Effects of feeding time (800 vs 1400) and sprinkling on feedlot performance, body temperature, and mound microclimate were examined to determine their usefulness in reducing heat stress of feedlot steers. Feed conversion was improved overall for steers with access to sprinklers. Body temperature, early in the finishing period, was reduced by both sprinkling and afternoon feeding relative to steers fed at 800 h without access to sprinklers . Overall water intake was greater for steers fed at 800 without sprinkling than any other treatment

Davis, Shane

Mader, Terry L.

English

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Nebraska Beef Cattle Reports Animal Science Department January 2002 Effect of Altered Feeding and Sprinkling on Performance and Body Temperature of Steers Finished in the Summer Shane Davis University of Nebraska-Lincoln Terry L. Mader University of Nebraska-Lincoln, tmader1@unl.edu Follow this and additional works at: https://digitalcommons.unl.edu/animalscinbcr  Part of the Animal Sciences Commons Davis, Shane and Mader, Terry L., "Effect of Altered Feeding and Sprinkling on Performance and Body Temperature of Steers Finished in the Summer" (2002). Nebraska Beef Cattle Reports. 252. https://digitalcommons.unl.edu/animalscinbcr/252 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. Page 61 — 2002 Nebraska Beef ReportSprinkling cattle is an effectivemethod of altering animal responseunder conditions conducive to heatstress. Cooling cattle by use of sprin-klers maintains dry matter intake underhot environmental conditions andeffectively buffers a rise in body tem-perature which can lead to death. Whencooling strategies are employed, theyshould be consistent and remain unin-terrupted until weather conditions nolonger pose any danger.1Shane Davis, graduate student; Terry Mader,professor, Animal Science, Northeast Researchand Extension Center, Norfolk, Neb.; JohnGaughan, Lecturer, University of Queensland-Gatton, Australia.106105140130120101Rectal temperature, oF800900100011001200130014001500160017001800190020002100220023002400 100200300400500600700Time of hay, hourDWNWFigure 5. Comparison of rectal temperature of heifers prior to and after missing a sprinklingperiod. Before vs afer x time interaction (P<.01). *Values within a time differ (P<.05).Effect of Altered Feeding and Sprinkling onPerformance and Body Temperature of SteersFinished in the Summer(Continued on next page)Shane DavisTerry Mader1Sprinkling feedlot cattle toreduce heat stress improved over-all feed conversion, reduced bodytemperature, and reduced waterintake.SummaryEffects of feeding time (800 vs 1400) and sprinkling on feedlot performance,body temperature, and mound micro-climate were examined to determinetheir usefulness in reducing heat stressof feedlot steers. Feed conversion wasimproved overall for steers with accessto sprinklers. Body temperature, earlyin the finishing period, was reduced byboth sprinkling and afternoon feedingrelative to steers fed at 800 h withoutaccess to sprinklers . Overall waterintake was greater for steers fed at 800without sprinkling than any other treat-ment.IntroductionIn the last decade, heat related pro-duction losses in Nebraska surpassed$100 million as a direct result of fourheat waves in the years 1992, 1995,1997 and 1999. In previous NebraskaBeef Reports (2001), we reportedchanges in body temperature and per-formance of steers subjected to eitheraltered feeding regimens or watersprinkling, however additive benefitsof these systems were not evaluated.Thus, this study was designed to exam-ine altered feeding time with or withoutwater sprinkling on body temperatureand performance of feedlot steers.ProcedureOne hundred ninety-two crossbred(English x Continental) steers werereceived at the Northeast Research andExtension Center Feedlot, Concord, Neb.and processed according to normalprocedures. Near the beginning ofsummer animals were weighed and ran-domly assigned to one of 24 pens (eighthd/pen). Treatments were assigned topens using a factorial design, which2002 Nebraska Beef