Forage source and quality in finishing cattle programs continue to be a source of concern because of economics and also because of their impact on beef eating qualities. The integration of pasturing systems for cattle finishing programs should allow the producer to produce a leaner and possibly more economical beef supply thus benefiting the consumer and the producer. This experiment was designed to investigate alternative pasture management systems for finishing cattle and to study the impact on meat quality

Hoffman, M. Peter

Williams, Tracy A.

English

Forage source and quality in finishing cattle programs continue to be a source of concern because of economics and also because of their impact on beef eating qualities. The integration of pasturing systems for cattle finishing programs should allow the producer to produce a leaner and possibly more economical beef supply thus benefiting the consumer and the producer. This experiment was designed to investigate alternative pasture management systems for finishing cattle and to study the impact on meat quality.</p

Williams, Tracy

Hoffman, M.

Digital Repository @ Iowa State University (ISU)

The Effect on Meat Quality of Integrating Pasturing Systems into Cattle Finishing Programs

The effect on meat quality of integrating pasturing systems into cattle finishing programs was observed over a two-year period. Year one consisted of 84 fall born calves and 28 spring born calves and year two consisted of 116 fall born calves. The effect of using Rumensinâ for cattle on bromegrass pasture was incorporated into year one. In year two cattle on pasture received bromegrass pasture, and one treatment group received switchgrass during the warm season. In both years there was a control group of calves that went directly to the feedlot with the remaining calves going to pasture for varying periods of time before being finished in drylot. At the conclusion of the feeding trial, cattle were processed into beef, and a ribeye steak was removed from each carcass for sensory evaluation. In year one cattle that were on pasture the longest had the lowest (P\u3c0.05) average quality grades. In year two this trend was reversed, and cattle placed directly into drylot had the lowest (P\u3c0.05) average quality grades. In both years cattle carcasses in all treatments averaged yield grade 2. Warner Bratzler shear force values were not affected by treatments. Sensory panel evaluations indicated tenderness was unaffected by treatments, and in year two flavor and flavor intensity were unaffected by treatments. In year one flavor intensity was lowest (P\u3c0.05) for steaks derived from cattle that were on pasture the longest and received Rumensinâ. Inclusion of Rumensinâ for cattle on pasture did not influence yield and quality grades or affect tenderness, juiciness, and flavor. Results of this study indicate that steer calves placed on cool and warm season pastures prior to being finished in drylot, can produce carcasses with acceptable yield and quality grades and that the meat eating qualities will be largely unaffected by the inclusion of pasture

Hoffman, M. P.

Iowa State University Computer Science Technical Reports

The effect on meat quality of integrating pasturing systems into cattle finishing programs was observed over a two-year period. Year one consisted of 84 fall born calves and 28 spring born calves and year two consisted of 116 fall born calves. The effect of using Rumensinâ for cattle on bromegrass pasture was incorporated into year one. In year two cattle on pasture received bromegrass pasture, and one treatment group received switchgrass during the warm season. In both years there was a control group of calves that went directly to the feedlot with the remaining calves going to pasture for varying periods of time before being finished in drylot. At the conclusion of the feeding trial, cattle were processed into beef, and a ribeye steak was removed from each carcass for sensory evaluation. In year one cattle that were on pasture the longest had the lowest (P<0.05) average quality grades. In year two this trend was reversed, and cattle placed directly into drylot had the lowest (P<0.05) average quality grades. In both years cattle carcasses in all treatments averaged yield grade 2. Warner Bratzler shear force values were not affected by treatments. Sensory panel evaluations indicated tenderness was unaffected by treatments, and in year two flavor and flavor intensity were unaffected by treatments. In year one flavor intensity was lowest (P<0.05) for steaks derived from cattle that were on pasture the longest and received Rumensinâ. Inclusion of Rumensinâ for cattle on pasture did not influence yield and quality grades or affect tenderness, juiciness, and flavor. Results of this study indicate that steer calves placed on cool and warm season pastures prior to being finished in drylot, can produce carcasses with acceptable yield and quality grades and that the meat eating qualities will be largely unaffected by the inclusion of pasture.</p

