RESULTS AND DISCUSSION
The nutrient concentrations of individual feed ingredients sampled throughout the study are presented in
Table 2. These values were not statistically analyzed because of inherent differences among the feedstuffs used in this study; however, evaluating nutrient concentrations over time allows for improved understanding of ingredient variability. Consequently, this could provide information for nutritionists and feedlot managers making decisions regarding diet formulations and commodity management. Of particular interest is the nutrient composition of SB and WDGS, as these feedstuffs are believed to have more variable nutrient concentrations because of inconsistencies in the wet and dry milling processes used to manufacture these ingredients. The average DM, CP, and crude fat concentrations were 60.33, 22.45, and 2.93% and 31.02, 35.35, and 10.37% for SB and WDGS, respectively. These values are similar to those reported by the
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle. 8th rev. ed. Natl. Acad. Press.
, except the CP concentration was slightly greater for the WDGS used in this study (35.35 vs. 30.63%;
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle. 8th rev. ed. Natl. Acad. Press.
).
Table 2Individual feed ingredient1SB = Sweet Bran (Cargill, Corn Milling); WDGS = wet distillers grains with solubles; SFC = steam-flaked corn; CS = corn stalks; and CSM = cottonseed meal.
nutrient composition of finishing diets containing different concentrations of corn-milling products Dry matter concentrations were most variable for WDGS, followed by SB, and least for cottonseed meal. Interestingly, ground corn stalks exhibited the greatest CV of the ingredients used in this study for CP and crude fat. This could be a function of sampling error or high variability in the composition of the ground corn stalks. Corn stalks were processed through a grinder before feeding to improve distribution and mixing ability but contained a mixture of stalks, cobs, and fines. It may also be more challenging to obtain a representative sample of corn stalks because of the degree of variation in particle size and density present within the ground feed. The average total starch and starch availability of SFC was 78.93% (minimum = 74.40%; maximum = 83.40%; CV = 3.02%; data not shown) and 58.56% (minimum = 44.00%; maximum = 75.00%; CV = 11.90%; data not shown), respectively. The starch availability of SFC used in this study is typical for feedlot cattle (
Schwandt et al., 2016.- Schwandt E.
- Hubbert M.
- Thomson D.
- Vahl C.
- Bartle S.
- Reinhardt C.
A survey of starch availability of steam-flaked corn in commercial feedlots evaluating roll size and flake density..
).
Initial BW and BW at the end of the transition period did not differ (
P ≥ 0.85) among dietary treatments (
Table 3). Similarly, DMI, ADG, and G:F did not differ during the transition period (d 0 to 20;
P ≥ 0.44). The lack of difference in performance during the transition period was expected because all cattle were consuming at least a portion of their daily DMI as the common growing diet during this time. Although the amount of each dietary treatment cattle were consuming increased as the transition period progressed, this may not have allowed enough time to result in detectable differences in performance. Final BW was greater (
P < 0.01) for cattle consuming WDGS20, SB20, and COMBO than CON but was similar among cattle consuming the diets containing corn-milling products. The difference in final BW is a direct reflection of greater (
P < 0.01) DMI and ADG for WDGS20, SB20, and COMBO compared with CON from transition to final (d 20 to final) and overall (d 0 to final). Over the entire feeding period, DMI was 6.81, 7.25, and 5.93% greater for WDGS20, SB20, and COMBO than CON, respectively. Similarly, ADG was 5.77, 5.77, and 3.85% greater for WDGS20, SB20, and COMBO than CON. Because dietary concentrations of NE
g were relatively similar among treatments (1.46, 1.48, 1.47, and 1.47 Mcal/kg for CON, WDGS, SB20, and COMBO, respectively), the greater ADG and final BW of cattle consuming corn-milling products was primarily influenced by increased DMI. However, it is important to note that both the NE
m and NE
g concentrations depicted in
Table 1 were calculated based on tabular values (
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle. 8th rev. ed. Natl. Acad. Press.
