Two experiments were conducted to evaluate the effects of decreasing digestibility of a finishing diet by replacing dry rolled corn (DRC) with corn bran, or a combination of corn bran and steep, on cattle performance and nitrogen mass balance in open feedlots. Replacement of DRC with bran had no impact on performance when steep was included in the finishing diets at 15% DM. Feeding bran and steep, in combination, was an effective means of reducing N losses in winter, as well as maintaining cattle performance throughout the year

Erickson, Galen E.

Klopfenstein, Terry J.

Macken, Casey N.

Sayer, Kristi M.

Vander Pol, Kyle J.

English

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Nebraska Beef Cattle Reports Animal Science Department January 2005 Effects of Corn Bran and Corn Steep Inclusion in Finishing Diets on Cattle Performance and Nitrogen Mass Balance Kristi M. Sayer University of Nebraska-Lincoln Galen E. Erickson University of Nebraska-Lincoln, gerickson4@unl.edu Terry J. Klopfenstein University of Nebraska-Lincoln, tklopfenstein1@unl.edu Kyle J. Vander Pol University of Nebraska-Lincoln Casey N. Macken University of Nebraska-Lincoln Follow this and additional works at: https://digitalcommons.unl.edu/animalscinbcr  Part of the Animal Sciences Commons Sayer, Kristi M.; Erickson, Galen E.; Klopfenstein, Terry J.; Vander Pol, Kyle J.; and Macken, Casey N., "Effects of Corn Bran and Corn Steep Inclusion in Finishing Diets on Cattle Performance and Nitrogen Mass Balance" (2005). Nebraska Beef Cattle Reports. 175. https://digitalcommons.unl.edu/animalscinbcr/175 This Article is brought to you for free and open access by the Animal Science Department at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Nebraska Beef Cattle Reports by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 2005 Nebraska Beef Report — Page 54Effects of Corn Bran and Corn Steep Inclusionin Finishing Diets on Cattle Performance andNitrogen Mass Balance10.6% (2002 Nebraska Beef Report, pp54-57).Corn steep is a by-product of thewet corn milling industry and hasbeen shown to have a higher energyvalue than dry rolled corn (DRC). Itis a combination of both distillerssolubles and steep liquor. The opti-mal inclusion level of steep in fin-ishing diets was determined to be15% of diet DM, when bran wasalso included in the diet at 15% or30% (1998 Nebraska Beef Report, pp69-71). Feed efficiency was im-proved 9.3% when steers were fed acombination of bran and steep.Steep and bran are normally com-bined in the production of wet corngluten feed, which is becoming acommon feed in feedlot diets. Theobjectives of this study were toevaluate the effect on cattle perfor-mance and N mass balance ofreplacing DRC with corn bran andcorn steep in finishing diets.ProcedureCattle PerformanceIn the first experiment(WINTER), 128 steer calves (693 +29 lb) were fed 167 days, fromNovember 2002 to April 2003, andin the second experiment (SUM-MER), 256 yearling steers (806 + 31lb) were fed for 126 days, from Mayto September 2003. Steers werestratified by weight and assignedrandomly to one of four dietarytreatments.The control (CON) diet was for-mulated to provide a typical dryrolled corn-based diet (Table 1).Corn bran then replaced DRC at30% diet DM (30/0), similar to pre-vious studies (2002 Nebraska BeefReport, pp 54-57, 2003 Nebraska BeefReport, pp 54-58). Bran and steepreplaced DRC and molasses at 30%and 15% (DM basis), respectivelyKristi M. SayerGalen E. EricksonTerry J. KlopfensteinKyle J. Vander PolCasey N. Macken1SummaryTwo experiments were conducted toevaluate the effects of decreasing diges-tibility of a finishing diet by replacingdry rolled corn (DRC) with corn bran,or a combination of corn bran andsteep, on cattle performance and nitro-gen mass balance in open feedlots.Replacement of DRC with bran had noimpact on