2001 Beef Research Report — Iowa State University121The Effect on Meat Quality of Integrating Pasturing Systems intoCattle Finishing ProgramsA.S. Leaflet R1762Tracy A. Williams, graduate research assistant, andM. P. Hoffman, professor of animal scienceSummaryThe effect on meat quality of integrating pasturingsystems into cattle finishing programs was observed overa two-year period.  Year one consisted of 84 fall borncalves and 28 spring born calves and year two consistedof 116 fall born calves.  The effect of using Rumensinfor cattle on bromegrass pasture was incorporated intoyear one.  In year two cattle on pasture receivedbromegrass pasture, and one treatment group receivedswitchgrass during the warm season.  In both yearsthere was a control group of calves that went directly tothe feedlot with the remaining calves going to pasturefor varying periods of time before being finished indrylot.  At the conclusion of the feeding trial, cattle wereprocessed into beef, and a ribeye steak was removedfrom each carcass for sensory evaluation.In year one cattle that were on pasture the longest hadthe lowest (P<0.05) average quality grades.  In year twothis trend was reversed, and cattle placed directly intodrylot had the lowest (P<0.05) average quality grades.In both years cattle carcasses in all treatments averagedyield grade 2.  Warner Bratzler shear force values werenot affected by treatments.  Sensory panel evaluationsindicated tenderness was unaffected by treatments, andin year two flavor and flavor intensity were unaffectedby treatments.  In year one flavor intensity was lowest(P<0.05) for steaks derived from cattle that were onpasture the longest and received Rumensin.  Inclusionof Rumensin for cattle on pasture did not influenceyield and quality grades or affect tenderness, juiciness,and flavor.  Results of this study indicate that steercalves placed on cool and warm season pastures prior tobeing finished in drylot, can produce carcasses withacceptable yield and quality grades and that the meateating qualities will be largely unaffected by theinclusion of pasture.IntroductionThe question of forage source and quality in finishingcattle programs continues to be a source of concern in thebeef industry, not only because of economics, but alsobecause of its impact on beef eating qualities.  Cattlefinished on high levels of forage have been characterized inpast studies as having lower dressing percentages, darkerribeye color, limited retail acceptability and lowerpalatability attributes.  Grain-finished cattle have beencharacterized as having improved meat color and retailacceptability, reduced shear force, and higher dressingpercentages.Today consumers demand beef products that are leanand highly palatable.  The use of large quantities of forageto minimize external and seam fat is one production methodto accommodate consumer demands.  The integration ofpasturing systems for cattle finishing programs should allowthe producer to produce a leaner and possibly moreeconomical beef supply thus benefiting the consumer andthe producer.  The problem is that packers have traditionallydiscriminated against forage-fed market cattle due toanticipated meat quality problems of cattle finished onforages.This experiment was designed to investigate alternativepasture management systems for finishing cattle and tostudy the impact on meat quality.  The objectives of thisresearch were to determine the eating qualities of ribeyesteaks from cattle provided pasture during the finishingprogram.Materials and MethodsA 2-year study was conducted involving 84 fall-bornand 28 spring-born calves in year one and 116 fall-borncalves in year two, all of similar genotypes.  Fall-borncalves were started on test in May and spring-born calves inOctober.  Seven treatments were imposed in year 1: 1) fall-born calves direct to feedlot; 2 and 3) fall-born calvesprovided cool season pasture with or without Rumensinand then to the feedlot at the end of July; 4 and 5) fall-borncalves provided cool season pasture with or withoutRumensin and then to the feedlot at the end of October;and 6 and 7) spring-born calves provided cool seasonpasture with or without Rumensin and then to the feedlotat the end of October.  Four treatments with all cattlereceiving Rumensin were imposed for year 2: 1) calvesdirect to feedlot; 2) calves provided cool season pasture andthen to the feedlot at the end of July; 3) calves provided coolseason pasture and then to the feedlot at the end of October;and 4) calves provided cool season pasture until July,followed by warm season grass until the middle of August,cool season pasture until the end of October, and then to thefeedlot.  Rotationally grazed cool season grass consisted ofsmooth bromegrass and warm season grass consisted ofswitchgrass.  The feedlot diet consisted of an 82%concentrate diet containing corn, alfalfa hay, and a protein,vitamin and mineral supplement containing Rumensin and2001 Beef Research Report — Iowa State University122molasses.  When steers averaged 1,150 lb (year 1) and 1,200lb (year 2) they were processed into beef.Following processing, one 12th rib ribeye steak wasremoved from each carcass.  These samples were vacuumpackaged in oxygen impermeable cryovac bags and agedpostmortem for 15 days.  After postmortem aging they weretrimmed of external fat and vacuum packaged and stored ina blast freezer.  These steaks were later used for meatquality determination by sensory panel evaluation andWarner Bratzler shear force values.The sensory panel evaluation consisted of eightpanelists.  