| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ANIMAL NUTRITION |
* Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506; and
Poet Energy, Sioux Falls, SD 57104
 |
Abstract |
|---|
 Top Abstract INTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONLITERATURE CITED |
|---|
0.48) for yearling heifers fed CONT when compared with heifers fed DGS. Heifers fed TRAD consumed more (P = 0.01) feed than heifers fed FRAC. However, ADG and feed efficiency were not different (P 0.07) for heifers fed DGS. Moderate inclusion levels of DGS in finishing flaked corn diets yielded satisfactory performance. Growth performance was not different for heifers fed DGS originating from either ethanol processing method.
Key Words: distillers grain • feedlot • heifer • partial fractionation
|
INTRODUCTION |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONLITERATURE CITED |
|---|
). Ethanol production is on course to meet and possibly exceed the 2012 target of 7.5 billion gallons per year set forth by the Energy Policy Act of 2005 (H.R. 6; Renewable Fuels Association, 2006). Inherent with ethanol production are co-products such as distillers grains with solubles (DGS). Almost 70% of ethanol is produced by traditional dry-grind ethanol plants (Renewable Fuels Association, 2006). In these processes, the entire kernel (i.e., fermentable and nonfermentable components) is subjected to fermentation (Rausch and Belyea, 2006). Rausch and Belyea (2006) describe the basic steps of a dry-grind plant as grinding, cooking, liquefaction, saccharification, fermentation, ethanol distillation, and removal of water from stillage to form dried DGS. Partial fractionation dry-grind processes are different, because the kernel undergoes physical separation or fractionation before the cooking process. The nonfermentable portions of the grain, such as the germ, are not subjected to the fermentation process and can be further processed to yield corn oil. Traditional DGS contain the residual components (i.e., bran, protein, germ, and minerals) of the grain after the majority of the starch has been fermented (NRC, 1996). The future of the grain-based ethanol industry is heading toward a fractionation process. Fractionation of the grain increases fermentation efficiency and increases market opportunities for by-products (Rajagopalan et al., 2005; Rausch and Belyea, 2006). Distillers grains with solubles derived from the partial fractionation dry-grind ethanol process contain less fat (i.e., germ) and phosphorus but have greater concentrations of protein (Rausch and Belyea, 2006). High concentrations of phosphorus in DGS can lead to practical limits due to concerns over nutrient management. The distillers grains available today may not be the same as the distillers grains available in the future from the partial fractionation dry-grind ethanol process. Our objective was to compare growth performance and carcass characteristics in yearling heifers fed finishing diets based on steam-flaked corn with or without DGS produced from either a traditional dry-grind or a partial fractionation dry-grind process. |
MATERIALS AND METHODS |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONLITERATURE CITED |
|---|
Six hundred ten crossbred-yearling heifers (347 ± 5 kg of initial BW) were used in a randomized complete-block designed finishing study. Whole corn was steam-flaked to a bulk density of 360 g/L with a mean geometric particle size of 5,724 ± 601 µm (n = 159). The control diet (CONT) contained no DGS (Table 1). The second diet contained 13% (DM basis) of dried corn DGS (TRAD) derived from a traditional dry-grind ethanol process. The third diet contained 13% (DM basis) of dried corn DGS from a partial fractionation dry-grind ethanol process (FRAC). All 3 finishing diets were formulated (Table 2) to be 14% CP first using urea and then using soybean meal as required. However, after analyzing the weekly ingredient samples, the actual CP concentrations were 14.8, 13.8, and 13.9% for CONT, TRAD, and FRAC, respectively.
|
|
). Heifers were housed in dirt-surfaced pens (approximately 19.5 m2/heifer) with automatic water fountains and 10 m of bunk space (0.41 m/heifer). On d 118, cattle were shipped 182 km to a commercial abattoir in Emporia, Kansas, where carcass data were collected. Carcass weight and liver abscess scores were obtained at the time of harvest. Longissimus muscle area, s.c. fat thickness over 12th rib, and percentage of kidney, pelvic, and heart fat data were obtained after a 24-h chill. In addition, marbling score, quality grades, and yield grades were acquired from USDA meat inspectors. Final BW was calculated by dividing carcass weight by a common dress yield of 63.5%.