Report — Page 62consisted of feeding time (800 [AM] vs1400 hours [PM]) and water sprinkling(none [DRY] vs sprinkling [WET]).Cattle on the PM feeding regimen werefed at 1400 hours and their bunks weremanaged such that there was no feedavailable to them between the hours of800 - 1400. Sprinkling was accomplishedvia overhead sprinklers controlled bytimers. Sprinkler placement allowedcattle to be sprinkled as well as ad-equately wetting the mound surface.Sprinklers operated 20 minutes every1.5 hours between 1000 and 1730 ondays when predicted maximum THI >77.Predicted maximum THI was made us-ing a linear relationship derived fromdata collected (July and August of previ-ous two years) by a weather station in thecenter of the feeding facility. Linear re-lationships between maximum daily THIand THI at 0700, 0800, and 0900 hourswere determined. Temperature-humid-ity index at 900 hours had the best rela-tionship. The equation was programmedinto a weather station located in thecenter of the facility. When THI at 900hours was greater then or equal to 68, asolenoid connected to the water faucetsupplying the sprinklers was opened,allowing the timer to operate the sprin-klers.All cattle were managed similarlyfrom day 0 - 21 of the trial. During thistime, no sprinkling was done and feedwas delivered at 800 h. To obtain accu-rate baseline measurements all cattle weremanaged similarly (no sprinkling and800 hour feeding).Feed and water intakes were recordeddaily. Body weights were obtained ondays 0, 21, 56 and 83 (termination of thetrial). On the morning of day 84, steerswere transported to a commercial slaugh-ter facility where hot carcass weight,marbling score, 12th rib fat thickness,liver abscess scores, and quality andyield grade were obtained. On days one- four, 31 - 35, and 58 - 63 tympanictemperatures (an indicator of core bodytemperature) were obtained from six hd/sprinkling-feeding time combination(TRT). Tympanic temperatures wereobtained using Stowaway® XTI dataloggers secured to the ear using tape andgauze. Thermistors attached to the datalogger were inserted down the ear canalsuch that they were near the tympanicmembrane. Temperature was recordedevery 15 min and compiled into hourlyreadings. Microclimatic conditions (tem-perature and relative humidity) of themound were monitored and recordedusing HOBO Pro® data loggers. Log-gers were attached at heights of 6 and30 in to fence post that bisected themounds. Loggers at 6 in. recorded ambi-ent temperature and soil temperature at adepth of 1 in. via an attached probe.Ambient temperature and RH wererecorded by the logger at 30 in., thisallowed for THI to be calculated at thisheight.Statistical analysis for performance,carcass, tympanic temperature andmound microclimate was done usingGeneral Linear Models procedures. Thestatistical model for performance dataincluded feeding time, sprinkling, andfeeding time x sprinkling with day 0 - 21ADG being used as a covariant. Carcassdata were analyzed similarly except nocovariant was used. Tympanic tempera-ture and mound microclimate data wereanalyzed using the repeated statement(to account for time of day) in SAS withthe model including feeding time, sprin-kling, and feeding time x sprinkling, dayincluded in the model. Data were com-pared within time of day with P < 0.05used to determine significance.ResultsClimatic conditions for days 21 - 83are summarized in Table 1. Sprinklersoperated on 31 of 63 days during theTRT period. Ninety percent ofthe days (28 of 31) the sprinklers oper-ated, maximum THI was greater thanor equal to 77. Temperature-humidityindex exceeded 77 on 7 of the 32 non-sprinkling days of the treatment period.The equation used to predict maximumTHI was accurate between 82 - 90% ofthe time.During days 0 - 21, similar perfor-mance was found among TRT (Table 2).Also, for the 21 - 56 day performance,ADG, feed conversion, and DMIremained similar among TRT. Howevera feeding time x sprinkling interaction(P < 0.05) was found for water intake.Water intakes were 10 and 13% greaterfor AM/DRY steers than PM/DRY andPM/WET