredients, the diets, and the ileal digesta samples were analyzed for DM (procedure 4.1.06, AOAC, 1998) and for CP (procedure 990.03, AOAC, 2000). The fecal samples also were analyzed for DM, and starch was analyzed in all DDGS samples (procedure 996.11; AOAC, 2000). The concentration of P was determined in all the DDGS samples and in the diets (procedure 968.08D, AOAC, 2000). Amino acids were analyzed in DDGS, diets, and ileal samples on a Beckman 6300 Amino Acid Analyzer (Beckman Instruments Corp., Palo Alto, CA) using ninhydrin for postcolumn derivatization and norleucine as the internal standard. Before analysis, samples were hydrolyzed with 6 N HCL for 24 h at 110°C (procedure 4.1.11, alt. 3, AOAC, 1998). Methionine and Cys were determined as Met sulfone and cysteic acid after cold performic acid oxidation overnight before hydrolysis (procedure 4.1.11, alt.1, AOAC, 1998). Tryptophan was determined after NaOH hydrolysis for 22 h at 110°C (procedure 988.15, AOAC, 1995). Chromium concentrations of diets, ileal digesta, and fecal samples were determined after nitric acid-perchloric acid wet ash sample preparation (procedure 990.08, AOAC 2000). The energy concentration in diets, feed ingredients, and fecal samples were determined using bomb calorimetry (Parr Instrument 1563, Moline IL).
Calculations
The AID for AA in the diets containing DDGS or corn was calculated. Because DDGS or corn was the only feed ingredient contributing AA in these diets, these values also represent the digestibility for each of the samples of DDGS or of corn. Eq. [1] was used for these calculations:
 | [1] |
in which AID is the apparent ileal digestibility of an AA (%), AAd is the concentration of that AA in the ileal digesta (g/kg of DM), AAf is the concentration of that AA in the diets (g/kg of DM), Crf is the chromium concentration in the diet (g/kg of DM), and Crd is the chromium concentration in the ileal digesta (g/kg of DM). The AID for CP was also calculated using this equation.
The IAAend of each AA was determined based on the flow obtained after feeding the N-free diet using Eq. [2]:
 | [2] |
in which IAAend is the basal ileal endogenous loss of an AA (g/kg of DMI). The endogenous flow of CP was determined using the same equation.
By correcting the AID that was calculated for each sample for the IAAend of each AA, standardized ileal digestibility values (SID) were calculated using Eq. [3]:
 | [3] |
in which SID is the standardized ileal digestibility of an AA (%).
The apparent total tract digestibilities (ATTD) of DM and energy in all diets were calculated using Eq. 1. By multiplying the analyzed concentration of GE in the diets by the corresponding ATTD for energy, the DE in each diet was calculated. The DE in each of the DDGS samples was calculated by subtracting one-third of the DE in the N-free diet from the DE in each of the DDGS-containing diets according to the difference procedure (Adeola, 2001). The digestibility of energy in corn was determined using the direct approach (Adeola, 2001).
Statistical Analysis
Data were analyzed statistically using the Proc GLM procedure of SAS (SAS Inst. Inc., Cary, NC). The pig was the experimental unit. The 10 sources of DDGS were compared using an ANOVA with DDGS source, pig, and period as the main effects. A LSD test was performed to separate the means. The values for corn were compared with the values for DDGS using a contrast statement. An alpha level of 0.05 was used to assess significance among means.
|
RESULTS |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONIMPLICATIONSLITERATURE CITED |
|---|
The AID for CP in DDGS varied between 59.3 and 65.0% with the AID in sources 4 and 5 being lower (P < 0.001) than in sources 2, 3, 6, and 9 (Table 4). The AID for CP in corn was 51.7%, which was lower (P < 0.001) than the AID in DDGS.
|
The AID for the remaining indispensable AA were less variable than the AID for Lys, but significant differences among the 10 sources of DDGS were observed for all AA. For most of the indispensable AA, the AID for DDGS from sources 2, 3, 6, and 9 were greater (P < 0.05) than the AID measured in sources 4, 5, and 7.
The AID for Arg, Thr, and Trp in corn (62.7, 55.1, and 48.9%, respectively) were lower (P < 0.01) than the AID in DDGS. In contrast, the AID for His in corn (73.6%) was greater (P < 0.01) than in DDGS. However, for the remaining indispensable AA, the AID in corn was within the range measured in the 10 sources of DDGS.
For the dispensable AA, the variations among samples were relatively low. However, for most of the indispensable AA, the AID in sources 2, 3, 6, 9, and 10 were greater (P < 0.05) than the AID in sources 1, 4, 5, 7, and 8. The AID for Glu, Gly, Pro, and Tyr in corn were lower (P < 0.04) than in DDGS, but for the other dispensable AA, the AID in corn was within the range measured for DDGS.