Statistical Analysis
Growth performance and carcass characteristics were analyzed using the MIXED procedure (SAS Inst. Inc., Cary, NC). Pen was the experimental unit, and block was used as the random effect. Treatment averages were calculated using the LSMEANS option of SAS and separated using a protected F-test (P 
0.05). Orthogonal contrasts were also used to compare CONT to the average of TRAD and FRAC. The orthogonal contrast was also protected using the F-test (P 0.05).
|
RESULTS AND DISCUSSION |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONLITERATURE CITED |
|---|
Dry matter intake was not different (Table 3; P = 0.80) for yearling heifers fed CONT compared with heifers fed either TRAD or FRAC. Previous research from Larson et al. (1993) and Daubert et al. (2005) suggests a linear decrease in DMI when sorghum-wet or corn-wet DGS was increased from 0 to 40% of the diet DM, respectively. Farlin (1981) also observed a decrease in DMI when 64% of the finishing diet was corn-wet DGS, but showed no difference in DMI when 21% corn-wet DGS was fed. Similarly, Depenbusch et al. (2008) also observed no difference in DMI when 25% corn-wet DGS was fed to yearling heifers. Ham et al. (1994) fed greater levels of dried and wet corn DGS and observed no difference in DMI. In addition, Lodge et al. (1997) and Al-Suwaiegh et al. (2002) showed similar results when they fed either dried or sorghum-wet DGS. The results from our study support the preponderance of available data, which suggest that low to moderate inclusion of DGS has no effect on DMI.
|
observed a quadratic response to urea when it was fed at 0, 0.35, 0.70, 1.05, and 1.40% on a DM basis. Dry matter intake was greatest between 0.70 and 1.05% urea. It is plausible that degradable intake protein was limited in the FRAC diet and thereby reduced digestion, passage rate, and hence DMI. However, work by Vasconcelos et al. (2007) observed just the opposite. They fed graded levels of urea in steam-flaked corn diets containing 10% wet DGS and showed a linear reduction in DMI with no differences in ADG and gain efficiency.
Daily weight gain and gain efficiencies were not different (P 0.07) among treatments. Lodge et al. (1997) also reported no improvement in ADG and feed efficiency when 40% sorghum-wet or sorghum-dry DGS were fed. However, Larson et al. (1993), Ham et al. (1994), and Al-Suwaiegh et al. (2002) observed improvements in ADG and feed efficiency when up to 30% of dry-rolled corn was replaced with DGS. Farlin (1981) also observed improvements in ADG and gain efficiency at even greater levels (i.e., 64%) of DGS. Firkins et al. (1985) observed similar results to Farlin (1981) when up to 50% of high-moisture corn and SBM was replaced with corn-wet DGS. However, Daubert et al. (2005) fed 0, 8, 16, 24, 32, and 40% sorghum-wet DGS and observed a quadratic response for ADG and gain efficiency with the optimal level between 8 and 16% in a finishing diet based on steam-flaked corn. Vander Pol et al. (2006b) fed 0, 10, 20, 30, 40, and 50% wet DGS and observed a quadratic response for ADG and gain efficiency. However, their research suggests an optimal level of 30 to 40% when fed in dry-rolled corn finishing diets. In another study by Vander Pol et al. (2006a), it was observed that steers fed finishing diets based on dry-rolled corn with 30% corn-wet DGS gained more weight than those fed finishing diets based on steam-flaked corn with 30% corn-wet DGS. Research from Depenbusch et al. (2007) with finishing diets based on steam-flaked corn observed no differences in DMI, ADG, and gain efficiency for yearling steers fed either 0 or 15% corn-dry or corn-wet DGS. However, in another study, Depenbusch et al. (2008) observed a reduction in ADG and feed efficiency when a portion of steam-flaked corn was replaced with 25% corn-wet DGS. In the studies by Daubert et al. (2005) and Depenbusch et al. (2007, 2008) as well as the current study, steam-flaked corn was the predominant ingredient, whereas dry-rolled corn or a combination of dry-rolled and high-moisture corn was used by Larson et al. (1993), Ham et al. (1994), Lodge et al. (1997), Al-Suwaiegh et al. (2002), and Vander Pol et al. (2006a, b). The National Research Council (1984, 1996) reports that steam-flaked corn has a 4 and 5% greater NEm and NEg, respectively, when compared with dry-rolled corn. Research from Barajas and Zinn (1998) and Zinn et al. (1998) suggest that the feeding value of steam-flaked corn is 10 to 16% greater than that of dry-rolled corn. Differences in basal ingredients such as steam-flaked corn vs. dry-rolled corn may explain why we did not observe the same improvement in animal performance as Larson et al. (1993), Ham et al. (1994), Al-Suwaiegh et al. (2002), and Vander Pol et al. (2006a, b).