steers, respectively. For days56 - 83 ADG and daily DMI remainedunaffected by TRT and averaged 3.47 lband 21.39 lb, respectively. Feed conver-sion during this time was affected bysprinkling (P = 0.06); steers in pens withsprinklers were 15 % more efficient thansteers in pens without sprinklers. Thisdifference resulted in an overall feedconversion improvement of 5% for steersin pens with sprinklers. Water intakesTable 1. Climatic conditions during the 21 day common management and 63 day treatmentperiod. Values represent the mean + standard error.Item Mean Maximum MinimumDays 0 - 21Temperature, oF 70.3 + 1.6 81.3 + 1.9 59.8 + 1.4Relative humidity, % 61.9 + 2.6 82.8 + 2.0 40.1 + 3.0THIa 66.9 + 1.1 73.5 + 1.0 59.5 + 1.2Days 22 - 56Temperature, oF 73.1 +   .9 82.4 + 1.1 63.3 + 1.0Relative humidity, % 73.3 + 1.0 90.0 +   .6 53.0 + 1.7THIa 70.4 +   .8 76.3 +   .8 62.9 +   .9Days 57 - 83Temperature, oF 73.0 + 1.0 82.9 + 1.5 63.6 +   .9Relative humidity, % 78.2 + 1.5 92.6 +   .5 58.7 + 2.8THI 70.7 +   .8 77.0 + 1.0 63.2 +   .8Days 22 - 83Temperature, oF 73.0 +   .7 82.6 +   .9 63.4 +   .7Relative humidity, % 75.4 +  .9 91.1 +   .4 55.3 + 1.6THI 70.5 +   .6 76.6 +   .6 63.0 +   .6aTHI = Temperature-Humidity Index = Temperature - (.55 - (.55 x (Relative humidity/100))) x(Temperature - 58)Page 63 — 2002 Nebraska Beef Reportfor days 56 - 83 continued to be differentin AM/DRY steers (feeding time x sprin-kling, P < .05). These steers averaged13% greater water intakes during days56 - 83 and 11% greater overall. Othermeasures of performance remainedunaffected by TRT.Carcass traits of the TRTs are pre-sented in Table 3. All TRTs had similarHCW, dressing percentage, QG, YG andfat thickness. However, marbling scorewas affected by a feeding time x sprin-kling interaction (P < .05) with AM/DRY steers averaging 7% higher than allother steers.Tympanic temperatures during thepre-TRT period (days 0 - 21) were notaffected by TRT (data not shown), thusdifferences in subsequent TT measure-ments may be viewed as a direct result ofTRT.Tympanic temperatures on days 30 -32 were affected by a Feeding time xSprinkling x Time of day interaction (P< 0.05). Steers fed in the morning with-out access to sprinklers (AM/DRY) hadhigher TT than PM/DRY steers at alltimes sampled. Likewise, AM/DRYsteers had higher (P < 0.05) TT than PM/WET at all times except 1500 - 1600 and1900 - 200 h, and were higher (P < 0.05)than AM/WET steers at all times except400 - 800 h. Differences between AM/WET, PM/DRY and PM/WET wereminimal and variable and are best viewedby Table 4. With the exception of 800 h,cattle on TRTs designed to minimizeheat stress had similar (P > 0.05) TTfrom 900 - 1400 h. On hour after feeding(1500 h ) PM/WET steers had similarTT to AM/DRY, but both were higherthan AM/WET and PM/DRY. Thesedifferences may be due to the fact thatPM/WET steers were more comfortablebecause they had been sprinkled and hadnot experienced metabolic heat loadassociated with eating and thereforetheir increased TT may be attributed toan eating event.Sprinkling x time of day interaction(P < 0.01) also affected TT on days 30 -32 (Figure 2). During this time, TT ofsprinkled steers was lower at 1400 and1600 - 1900 h than non-sprinkled cattle.Maximum differences in TT of theseanimals was at 1800 h where DRY steersTable 2. Effect of altered feeding time (800 [AM] vs 1400 [PM] h) with (WET) and without (DRY)sprinkling on feedlot performance of yearling steers.TreatmentsItem AM/DRY AM/WET PM/DRY PM/WET SEMBody weight, lbsDay 0 936.5 933.4 932.3 936.3 2.2Day 21 1012.7 1009.4 1008.6 1012.5 2.2Day 83 1239.1 1249.7 1236.0 1246.8 8.8Average daily gain, lb/dDay 0 - 21a 3.83 3.53 3.75 3.42 .22Day 22 - 83 3.64 3.86 3.64 3.79 .13Dry matter intake, lb/dDay 0 - 21 20.21 20.03 19.88 20.98 .40Day 22 - 83 21.38 20.94 20.94 21.31 .46Feed:gainDay 0 - 21 5.67 5.65 5.73 5.95 .15Day 22 - 83b 5.89 5.45 5.78 5.64 .16Water intake, gal/dDay 0 - 21 7.13 7.14 6.65 6.64 .74Day 22 - 83c 10.03d 9.10e 8.97e 9.03e .11aUsed as a covariate for subsequent performance (BW, gain, DMI and feed:gain) from days 22 - 