The SID for CP and all AA are presented in Table 5. The SID for CP in DDGS from sources 4 and 5 (66.7 and 67.7%, respectively) were lower (P < 0.05) than the SID for CP from sources 2, 3, 6, and 9 (72.0, 72.3, 72.1, and 72.8%, respectively). Likewise, for all indispensable AA except Arg, Leu, Lys, and Trp, the SID in sources 4 and 5 were lower (P < 0.05) than the SID in sources 2, 3, 6, and 9. For Arg, the SID in sources 4 and 5 were lower (P < 0.05) than in sources 2, 3, and 9. For Leu, the SID for sources 4 and 7 were lower (P < 0.05) than the SID in all other sources. For Lys, the SID ranged from 56.8 to 63.0% in all sources of DDGS except in sources 5 and 8. These values were not different, but they were greater (P < 0.05) than the SID in sources 5 and 8 (43.9 and 48.6%, respectively).
|
The SID for CP, Arg, and Gly in corn (71.2, 76.7, and 53.5%, respectively) were not different from the SID in DDGS. The SID for Trp and Pro in corn (72.8 and 48.3%, respectively, were lower (P < 0.05) than in DDGS. However, for all other AA, the SID for corn were greater (P < 0.01) than in DDGS.
The ATTD of DM and GE in the corn diet (87.6 and 85.1%, respectively) were greater (P < 0.001) than the values in all the diets containing DDGS (Table 6). The ATTD of DM and GE in DDGS from source 2 (72.6 and 70.5%, respectively) was greater (P < 0.05) than in the samples from all other sources except source 5. The ATTD of DM for source 5 (70.5%) also was greater (P < 0.05) than the ATTD for sources 4, 7, and 10. Likewise, the ATTD of GE in source 5 (69.0%) was greater (P < 0.05) than the ATTD for GE in sources 1, 4, 7, 8, and 10. However, there were no differences in the ATTD of DM or GE among DDGS from sources 1, 3, 4, 6, 7, 8, 9, and 10.
|
|
DISCUSSION |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONIMPLICATIONSLITERATURE CITED |
|---|
; Spiehs et al., 2002). Likewise, with the exception of Trp, the concentrations of all AA in the DDGS samples also agreed with previously reported values (NRC, 1998; Spiehs et al., 2002). Values for ADF concentrations in the DDGS ranged from 8.0 to 13.1% (as fed-basis), which is equivalent to a range of 9.2 to 14.4% on a DM-basis. Values of ADF ranging from 13.8 to 17.1% (DM-basis) were reported by Spiehs et al. (2002), and an average value of 17.4% (DM-basis) also has been reported (NRC, 1998). It is not known why the ADF concentrations were lower in the DDGS used in the current experiment, but it may be a result of more effective enzyme combinations being used in the fermentation process.
The Glu:CP ratio was lower in all the DDGS-based diets than in the corn-based diet, which may have been caused by the yeast that is used in the fermentation process. Yeast prefers to use Glu as an energy source (Sharp and Chambers, 1983).
Digestibility of Crude Protein and Amino Acids
The AID and SID for Met, Cys, and Trp in DDGS were generally greater than published values, but for the remaining indispensable AA, the AID and SID measured in this experiment were in agreement with published values (NRC, 1998). Except for Lys, the lowest AID and SID for the indispensable AA were obtained for Thr. This is also in agreement with published values (NRC, 1998).
Among the 10 samples of DDGS, significant differences in the SID for CP and all AA were obtained. For CP and all AA except Ile, Lys, Trp, and Pro, the numerically highest SID were obtained in DDGS from source 9 and the lowest SID were obtained for CP and all AA except His, Lys, Thr, and Asp in the DDGS from source 4. However, with the exception of the SID of Lys in sources 5 and 8, the variations in SID for CP and all indispensable AA except Met among the DDGS samples were between 5.8 and 8.4 percentage units. For Met, the SID ranged from 73.9 to 84.7%. Previously, AID values for all indispensable AA except Arg in 6 cultivars of field peas were reported to vary from 5.3 to 17.3 percentage units (Fan and Sauer, 1999). Using a rat model, van Wijk et al. (1998) reported variations in AID of 8.5 to 18.9 percentage units for the indispensable AA in 20 cultivars of barley. It seems that with the exception of the values for Lys in sources 5 and 8, the variation obtained in AID and SID for indispensable AA among samples of DDGS obtained in the current study are no greater than the variations reported among different cultivars of field peas and barley, respectively.
The low AID and SID for Lys in the DDGS from sources 5 and 8 may be a result of the Maillard reaction that takes place during heating if reducing sugars are present (Mauron, 1981). Reducing sugars would be present if an incomplete fermentation and starch removal has occurred. The current results indicate that an incomplete fermentation and overheating may have occurred in the 2 plants supplying the DDGS designated as sources 5 and 8.