performance when steep wasincluded in the finishing diets at 15%DM. Feeding bran and steep, in com-bination, was an effective means ofreducing N losses in winter, as well asmaintaining cattle performancethroughout the year.IntroductionLess than 15% of dietary nitro-gen (N) is retained by feedlot cattle(1996 Nebraska Beef Cattle Report, pp74-77). The other 85% is excretedand can be lost by volatilization. Byincreasing the amount of carbon inthe manure, it is possible to trapmore N in manure and thus volatil-ize less N.One way to increase the amountof organic matter (OM) in themanure is to increase the amount ofhind gut fermentation by loweringdiet digestibility (1996 Nebraska BeefReport, pp 74-77). Corn bran is ahighly digestible fiber source that iseffective in increasing the amountof OM and trapping more N inmanure. N losses were reduced by20.4% in winter, when bran wasincluded at 30% diet DM; however,feed efficiency was reduced byTable 1. Composition of dietary treatments for WINTER and SUMMER trials (% DMbasis).Ingredient CON 30/0 30/15 45/15Dry rolled-corn 75 45 35 20Corn Silage 15 15 15 15Corn Bran — 30 30 45Steep — — 15 15Molasses 5 5 — —Dry SupplementLimestone 1.56 1.65 1.66 1.66Urea 1.50 0.99 0.10 —Blood Meal 0.15 0.75 — —Feather Meal 0.15 0.75 — —Fine Ground Corn 1.08 0.27 2.70 2.80Salt 0.30 0.30 0.30 0.30Tallow 0.15 0.15 0.15 0.15Beef Trace Mineral 0.05 0.05 0.05 0.05Potassium Chloride 0.02 0.05 0.05 0.05Rumensin Premix 0.018 0.018 0.018 0.018Tylan Premix 0.013 0.013 0.013 0.013Vitamin Premix 0.01 0.01 0.01 0.01Nutrient Composition (%)CPa 13.7 13.4 14.0 14.2DIPb 8.9 9.8 9.5 10.4Calciumc 0.70 0.70 0.70 0.70Phosphorusc 0.32 0.26 0.47 0.44aCalculated based on average CP analysis of feedstuffs for WINTER and SUMMER trial.bDIP = degradable intake protein.cCalculated based on tabular values.Page 55 — 2005 Nebraska Beef ReportWINTER trial.For both trials, feed refusals werecollected and sampled. Pens werecleaned approximately every 28days during the WINTER and every42 days during the SUMMER.Manure was piled on the cementapron, sampled, weighed and thenpiled in windrows in the compostyard.Feed sources were sampledmonthly and analyzed for ash, CP,and DM content. N intake was cal-culated based on analyzed dietaryN sources, multiplied by DMI andcorrected for feed refusals. Retainedsteer N was calculated using theenergy and protein equation foundin the NRC (1996). N excretion wasdetermined by subtracting N reten-tion from N intake. The DM digest-ibility of the CON diet was 79% andthe by-product diets were reportedas 73.7%, 72.8%, and 72.6% DMdigestibility for the 30/0, 30/15,and 45/15 diets respectively in the2005 Nebraska Beef Cattle Report,pp 39-41.Total N loss was calculated on alb/steer basis. Excreted N minusrunoff N and manure N equals totalN lost. The percentage of N lost wascalculated as N lost divided by Nexcreted. All data were analyzedusing the PROC MIXED proceduresin SAS.ResultsFeedlot PerformanceCattle were finished to similarendpoints, with no differences inhot carcass weight or 12th rib fat(Table 2). In WINTER, cattle fedCON diets tended to eat less thancattle on byproduct diets (23.2 lb/day vs. 24.3 lb/day, P = 0.06), how-ever, no differences in final weightor feed conversions were detected(P > 0.05; Table 2). These data tendto contradict previous researchwhere cattle on 30/0 diets hadlower feed conversions.Cattle fed during the SUMMER(Table 3) were also finished toTable 2. Effects of dietary treatment on steer performance during WINTER trial.TreatmentaItem CON 30/0 30/15 45/15 SEMb F-TestcDMI, lb/day 23.2 24.3 25.1 23.7 0.43 0.06ADG, lb 3.70 3.80 3.90 3.70 0.08 0.22Feed:Gaind 6.27 6.39 6.42 6.44 0.14 0.56Hot Carcass Weight, lb 826 835 848 824 9.18 0.2712th rib fat, in 0.59 0.53 0.55 0.56 0.03 0.67Marbling scoree 539 512 535 551 16.93 0.46aTreatments: CON = dry rolled