83bSprinkling effect, P < .10cFeeding time x Sprinkling interaction, P < .05deValues within a row with different superscripts differ, P < .05Table 3. Effect of feeding time (800 [AM] vs. 1400 [PM] h) with (WET) and without(DRY) sprinkling on carcass characteristics of yearling steers.TreatmentsItem AM/DRY AM/WET PM/DRY PM/WET SEMHot carcass wt., lbs 771.0 768.5 766.6 761.7 4.4Dress, % 62.1 61.6 61.9 61.3 .412th rib fat, in .40 .47 .43 .44 .04Yield grade 2.00 2.11 2.11 2.15 .081s and 2s, % 79.2 70.21 70.21 68.75Marbling scoreab 550.6c 519.3d 505.5d 519.6d 10.5Choice, % 75.0 57.5 63.8 66.7aMarbling score: 500 = Small 0 (low Choice)bFeeding time x Sprinkling interaction (P < .05)cdValues in a row with different superscripts differ (P < .05)Table 4. Effect of feeding time (800 [AM] vs. 1400 [PM] h) with (WET) and without (DRY)sprinkling on tympanic temperature of yearling steers on days 30 - 32.Time of day Treatments0800 AM/DRYa AM/WETab PM/DRYb PM/WETb0900 - 1400 AM/DRYa AM/WETb PM/DRYb PM/WETb1500 AM/DRYa AM/WETb PM/DRYb PM/WETa1600 AM/DRYa AM/WETc PM/DRYbc PM/WETab1700 - 1900 AM/DRYa AM/WETc PM/DRYbc PM/WETb2000 AM/DRYa AM/WETb PM/DRYb PM/WETab2100 AM/DRYa AM/WETb PM/DRYb PM/WETa2200 - 0200 AM/DRYa AM/WETb PM/DRYb PM/WETab0300 AM/DRYa AM/WETb PM/DRYb PM/WETb0400 AM/DRYa AM/WETab PM/DRYb PM/WETbc0500 AM/DRYa AM/WETa PM/DRYb PM/WETab0600 AM/DRYa AM/WETab PM/DRYbc PM/WETab0700 AM/DRYa AM/WETbc PM/DRYc PM/WETababcTreatments in a row differ (P < .05) (Continued on next page)2002 Nebraska Beef Report — Page 64were 1oF higher than WET steers. Thesefindings suggest provision of cattle withsprinklers moderated body temperatureduring the hottest part of the day, pre-venting them from being placed at riskfor heat related production losses.When TT were obtained later in thefeeding period (days 61 - 62) there wasa feeding time x time of day interaction(P < 0.001). Steers fed in the afternoonhad higher TT than those fed in themorning between 1500 - 1900 h (Figure2). These differences suggest PM steershad higher TT due to increased meta-bolic heat load associated with eating.Dry matter intakes of these steers duringthis time were not different (data notshown), however the time in which theAM steers consumed their meal mayhave altered their TT. These steers hadnumerically higher TT between 800 -1100 h. This may be due to a shift ineating pattern such that a larger per-centage of their diet was consumed atnight. If this is the case, this would be aself-imposed, adaptive mechanism bythese steers. Steers fed in the afternoonon the other hand would have been pre-viously conditioned and adapted to con-suming feed in the middle of the day. Soalthough they did have higher TT, thismay not be indicative of greater heatstress.Mound soil temperature as collectedon days 31 - 33 are presented in Table 5.Sprinkling lowered overall soil tempera-ture (P < 0.001) at all times sampled(sprinkling x time of day interaction, P <0.01). Differences between WET andDRY soil temperatures were minimizedon days 30 - 32 at 730 h. At this time soiltemperatures were 5.8oF lower (P < .05)for WET vs DRY mounds. Differencesin soil temperature between WET andDRY mounds were maximized at 1730hours where WET mounds were 12.9oFcooler (P < 0.05) than DRY mounds.The opportunity for conductive heatexchange between the soil and animaldepends on the temperature differential.Thus, wet mounds would be more con-ducive for conductive cooling for theanimal.Temperatures at 6 and 30 inches abovethe mound on days 30 - 32 (Table 5)were also affected by sprinkling (P <0.01) and a sprinkling x time of day106105104103102101100Temperature, oF800900100011001200130014001500160017001800190020002100220023002400 100200300400500600700Time of day, hourAM/DryAM/WetPM/DryPM/WetFigure 1. Effect of altered feeding regime (AM vs PM) and sprinkling (WET vs DRY) on tympanictemperatures of stress on days 31 - 33. Feeding time x sprinkling x time of day interaction(P<.05).105104103102101100Temperature, oF800900100011001200130014001500160017001800190020002100220023002400 100200300400500600700Time