), and the energy estimates could vary from actual energy content calculated from the GE of a specific feed sample. Therefore, it is important to use caution when interpreting performance of cattle consuming diets containing corn-milling products because of potential variation in the actual energy content of feeds such as WDGS and SB from variations in the manufacturing process. Also, the tabular values reported for NE
m and NE
g of WDGS have increased over time as revealed in the
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2000. Nutrient Requirements of Beef Cattle: Update 2000. Natl. Acad. Press.
versus
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle. 8th rev. ed. Natl. Acad. Press.
publications, which were reported as 2.24 and 1.55 Mcal/kg and 2.47 and 1.74 Mcal/kg, respectively. These differences also present challenges because it can be difficult to delineate which tabular value is most appropriate for use in calculations and interpretations of animal performance. Because both DMI and ADG increased proportionally from including corn-milling products in the diet, G:F did not differ (
P ≥ 0.48) from transition to final or overall.
Table 3Effects of diets containing no fibrous corn-milling products or wet distillers grains with solubles, Sweet Bran, or both on finishing cattle performance
a,bMeans within a row with different superscript letters differ, P < 0.05.
Greater final BW, DMI, and ADG concomitant with similar G:F of cattle consuming SB is consistent with previous studies evaluating feedlot performance of cattle fed SFC-based diets. For example, increasing SB from 0.0 to 40.0% of DM quadratically increased DMI and ADG but did not affect G:F (
Block et al., 2005.- Block H.C.
- Macken C.N.
- Klopfenstein T.J.
- Erickson G.E.
- Stock R.A.
Optimal wet corn gluten and protein levels in steam-flaked corn-based finishing diets for steer calves..
). Consequently,
Block et al., 2005.- Block H.C.
- Macken C.N.
- Klopfenstein T.J.
- Erickson G.E.
- Stock R.A.
Optimal wet corn gluten and protein levels in steam-flaked corn-based finishing diets for steer calves..
concluded that finishing cattle performance is maximized when 17.0 to 23.0% of dietary DM is supplied by SB. Greater DMI, ADG, and similar G:F were also observed by
Scott et al., 2003.- Scott T.L.
- Milton C.T.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Corn processing method in finishing diets containing wet corn gluten feed..
and
Loza et al., 2010.- Loza P.L.
- Buckner C.D.
- Vander Pol K.J.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effect of feeding combinations of wet distillers grains and wet corn gluten feed to feedlot cattle..
. In a study completed by
Parsons et al., 2007.- Parsons C.H.
- Vasconcelos J.T.
- Swingle R.S.
- Defoor P.J.
- Nunnery G.A.
- Salyer G.B.
- Galyean M.L.
Effects of wet corn gluten feed and roughage levels on performance, carcass characteristics, and feeding behavior of feedlot cattle..
, DMI was also greater when diets contained either 20.0 or 40.0% SB compared with no SB. In contrast to the current study, ADG only tended to be greater with SB, which resulted in less G:F because the improvements in live gain in the study by
Parsons et al., 2007.- Parsons C.H.
- Vasconcelos J.T.
- Swingle R.S.
- Defoor P.J.
- Nunnery G.A.
- Salyer G.B.
- Galyean M.L.
Effects of wet corn gluten feed and roughage levels on performance, carcass characteristics, and feeding behavior of feedlot cattle..
were not proportional to the increase in DMI.
Macken et al., 2004.- Macken C.N.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effects of concentration and composition of wet corn gluten feed in steam-flaked corn-based finishing diets..
reported DMI tended to be greater when diets included 20.0 to 35.0% SB, but only numerical increases in final BW and ADG were observed. However, the study completed by
Macken et al., 2004.- Macken C.N.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effects of concentration and composition of wet corn gluten feed in steam-flaked corn-based finishing diets..
only consisted of 4 pen replicates per treatment and therefore may have not had adequate statistical power to detect differences in cattle DMI and performance.
Results from research evaluating WDGS in finishing cattle diets are less consistent than studies completed using SB. Generally, replacing a portion of diets based on HMC, DRC, or both with WDGS results in similar DMI, increased ADG, and greater G:F than diets containing no corn-milling products (
Klopfenstein et al., 2008.- Klopfenstein T.J.
- Erickson G.E.
- Bremer V.R.
Board-Invited Review: Use of distillers by-products in the beef cattle feeding industry..
). However, in SFC-based feedlot cattle diets, the response to added WDGS is less clear. It has been suggested that WDGS has a lower energy value than SFC, and therefore replacing SFC with WDGS may reduce dietary energy concentration and negatively affect animal performance. Consequently, the interaction between corn processing method and WDGS has been extensively studied, but results are inconsistent (
Corrigan et al., 2009.- Corrigan M.E.
- Erickson G.E.
- Klopfenstein T.J.
- Luebbe M.K.
- Vander Pol K.J.