corn-based diet with no byproduct inclusion; 30/0 = dryrolled corn replaced with 30% bran and 0% steep; 30/15 = dry rolled corn and molassesreplaced with 30% bran and 15% steep; 45/15 = dry rolled corn and molasses replacedwith 45% bran and 15% steep.bStandard error of the mean.cData were analyzed using a protected F-test where numbers represent P-value forvariation due to treatment.dAnalyzed as Gain:feed.eMarbling score: 400 = slight0; 450 = slight50; 500 = small0; 550 = small50; etc.Table 3. Effects of dietary treatment on steer performance during SUMMER trial.TreatmentaItem CON 30/0 30/15 45/15 SEMb F-TestcDMI, lb/day 24.0e 25.6f 26.0f 25.4f 0.24 <0.01ADG, lb 3.50 3.46 3.76 3.63 0.08 0.07Feed:Gain 6.89e 7.43f 6.92e 7.02e 0.14 0.05Hot Carcass Weight, lb 788 784 806 799 7.21 0.1512th Rib Fat,in 0.48 0.52 0.50 0.49 0.03 0.74Marbling Scoree 500 501 515 484 8.51 0.11aCON = dry rolled corn based diet with no byproduct inclusion; 30/0 = dry rolled cornreplaced with 30% bran and 0% steep; 30/15 = dry rolled corn and molasses replacedwith 30% bran and 15% steep; 45/15 = dry rolled corn and molasses replaced with 45%bran and 15% steep.bStandard error of the means.cData were analyzed using a protected F-test where numbers represent P-value forvariation due to treatment.dMarbling score: 400 = slight0; 450 = slight50; 500 = small0; 550 = small50; etc.efMeans within row with different superscripts differ.(30/15), to evaluate the effect ofsteep. The final treatment included45% bran and 15% steep (45/15) ona DM basis, to try and furtherincrease the amount of OM in themanure. Cattle were adapted todiets over a 21-day step up period.During the first 67 days of theWINTER trial, cattle were fed dietscontaining 6% supplement. Dietswere balanced for metabolizableprotein. WINTER calves wereimplanted with Synovex S® andre-implanted with Revalor S®, andSUMMER yearlings were implant-ed with Revalor-S®.Following harvest, data wererecorded on hot carcass weight,12th rib fat, marbling and yieldgrade. Final weights were calcu-lated based on a 63% commondressing percentage. DM intake,ADG, and feed/gain were calcu-lated.Nutrient BalanceThe WINTER experiment wasconducted using 16 open feedlotpens with a stocking density of 344ft2 per steer and 8 steers per pen.When rainfall occurred, runoff wascollected in retention ponds belowthe pens. Precipitation amount wasmeasured using a rain gauge, andthe effluent was drained and quan-tified using an air bubble flowmeter (ISCO, Lincoln, Nebraska).Samples of the effluent were col-lected and analyzed for DM, OM,and total N content.The SUMMER experiment wasconducted using 24 open feedlotpens. Sixteen of the pens were thesame pens used in the WINTERexperiment. The other 8 pens had16 steers per pen, with a stockingdensity of 328 ft2 per steer. Runoffcollection was similar to the (Continued on next page)2005 Nebraska Beef Report — Page 56Table 4. Effects of dietary treatment on nitrogen mass balance during WINTERexpressed in lb/steer.TreatmentaItem CON 30/0 30/15 45/15 SEMb F-TestbN intake 91.2g 89.5g 97.6h 93.5gh 1.5 0.02N retentionc 12.5 12.8 13.2 12.4 0.2 0.24N excretiond 78.8g 76.6h 84.4i 81.2gi 1.3 0.01Manure N 28.6g 37.8h 40.7h 52.0i 3.5 <0.01Run-off 0.20 0.05 0.12 0.01 0.06 0.20N loste 50.0g 38.8hi 43.7gh 29.2i 5.1 0.01N loss, %f 63.7g 50.7h 51.8h 35.8i 9.0 0.01DM removed 2379g 2523g 2732g 3859h 302 0.02OM removed 605g 928h 935h 1269i 70 <0.01aCON = dry rolled corn-based diet with no by-product inclusion; 30/0 = dry rolled cornreplaced with 30% bran and 0% steep; 30/15 = dry rolled corn and molasses replacedwith 30% bran and 15% steep; 45/15 = dry rolled corn and molasses replaced with 45%bran and 15% steep.bData were analyzed using a protected F-test where numbers represent P-value forvariation due to treatment.c Calculated using the NRC net protein and net energy