of day, hourDryWetFigure 2. Effect of sprinkling on tympanic temperature of stress on days 31 - 33. Sprinkling x timeinteraction (P<.01). *Values within a time differ (P<.05).interaction (P < 0.01). No differenceswere observed at 730 hours at either 6 or30 inches above the mound, however at1000 hours, temperatures at 6 and 30inches above WET mounds were 3.8and 1.8oF cooler (P < 0.05), respec-tively. Temperatures 6 inches aboveWET mounds remained 4.6, 5.2, 4, and1.2oF cooler than DRY mounds at 1230,1500, 1730, and 2000 hours, respec-tively. While temperatures 30 inchesabove the mound were 3.3, 3.2, and1.8oF cooler (P < 0.05) than DRY moundsat 1230, 1500 and 1730 hours, respec-tively. Differences in RH 30 inches abovethe mounds on days 30 - 32 were evidentbetween 730 - 1730 h (sprinkling x timeof day, P < .05). Differences (P < .05)Page 65 — 2002 Nebraska Beef Reportacross these times averaged 12% andranged from 4% at 730 h to 18% at 1500h. Despite increasing RH, THI was low-ered (P < .05) in response to sprinkling.At 1000, 1230, and 1500 h, THI waslower (sprinkling x time of day, P < .05)30 inches above WET mounds. Increasedrelative humidity accompanied by sprin-kling can theoretically reduce the evapo-rative heat exchange mechanisms of thesteers. However, the associated decreasesin soil and ambient temperature wouldallow for greater animal comfort as wellas increased conductive heat exchange.The decrease in body temperature ob-served in this study associated with sprin-kling supports this theory.Microclimatic conditions of themounds obtained on days 30 - 32 and 61- 62 (data not shown), collectively sug-gest that sprinkling alters the micro-climatic profile of the sprinkled areamaking it conducive to greater heatflow away from the animal during hotenvironmental conditions. Althoughsprinkling did increase RH, animal com-fort, as defined by THI, was improvedin areas that were sprinkled. Bothsprinkling and altering feeding timecan decrease susceptibility of feedlotcattle to heat stress by lowering bodytemperature. Sprinkling cattle increasesoverall animal performance.1Shane Davis, graduate student; Terry Mader,professor, Animal Science, Northeast Researchand Extension Center, Concord, Neb.Table 5. Effect of sprinkling on microclimatic conditions of the mound during days 30 - 32.Values represent least square mean + standard error.Time of day, hItem 730 1000 1230 1500 1730 2000Temperature, oFSoilaDRY 78.1 + .4b 84.0 + .5b 91.1 + .7b 93.1 + .7b 95.0 + .6b 91.6 + .4bWET 72.3 + .4c 77.7 + .5c 83.0 + .7c 82.3 + .7c 82.1 + .6c 80.0 + .4c6 inchesaDRY 75.5 + .4 84.2 + .5b 91.5 + .7b 92.8 + .7b 91.6 + .6b 85.7 + .4bWET 75.1 + .4 80.4 + .5c 86.9 + .7c 87.6 + .7c 87.6 + .6c 84.5 + .4c30 inchesaDRY 74.8 + .4 83.1 + .5b 90.6 + .7b 91.8 + .7b 90.3 + .6b 85.3 + .4WET 74.4 + .4 81.3 + .5c 87.3 + .7c 88.6 + .7c 88.1 + .6c 84.8 + .4Relative humidity, %30 inchesaDRY 85.4 + 1.1b 68.9 + .6b 55.9 + 1.4b 54.9 + 1.2b 58.6 + 1.4b 71.5 + 1.2WET 88.6 + 1.1c 75.9 + .6c 64.6 + 1.4c 64.6 + 1.2c 66.4 + 1.4c 74.0 + 1.2Temperature-humidity indexd30 inchesaDRY 73.3 + .2 78.7 + .2b 82.4 + .2b 83.2 + .2b 82.7 + .2 80.9 + .1WET 73.3 + .2 78.1 + .2c 81.4 + .2c 82.4 + .2c 82.3 + .2 80.8 + .1aSprinkling effect (P < .01)bcMeans within a parameter, position, and time with different superscripts differ (P < .05)dTHI = Temperature-Humidity Index = Temperature - (.55 - (.55 x (Relative humidity/100))) x(Temperature - 58)105104103102101100Temperature, oF800900100011001200130014001500160017001800190020002100220023002400 100200300400500600700Time of day, hourDryWetFigure 3. Effect of altered feeding time on tympanic temperature of steers on days 61 - 62. Feedingtime x time interactino (P<.001). *Value within a time differ (P<.05).

Effect of Altered Feeding and Sprinkling on Performance and Body Temperature of Steers Finished in the Summer

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Effect of Altered Feeding and Sprinkling on Performance and Body Temperature of Steers Finished in the Summer

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