The reason why the AID for most AA in corn were similar to DDGS whereas the SID for most AA in corn were greater than in DDGS is that feed ingredients with a low CP and AA concentration usually have low AID because IAAend contribute relatively more to the ileal output of AA compared with feed ingredients with a moderate or high concentration of CP and AA (Fan et al., 1994; Pedersen and Boisen, 2002). When SID are calculated, the influence of the IAAend is eliminated, which explains why the values for corn increased relative to the values for the DDGS samples. The fact that the SID for most AA in corn are greater than they are in DDGS indicate that not all the AA in DDGS are utilized as well as they are in corn. Because DDGS contains more fiber than corn and because fiber negatively influences the digestibility of AA (Mosenthin et al., 1994; Lenis et al., 1996), the reduced SID for some AA in DDGS may have been caused by the increased fiber concentration in DDGS. It is also possible that some of the AA may have been altered by the microbes during the fermentation process and used in the synthesis of microbial protein, which in turn could result in differences in AA digestibility values.
Dry Matter and Energy Digestibility
The results of the current experiment indicate that the DE concentration in DDGS ranges from 3,382 to 3,811 kcal of DE per kg of DM. The average value for the 10 samples (3,556 kcal of DE per kg of DM) is slightly greater than the value of 3,440 kcal of DE per kg of DM that has been published (NRC, 1998). Previously, Spiehs et al. (2002) calculated the DE in 11 or 12 samples of DDGS from each of 10 ethanol plants in the Midwest and reported average values for each plant ranging from 3,879 to 4,084 kcal of DE per kg of DM.
The ATTD for GE varied from 62.7 to 70.5% among the 10 samples of DDGS. The samples that had the highest ATTD for GE also had the highest ATTD for DM, and it seems that DM digestibility is a good predictor of energy digestibility. The variation in the ATTD for GE is similar to the variation reported among 5 cultivars of barley (Fairbairn et al., 1999). The highest value for DE was obtained for the DDGS from source 2. This sample also had the lowest concentration of ADF and the highest concentration of starch. The highest concentrations of ADF were found in sources 7 and 8 and these sources had concentrations of starch and DE that were among the lowest of all samples. Thus, it seems that the DE in DDGS to some degree is related to the concentration of starch and ADF in the sample, but not all differences in DE concentrations can be explained by the concentration of these 2 nutrients.
|
IMPLICATIONS |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONIMPLICATIONSLITERATURE CITED |
|---|
|
Footnotes |
|---|
2 Financial support from Dakota Gold Research Association, Sioux Falls, SD, and from the South Dakota Corn Utilization Council, Sioux Falls, is greatly appreciated.
3 Corresponding author: hans.stein{at}sdstate.edu
Received for publication April 14, 2005. Accepted for publication November 7, 2005.
|
LITERATURE CITED |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONIMPLICATIONSLITERATURE CITED |
|---|
This article has been cited by other articles:
|
|
 |
|
  B. J. Kerr, C. J. Ziemer, T. E. Weber, S. L. Trabue, B. L. Bearson, G. C. Shurson, and M. H. Whitney Comparative sulfur analysis using thermal combustion or inductively coupled plasma methodology and mineral composition of common livestock feedstuffs J Anim Sci, September 1, 2008; 86(9): 2377 - 2384. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. A. Pahm, C. Pedersen, D. Hoehler, and H. H. Stein Factors affecting the variability in ileal amino acid digestibility in corn distillers dried grains with solubles fed to growing pigs J Anim Sci, September 1, 2008; 86(9): 2180 - 2189. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Widmer, L. M. McGinnis, D. M. Wulf, and H. H. Stein Effects of feeding distillers dried grains with solubles, high-protein distillers dried grains, and corn germ to growing-finishing pigs on pig performance, carcass quality, and the palatability of pork J Anim Sci, August 1, 2008; 86(8): 1819 - 1831. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Linneen, J. M. DeRouchey, S. S. Dritz, R. D. Goodband, M. D. Tokach, and J. L. Nelssen Effects of dried distillers grains with solubles on growing and finishing pig performance in a commercial environment J Anim Sci, July 1, 2008; 86(7): 1579 - 1587. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Moore, K. J. Stalder, D. C. Beitz, C. H. Stahl, W. A. Fithian, and K. Bregendahl The correlation of chemical and physical corn kernel traits with growth performance and carcass characteristics in pigs J Anim Sci, March 1, 2008; 86(3): 592 - 601. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Widmer, L. M. McGinnis, and H. H. Stein Energy, phosphorus, and amino acid digestibility of high-protein distillers dried grains and corn germ fed to growing pigs J Anim Sci, November 1, 2007; 85(11): 2994 - 3003. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Roberts, H. Xin, B. J. Kerr, J. R. Russell, and K. Bregendahl Effects of Dietary Fiber and Reduced Crude Protein on Nitrogen Balance and Egg Production in Laying Hens Poult. Sci., August 1, 2007; 86(8): 1716 - 1725. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Pedersen, M. G. Boersma, and H. H. Stein Digestibility of energy and phosphorus in ten samples of distillers dried grains with solubles fed to growing pigs J Anim Sci, May 1, 2007; 85(5): 1168 - 1176. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