equations.dCalculated as N intake - N retention.eN lost = N excretion - Manure N - Runoff N.fCalculated as N lost divided by N excretion.ghiMeans within row with different superscripts differ.Table 5. Effects of dietary treatment on nitrogen mass balance during SUMMER,expressed as lb/steer.TreatmentaItem CON 30/0 30/15 45/15 SEM F-TestbN intake 75.2g 83.3h 81.3hi 80.1i 0.7 <0.01N retentionc 11.2g 10.9g 12.0h 11.5gh 0.2 0.05N excretiond 64.1g 72.4h 69.3i 68.6i 0.7 <0.01Manure N 22.3g 29.8h 28.7h 29.2h 1.5 0.01Run-off 2.29 1.65 3.25 1.47 0.5 0.09N loste 40.7 41.8 39.0 38.6 2.2 0.69N loss, %f 63.5 57.8 56.2 56.4 6.6 0.13DM removed 1844 2346 2221 2489 200 0.16OM removed 395g 593h 575h 615h 29 <0.01aCON = dry rolled corn-based diet with no by-product inclusion; 30/0 = dry rolled cornreplaced with 30% bran and 0% steep; 30/15 = dry rolled corn and molasses replacedwith 30% bran and 15% steep; 45/15 = dry rolled corn and molasses replaced with 45%bran and 15% steep.bData were analyzed using a protected F-test where numbers represent P-value forvariation due to treatment.cCalculated using the NRC net protein and net energy equations.dCalculated as N intake - N retention.eN lost = N excretion - Manure N - Runoff N.fCalculated as N lost divided by N excretion.ghiMeans within row with different superscripts differ.similar endpoints, with no differ-ences detected in final weight or12th rib fat. Cattle on the CON diethad lower DMI then those on theby-product diets (24.0 lb/day vs.25.7 lb/day, P<0.01). Cattle fed the30/0 diet had lower (P < 0.05) feedconversions than other treatments(Table 3); however, when corn steepwas added to the diet, feed conver-sions were similar to the CON.These data support the theory thatsteep helps cattle maintain perfor-mance when bran is included in thediet, possibly because of the addi-tional energy provided by steep.Nutrient BalanceManure N content was higherfrom cattle on the 30/0, 30/15, and45/15 diets (P < 0.05) than manureN from the CON fed cattle (Table 4).The 45/15 treatments had the low-est (P < 0.05) percentage of N lostand had the highest amount of OMremoved from the pen floor. This issimilar to what has been observedin previous research (1996 NebraskaBeef Cattle Report, pp 74-77). The45/15 treatments reduced N lossesby 43.9%, when compared to theCON diet (P < 0.05).During the SUMMER trial (Table5), no differences were detected inthe percentage of N lost amongtreatments (averaging 60.1%).Manure N content and the amountof OM removed from the pen werehigher for the by-product diets thanthe CON diet (P < 0.05).Temperature and moisture bothaffect the amount of N volatilized.During the WINTER trial, thetemperature averaged 33.9oF, withonly 3.74 inches of rainfall; how-ever, the SUMMER trial averaged69.4oF, with 12.20 inches of rainfall.The higher N losses during theSUMMER can be attributed to thesehigher temperatures and possiblyto the higher rainfall. As with otherstudies (2003 Nebraska Beef Report,pp 54-58, 2002 Nebraska Beef Report,pp 54-57), reducing N lossesthrough feeding corn bran andincreasing OM on the pen floorsurface was only effective in theWINTER.Feeding bran and steep, in com-bination, was an effective means ofreducing N losses in winter, as wellas maintaining cattle performancethroughout the year.1Kristi M. Sayer, graduate student,Galen E. Erickson, assistant professor,Terry J. Klopfenstein, professor, AnimalScience, Lincoln, Kyle J. Vander Pol,research technician, Casey N. Macken,former research technician, Lincoln.

Effects of Corn Bran and Corn Steep Inclusion in Finishing Diets on Cattle Performance and Nitrogen Mass Balance

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Effects of Corn Bran and Corn Steep Inclusion in Finishing Diets on Cattle Performance and Nitrogen Mass Balance

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