Ruminal starch fermentation is greater for finishing diets based on steam-flaked corn when compared with dry-rolled corn (Zinn et al., 1995; Huntington 1997; Barajas and Zinn 1998). Zinn et al. (1995), Barajas and Zinn (1998), and Corona et al. (2006) observed a lower acetate:propionate ratio and lower ruminal pH for steers fed finishing diets based on steam-flaked corn rather than dry-rolled corn. Rumen pH for feedlot cattle fed finishing diets based on steam-flaked corn are commonly observed below pH 6.0 (Zinn et al., 1995; Corona et al., 2006; Sindt et al., 2006). In vitro studies summarized by Russell and Wilson (1996) suggest a rapid decline in activity of fibrolytic organisms when pH fell below 6.2. In addition, the optimal pH range for cellulases of ruminal bacteria is rarely below pH 6.0 (Huang et al., 1988; McGavin and Forsberg, 1988; McGavin et al., 1989). The National Research Council (1996) estimates the NDF value of DGS to be 46%; however, NDF values for TRAD and FRAC in our study were 26 and 23%, respectively. Therefore, it is plausible that DGS may have a decreased feeding value in steam-flaked corn diets when compared with dry-rolled corn diets. This is supported by research from Vander Pol et al. (2006a), Corrigan et al. (2007), and May et al. (2007) that showed growth performance was greater for cattle fed dry-rolled corn and DGS compared with cattle fed steam-flaked corn and DGS. This difference may be attributed to the lower ruminal pH in steam-flaked corn diets and its adverse effect on ruminal digestion of the fiber portion of the DGS.
Carcass Data
Carcass data are summarized in Table 4. Carcass weight, dress yield, LM area, KPH fat, and 12th-rib fat were not different (P 0.14) among treatments. Likewise, USDA yield and quality grade, marbling score, and percentage of liver abscesses were not different (P 0.11) among treatments. Previous research by Larson et al. (1993) and Lodge et al. (1997) supports the findings that inclusion of DGS does not affect carcass characteristics. In addition, Roeber et al. (2005) showed that feeding DGS up to 25% of the diet had little effect on meat quality of Holstein steers. Recent research by Corrigan et al. (2007) observed a linear effect of wet DGS on carcass weight and a quadratic effect on 12th-rib fat in steers fed dry-rolled corn diets. In addition, they observed a quadratic effect of wet DGS on carcass weight and 12th-rib fat in steers fed steam-flaked corn diets. However Depenbusch et al. (2008) observed a 3.5% reduction in carcass weight and a 3.2% reduction in LM area when 25% wet DGS was fed in a steam-flaked corn diet. Al-Suwaiegh et al. (2002) showed that 30% of corn-wet or sorghum-wet DGS significantly increased 12th-rib fat thickness and USDA yield grade. Research by Daubert et al. (2005) showed that increasing sorghum-wet DGS from 0 to 40% linearly increased USDA yield grade while linearly decreasing marbling score. Depenbusch et al. (2008) observed no difference in 12th-rib fat thickness and USDA yield grade when 25% corn-wet DGS was fed to yearling heifers. However, the authors did find a reduction in marbling score in USDA Choice or better carcasses.
|
|
Footnotes |
|---|
2 Corresponding author: jdrouill{at}ksu.edu
Received for publication August 6, 2007. Accepted for publication April 16, 2008.
|
LITERATURE CITED |
|---|
|
TopAbstractINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONLITERATURE CITED |
|---|
This article has been cited by other articles:
|
|
 |
|
  M. L. May, M. J. Quinn, N. DiLorenzo, D. R. Smith, K. E. Hales, D. D. Simms, and M. L. Galyean Effects of Adding MIN-AD to Steam-Flaked Corn-Based Diets With or Without Wet Corn Distillers Grain Plus Solubles on Performance by Beef Cattle During Receiving and Finishing Phases Professional Animal Scientist, October 1, 2009; 25(5): 559 - 568. [Abstract] [PDF]
|
|
|
|
 |
|
 B. E. Depenbusch, E. R. Loe, J. J. Sindt, N. A. Cole, J. J. Higgins, and J. S. Drouillard Optimizing use of distillers grains in finishing diets containing steam-flaked corn J Anim Sci, August 1, 2009; 87(8): 2644 - 2652. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. E. Depenbusch, C. M. Coleman, J. J. Higgins, and J. S. Drouillard Effects of increasing levels of dried corn distillers grains with solubles on growth performance, carcass characteristics, and meat quality of yearling heifers J Anim Sci, August 1, 2009; 87(8): 2653 - 2663. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