- Meyer N.F.
- Buckner C.D.
- Vanness S.J.
- Hanford K.J.
Effect of corn processing method and corn wet distillers grains plus solubles inclusion level in finishing steers..
;
Leibovich et al., 2009.- Leibovich J.
- Vasconcelos J.
- Galyean M.
Effects of corn processing method in diets containing sorghum wet distillers grain plus solubles on performance and carcass characteristics of finishing beef cattle and on in vitro fermentation of diets..
;
Buttrey et al., 2012.- Buttrey E.K.
- Cole N.A.
- Jenkins K.H.
- Meyer B.E.
- McCollum III, F.T.
- Preece S.L.M.
- Auvermann B.W.
- Heflin K.R.
- MacDonald J.C.
Effects of twenty percent corn wet distillers grains plus solubles in steam-flaked and dry-rolled corn-based finishing diets on heifer performance, carcass characteristics, and manure characteristics..
).
Similar to the current study,
Ponce et al., 2019.- Ponce C.H.
- Cole N.A.
- Sawyer J.
- da Silva J.C.B.
- Smith D.R.
- Maxwell C.
- Brown M.S.
Effects of wet corn distiller’s grains with solubles and nonprotein nitrogen on feeding efficiency, growth performance, carcass characteristics, and nutrient losses of yearling steers.
reported greater DMI and ADG and similar G:F when 15.0% of WDGS was added to SFC-based diets.
Corrigan et al., 2009.- Corrigan M.E.
- Erickson G.E.
- Klopfenstein T.J.
- Luebbe M.K.
- Vander Pol K.J.
- Meyer N.F.
- Buckner C.D.
- Vanness S.J.
- Hanford K.J.
Effect of corn processing method and corn wet distillers grains plus solubles inclusion level in finishing steers..
also observed DMI and ADG increased when WDGS was included in the diet at 10.0 or 15.0% of DM but was less for cattle fed 27.5% of DM or greater as WDGS. In a study completed by
Depenbusch et al., 2008.- Depenbusch B.E.
- Drouillard J.S.
- Loe E.R.
- Higgins J.J.
- Corrigan M.E.
- Quinn M.J.
Efficacy of monensin and tylosin in finishing diets based on steam-flaked corn with and without corn wet distillers grains with solubles..
, cattle fed diets containing 25.5% WDGS had less ADG, similar DMI, and lower G:F compared with cattle consuming no corn-milling products. When combined with the results of the present study, these data suggest the optimum concentration of WDGS in SFC-based diets is likely between 15.0 and 25.0% of DM. In contrast,
May et al., 2010.- May M.L.
- DeClerck J.C.
- Quinn M.J.
- DiLorenzo N.
- Leibovich J.
- Smith D.R.
- Hales K.E.
- Galyean M.L.
Corn or sorghum wet distillers grains with solubles in combination with steam-flaked corn: feedlot cattle performance, carcass characteristics, and apparent total tract digestibility..
reported adding 15.0 or 30.0% of WDGS to SFC-based diets tended to decrease DMI, decreased ADG, and did not affect G:F. Alternatively,
Depenbusch et al., 2009.- Depenbusch B.E.
- Loe E.R.
- Sindt J.J.
- Cole N.A.
- Higgins J.J.
- Drouillard J.S.
Optimizing use of distillers grains in finishing diets containing steam-flaked corn..
observed no difference in DMI, ADG, or G:F of cattle consuming diets with 15.0% or no WDGS, and other research has reported increased DMI but reduced ADG and G:F with WDGS (
McDaniel et al., 2021.- McDaniel M.R.
- Tracey L.N.
- Cole N.A.
- Ivey S.L.
- Löest C.A.
Evaluation of whole corn substitution in diets based on steam-flaked corn containing different concentrations of wet distillers grains with solubles for beef cattle..
). The variation in research outcome associated with WDGS could be a function of differences in diet formulations between studies such as inclusion rate and starch availability of SFC, overall energy concentration, source and quality of roughage, dietary concentration of RDP, or both total and added fat concentration. For example, in the study by
May et al., 2010.- May M.L.
- DeClerck J.C.
- Quinn M.J.
- DiLorenzo N.
- Leibovich J.
- Smith D.R.
- Hales K.E.
- Galyean M.L.
Corn or sorghum wet distillers grains with solubles in combination with steam-flaked corn: feedlot cattle performance, carcass characteristics, and apparent total tract digestibility..
, 15.0% WDGS replaced a proportion of cottonseed meal, urea, yellow grease, molasses, and SFC and therefore only reduced the dietary concentration of SFC by 3.7%. In the current study as well as those by
Corrigan et al., 2009.- Corrigan M.E.
- Erickson G.E.
- Klopfenstein T.J.
- Luebbe M.K.
- Vander Pol K.J.
- Meyer N.F.
- Buckner C.D.
- Vanness S.J.
- Hanford K.J.
Effect of corn processing method and corn wet distillers grains plus solubles inclusion level in finishing steers..
and
Ponce et al., 2019.- Ponce C.H.
- Cole N.A.
- Sawyer J.
- da Silva J.C.B.
- Smith D.R.
- Maxwell C.
- Brown M.S.
Effects of wet corn distiller’s grains with solubles and nonprotein nitrogen on feeding efficiency, growth performance, carcass characteristics, and nutrient losses of yearling steers.
, SFC concentrations were reduced by 12.6, 10.0, and 10.0%, respectively. Less SFC likely contributed to lower dietary starch and perhaps influenced DMI. Furthermore, ethanol production has changed in the past 20 yr as greater amounts of fat are extracted from the final WDGS product, thus influencing nutrient composition and possibly performance of cattle consuming diets with WDGS.
In the current study, replacing SFC with WDGS, SB, or both resulted in greater DMI and ADG compared with a diet containing SFC and no corn-milling products, but G:F was not affected. The mechanism of action for greater DMI when corn-milling products are added to the diet is difficult to delineate but could be influenced by several factors. In comparison to fibrous ingredients, fermentation of grains increases the molar proportion of propionate in the rumen (
Penner et al., 2011.- Penner G.B.
- Steele M.A.
- Aschenbach J.R.
- McBride B.W.
Ruminant nutrition symposium: Molecular adaptation of ruminal epithelia to highly fermentable diets..
). In a study by
Montgomery et al., 2004.- Montgomery S.P.
- Drouillard J.S.
- Titgemeyer E.C.
- Sindt J.J.
- Farran T.B.
- Pike J.N.
- Coetzer C.M.
- Trater A.M.
- Higgins J.J.
Effects of wet corn gluten feed and intake level on diet digestibility and ruminal passage rate in steers..
, less ruminal propionate was observed as the WCGF concentration of the diet was increased from 0.0 to 40.0% of dietary DM in place of SFC. Similar results have also been observed with WDGS (
Luebbe et al., 2012.- Luebbe M.K.
- Patterson J.M.
- Jenkins K.H.
- Buttrey E.K.
- Davis T.C.
- Clark B.E.
- McCollum III, F.T.
- Cole N.A.
- MacDonald J.C.
Wet distillers grains plus solubles concentration in steam-flaked-corn-based diets: Effects on feedlot cattle performance, carcass characteristics, nutrient digestibility, and ruminal fermentation characteristics1..
). Greater hepatic oxidation of propionate may contribute to satiety (
Allen et al., 2009.- Allen M.S.
- Bradford B.J.
- Oba M.
Board invited review: The hepatic oxidation theory of control of feed intake and its application to ruminants..
). Although not measured in the present study, greater concentrations of propionate as a result of increased fermentation of starch by cattle consuming the CON diet could have initiated satiety and contributed to lower DMI. Differences in DMI among treatments could also be because of lower palatability of CON, possibly contributed by the greater DM concentration of this diet (82.90, 63.20, 74.90, and 66.30% for CON, WDGS20, SB20, and COMBO, respectively). However, adding water to the diet in an effort to equalize DM differences has decreased DMI in previous research (
Lahr et al., 1983.- Lahr D.A.
- Otterby D.E.
- Johnson D.G.
- Linn J.G.
- Lundquist R.G.
Effects of moisture content of complete diets on feed intake and milk production by cows..
;
Ham et al., 1994.- Ham G.A.
- Stock R.A.
- Klopfenstein T.J.
- Larson E.M.
- Shain D.H.
- Huffman R.P.
Wet corn distillers byproducts compared with dried corn distillers grains with solubles as a source of protein and energy for ruminants..
), suggesting that the lower DMI of CON in the present study was not because of differences in dietary DM. Alternatively, more rapid fermentation of starch in the rumen of cattle consuming CON could have caused feed aversion via initiation of a negative postingestive feedback response associated with low ruminal pH from the increased production of ruminal VFA (
Provenza, 1995.Postingestive feedback as an elementary determinant of food preference and intake in ruminants..
). It has been proposed that replacing processed grains with fibrous, corn-milling products such as WDGS and SB reduces DMI variation, modulates ruminal pH, and alters rumen microbial populations (
Krehbiel et al., 1995.- Krehbiel C.R.
- Stock R.A.
- Herold D.W.
- Shain D.H.
- Ham G.A.
- Carulla J.E.
Feeding wet corn gluten feed to reduce subacute acidosis in cattle..
;
Fron et al., 1996.- Fron M.
- Madeira H.
- Richards C.
- Morrison M.
The impact of feeding condensed distillers byproducts on rumen microbiology and metabolism..
). In a companion study,
Spowart et al., 2020.- Spowart P.R.
- Richeson J.T.
- Crawford D.M.
- Samuelson K.L.
Inclusion of Sweet Bran™ and wet distillers grains alone or in combination improves performance, carcass merit, and rumen buffering characteristics of feedlot cattle fed steam-flaked corn diets.
reported ruminal pH was greater for cattle consuming WDGS20, SB20, and COMBO than it was for cattle consuming CON, which supports the hypothesis that the increased DMI in the present study was caused by a reduction in ruminal acidosis.
Similar performance between WDGS20 and SB20 in the present study indicates that WDGS and SB can be used interchangeably in feedlot diets without sacrificing performance. This is interesting because WDGS and SB have different nutrient concentrations and energy densities (
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle. 8th rev. ed. Natl. Acad. Press.
). To our knowledge, there is a limited amount research that directly compares WDGS and SB or WCGF, particularly in cattle consuming SFC-based diets. In a receiving study, cattle fed DRC-based diets containing no corn-milling products, 30.0% WDGS, and 30.0% WCGF for 58 d followed by a 14-d adaptation period had similar DMI, but ADG and G:F were greater for cattle receiving 30.0% WDGS compared with 30.0% WCGF or the control diet (
Schlegel et al., 2013.- Schlegel E.R.
- Oleen B.E.
- Hollenbeck W.R.
- Montgomery S.P.
- Vahl C.I.
- Blasi D.A.
Wet distillers grain and solubles vs. wet corn gluten feed for newly received and growing cattle..
). Similarly,
Loza et al., 2010.- Loza P.L.
- Buckner C.D.
- Vander Pol K.J.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effect of feeding combinations of wet distillers grains and wet corn gluten feed to feedlot cattle..
reported cattle consuming HMC and DRC diets with 30.0% WDGS had less DMI, greater ADG, and greater G:F compared with cattle consuming diets with 30.0% SB. Again, dissimilarities between these results and those observed in the current research could be because of differences in dietary formulations or nutrient profile of the corn-milling products.
Because DMI and ADG were not reduced compared with WDGS20 or SB20 by replacing an additional 10.0% of SFC with WDGS in the COMBO treatment, replacing up to 30.0% of dietary DM with WDGS, SB, or both may improve DMI and live performance and reduce feed cost of gain of finishing cattle. Research evaluating SB in combination with WDGS in finishing cattle diets is also limited; however, feeding combinations of these ingredients in cattle diets is a common management practice in the commercial feedlot industry. This concept was explored by
Loza et al., 2010.- Loza P.L.
- Buckner C.D.
- Vander Pol K.J.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effect of feeding combinations of wet distillers grains and wet corn gluten feed to feedlot cattle..
to evaluate possible associative effects between SB and WDGS. The results reported by
Loza et al., 2010.- Loza P.L.
- Buckner C.D.
- Vander Pol K.J.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effect of feeding combinations of wet distillers grains and wet corn gluten feed to feedlot cattle..
are similar to the current study, where cattle consuming a 30.0% blend (1:1 ratio) of corn-milling products exhibited greater growth performance than those consuming a diet without corn-milling products but similar growth performance compared with those consuming either SB or WDGS alone. Alternatively,
Chiputwa, 2010Bremer, V. R., J. R. Benton, M. K. Luebbe, K. J. Hanford, G. E. Erickson, T. J. Klopfenstein, and R. Stock. 2009. Wet distillers grains plus solubles or solubles in feedlot diets containing wet corn gluten feed. Pages 64–65 in 2009 Nebraska Beef Cattle Reports. Rep. No. 506. Univ. Nebraska, Lincoln.
investigated the optimal inclusion rate of WDGS (ranging from 0.0 to 40.0%) when added to a 35.0% SB diet. However, with the increased fixed value of SB, all performance variables reported were either similar to the control diet (35.0% SB only) or decreased with added WDGS. In the studies completed by
Loza et al., 2010.- Loza P.L.
- Buckner C.D.
- Vander Pol K.J.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effect of feeding combinations of wet distillers grains and wet corn gluten feed to feedlot cattle..
and
Chiputwa, 2010Bremer, V. R., J. R. Benton, M. K. Luebbe, K. J. Hanford, G. E. Erickson, T. J. Klopfenstein, and R. Stock. 2009. Wet distillers grains plus solubles or solubles in feedlot diets containing wet corn gluten feed. Pages 64–65 in 2009 Nebraska Beef Cattle Reports. Rep. No. 506. Univ. Nebraska, Lincoln.
, SB replaced a combination of DRC and HMC or HMC only. In contrast,
Vasconcelos and Galyean, 2007.- Vasconcelos J.T.
- Galyean M.L.
Effects of proportions of wet corn gluten feed and distillers dried grains with solubles in steam-flaked, corn-based diets on performance and carcass characteristics of feedlot cattle..
fed a SFC-based diet with no corn-milling products, 7.0% DDGS, 20.0% SB, 13.0% SB and 7.0% DDGS, and 20.0% SB and 7.0% DDGS. Dry matter intake and ADG in the study by
Vasconcelos and Galyean, 2007.- Vasconcelos J.T.
- Galyean M.L.
Effects of proportions of wet corn gluten feed and distillers dried grains with solubles in steam-flaked, corn-based diets on performance and carcass characteristics of feedlot cattle..
were less for cattle consuming the diet containing no corn-milling products and did not differ among the diets containing various combinations of SB and DDGS, which agrees with the present research.
Similar to final BW, cattle consuming WDGS20, SB20, and COMBO had heavier carcasses (
Table 4;
P = 0.04) than CON, but DP did not differ (
P = 0.21), which is in agreement with previous research (
Block et al., 2005.- Block H.C.
- Macken C.N.
- Klopfenstein T.J.
- Erickson G.E.
- Stock R.A.
Optimal wet corn gluten and protein levels in steam-flaked corn-based finishing diets for steer calves..
;
Loza et al., 2010.- Loza P.L.
- Buckner C.D.
- Vander Pol K.J.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effect of feeding combinations of wet distillers grains and wet corn gluten feed to feedlot cattle..
). Marbling score, 12th-rib fat thickness, LM area, and the percentage of KPH did not differ (
P ≥ 0.33) between cattle receiving WDGS20, SB20, COMBO, or CON. This also agrees with
Buttrey et al., 2012.- Buttrey E.K.
- Cole N.A.
- Jenkins K.H.
- Meyer B.E.
- McCollum III, F.T.
- Preece S.L.M.
- Auvermann B.W.
- Heflin K.R.
- MacDonald J.C.
Effects of twenty percent corn wet distillers grains plus solubles in steam-flaked and dry-rolled corn-based finishing diets on heifer performance, carcass characteristics, and manure characteristics..
, who reported no difference in carcass characteristics when SFC was replaced with WDGS.
Depenbusch et al., 2008.- Depenbusch B.E.
- Drouillard J.S.
- Loe E.R.
- Higgins J.J.
- Corrigan M.E.
- Quinn M.J.
Efficacy of monensin and tylosin in finishing diets based on steam-flaked corn with and without corn wet distillers grains with solubles..
observed lower HCW, DP, and LM area when WDGS was included in the diet, but all other carcass variables were not different. Marbling score, QG, and LM area also did not differ when SB was included in the diet as a replacement for corn (
Macken et al., 2004.- Macken C.N.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Effects of concentration and composition of wet corn gluten feed in steam-flaked corn-based finishing diets..
;
Block et al., 2005.- Block H.C.
- Macken C.N.
- Klopfenstein T.J.
- Erickson G.E.
- Stock R.A.
Optimal wet corn gluten and protein levels in steam-flaked corn-based finishing diets for steer calves..
). However, when associated with heavier carcasses, carcass characteristics such as 12th-rib fat thickness increased as SB was added to the diet in some studies (
Scott et al., 2003.- Scott T.L.
- Milton C.T.
- Erickson G.E.
- Klopfenstein T.J.
- Stock R.A.
Corn processing method in finishing diets containing wet corn gluten feed..
;
Domby et al., 2014.- Domby E.M.
- Anele U.Y.
- Gautam K.K.
- Hergenreder J.E.
- Pepper-Yowell A.R.
- Galyean M.L.
Interactive effects of bulk density of steam-flaked corn and concentration of Sweet Bran on feedlot cattle performance, carcass characteristics, and apparent total tract nutrient digestibility..
). A tendency (
P = 0.09) for greater YG for WDGS20 and SB20 than CON likely occurred because of the greater HCW of cattle consuming the corn-milling product diets, as HCW is a variable in the YG equation (
Chiputwa, 2010USDA. 2017. United States standards for grades of carcass beef. Pages 27782–27786 in No. (82)116. Agric. Market. Serv., USDA.
). Similar results were observed by
Domby et al., 2014.- Domby E.M.
- Anele U.Y.
- Gautam K.K.
- Hergenreder J.E.
- Pepper-Yowell A.R.
- Galyean M.L.
Interactive effects of bulk density of steam-flaked corn and concentration of Sweet Bran on feedlot cattle performance, carcass characteristics, and apparent total tract nutrient digestibility..
, as greater YG were associated with heavier carcasses when SB replaced SFC in the diet.
Table 4Effects of no fibrous corn-milling products or wet distillers grains with solubles, Sweet Bran, or both on finishing cattle carcass characteristics
a,bMeans within a row with different superscript letters differ, P < 0.05.
Quality grade and liver abscess scores were not different (
P ≥ 0.25) among treatments. However, the proportion of abscessed livers was numerically less for the corn-milling product diets than CON (19.5, 14.5, 12.2, and 11.2% for CON, WDGS20, SB20, and COMBO, respectively). Liver abscesses have been linked to intensive feeding strategies and are believed to be caused from ruminitis.
Haskins et al., 1967.- Haskins B.R.
- Wise M.B.
- Craig H.B.
- Barrick E.R.
Effects of levels of protein, sources of protein and an antibiotic on performance, carcass characteristics, rumen environment and liver abscesses of steers fed all-concentrate rations..
demonstrated that liver abscesses are more pronounced when cattle are fed highly fermentable concentrate diets such as the CON diet used in the present study. The numerical but not statistical difference in liver abscesses observed in this study is expected because it is historically challenging to delineate differences among treatments for binomial outcomes, such as the proportion of liver abscesses, in small pen research. Because liver abscesses are relatively infrequent, a statistical difference between treatments may have been observed with a larger sample size.
Calculated empty body fat did not differ (
P = 0.25), but empty BW of steers was greater (
P = 0.04) for SB20 and WDGS20 than COMBO and CON because of increased HCW of cattle consuming SB20 and WDGS20 (
Table 5). Adjusted final BW was not different (
P = 0.91). Performance-calculated NE
m and NE
g did not differ (
P = 0.13) between treatments but were numerically less for WDGS20, SB20, and COMBO compared with CON. The ratio of observed versus expected NE
m and NE
g was less (
P ≥ 0.02) for WDGS20, SB20, and COMBO than CON. The ratio of observed versus expected NE ranged from 0.98 to 1.03 in the present study and suggests that cattle performed as expected given the dietary energy density. Lower observed versus expected NE for cattle consuming the diets containing corn-milling products compared with CON indicates that perhaps the tabular values reported by
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle. 8th rev. ed. Natl. Acad. Press.
may overestimate the energy value of diets including corn-milling products such as WDGS and SB and underestimate the energy value of diets without corn-milling products. Again, because the ratio of observed versus expected NE is calculated by comparing performance-calculated NE to dietary NE projected from tabular values, it is important to note that this comparison is not as valuable if the dietary NE projected from
Chiputwa, 2010NASEM (National Academics of Science, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle. 8th rev. ed. Natl. Acad. Press.
does not accurately represent the true energy density of the diet. Furthermore, despite statistical differences among treatments, the numerical differences for observed versus expected NE are small and influenced by slight changes in performance or dietary energy concentrations. Therefore, caution should be taken when interpreting the relationship between observed versus expected NE.
Table 5Effects of no fibrous corn-milling products or wet distillers grains with solubles, Sweet Bran, or both on empty body fat, empty BW, adjusted BW, and performance-calculated energy
a,bMeans within a row with different superscript letters differ, P < 0.05.