Testing was conducted by tasting samples fromeach treatment, and scoring was based on an eight pointscoring system with eight being the best.  The meat qualitycharacteristics evaluated were tenderness, juiciness, flavorintensity, and flavor.  The samples were broiled to a finaltemperature of 71°C.  The steaks were taken to a sensorypanel room and each panelist received two half-inch cubesfrom each steak for evaluation.  These same steaks had six1.5-inch cores removed for Warner Bratzler shearevaluation.There were seven treatment combinations in the firsttrial, with four replications in treatment 1 and tworeplications in each of the remaining six treatments.  In thesecond trial there were four treatments, each with fourreplications.Results and DiscussionThe mean values for hot carcass weight (HCW),backfat (BF), ribeye area (REA), kidney, pelvic and heartfat (KPH), yield grade (YG), and quality grade (QG) arepresented in Table 1.  Fall-born steers on pasture untilOctober and not receiving Rumensin had lower (P<0.05)HCW when compared with the continuous drylot fed steers,all cattle on pasture until July, and spring-born calvesreceiving Rumensin on pasture.  Fall-born cattle onpasture until October had lower (P<0.05) BF than steers thatwent directly to the feedlot.  The KPH followed the trend ofBF with cattle on pasture for the longest duration having theleast amount of KPH (P<0.05).  Quality grades for all fall-born cattle on pasture until October were poorer (P<0.05)than the other treatments.Table 1.  Least square means and SEM of carcass composition and meat eating qualities of steers in year oneTreatmentsFall born calves Spring born calvesDirect Pasture to July 28 Pasture to Oct. 16 Pasture to Oct. 16Variabletodrylot(1)Noionophore(2) Ionophore(3)Noionophore(4)Ionophore(5)Noionophore(6)Ionophore(7)Hot carcasswt., lb.747.1a±13.5 737.2a±19.1 734.0a±19.1 670.0b±19.8 710.0ab±19.1 721.9ab±19.1 733.6a±19.1Backfat, in. 0.6a±0.03 0.5abc±0.1 0.6abc±0.1 0.4bc±0.1 0.4bc±0.1 0.5abc±0.1 0.5abc±0.1Ribeye area,in.213.1±0.2 12.4±0.3 12.7±0.3 12.4±0.3 12.6±0.3 12.9±0.3 12.9±0.3Kidney,pelvic, heartfat, %2.4a±0.1 2.7bc±0.1 2.7bc±0.1 2.2ad±0.1 1.9d±0.1 3.0bc±0.1 2.9bc±0.1Yield gradef 2.7±0.1 2.6±0.2 2.6±0.2 2.4±0.2 2.4±0.2 2.5±0.2 2.6±0.2Quality gradeg 6.1ad±0.2 6.1abde±0.2 6.1abde±0.2 6.7ac±0.3 6.8bc±0.2 5.8d±0.2 5.5de±0.2WarnerBraztler shear,kgfh2.3±0.1 2.4±0.1 2.2±0.1 2.5±0.1 2.7±0.1    2.4±0.1     2.3±0.1Tendernessi 5.7±0.1     5.4±0.2 5.9±0.2 5.8±0.2 5.4±0.2 5.7±0.2 5.6±0.2Juicinessi 5.3bc±0.1     5.1b ±0.2 5.4bc±0.2 5.3bc±0.2 5.2bc±0.2 5.7c±0.2 5.6bc±0.2Flavorintensityi5.2bd±0.1    5.3bcd±0.1 5.4bc±0.1 5.3bc±0.1 5.0d±0.1 5.5bc±0.1 5.5c±0.1Flavori 5.4bc±0.1     5.3bc±0.1 5.5bc±0.1 5.4bc±0.1 5.2c±0.1 5.6b±0.1 5.6b±0.1a,b,c,d,e Means within the same row with different letters are different P<0.05.fYield grades were called by the USDA Meat Grading Service.gQuality grade was converted to a number system: Choice+=4; Choice0=5; Choice-=6; Select+=7; etc.hWarner Bratzler shear measured by kilograms of force (kgf).iSensory panel scores based on eight point scale (8=excellent; 1=very poor).2001 Beef Research Report — Iowa State University123The means for body composition for year two arepresented in Table 2.  There were no significant differencesamong treatments for HCW and REA.  Backfat for cattle onbromegrass pasture until October and cattle that were onwarm season and cool season grass was less (P<0.05) thanfor cattle that went directly to the feedlot and were onbromegrass pasture until July.  Carcasses from cattle thatwere on bromegrass pasture until July had higher (P<0.05)KPH.  The YG for cattle on bromegrass pasture untilOctober was higher (P<0.05) than the YG for cattle onbromegrass and switchgrass pastures.  The QG for the steersthat went directly to the feedlot was lower (P<0.05) than forthe other three treatments.  This may have been due toslightly lower HCW.  The effect of integrating pasture intocattle finishing programs for years one and two in this studygenerally provided similar results for YG and QG.  In bothtrials there were differences (P<0.05) among treatments forQG, and in year 2 differences (P<0.05) existed for YG.However, all YG were within the YG 2 category, and nearlyall QG averaged low Choice or higher.The Warner Bratzler shear force values are presented inTables 1 and 2.  In neither year were there any differencesamong treatments for tenderness.  Thus time on pasture didnot affect tenderness.Table 1 presents the sensory panel evaluations fortenderness, juiciness, flavor intensity and flavor in year one.The sensory panel also found no differences in tendernessamong treatments.  Although differences (P<0.05) wereobserved among treatments for juiciness, flavor intensityand flavor, no consistent patterns were observed.  However,in spite of these unexplainable differences among treatmentsfor juiciness and flavor attributes, all sensory scoresaveraged five or higher and average scores of five or higherare considered acceptable eating attributes.Year two sensory panel evaluations are shown in Table2.  There were no significant differences among treatmentsfor tenderness, flavor intensity and flavor.  There was adifference (P<0.05) in juiciness.  Cattle on bromegrass andswitchgrass pastures had a significantly lower score thansteers on bromegrass pastures until July and October,respectively.Table 2. Least square means and SEM of carcass composition and meat eating quality of steers in year twoTreatmentsDirectto drylotBromegrass pastureto July 13Bromegrass pasturetoOct. 1Bromegrass andswitchgrass pasture toOct 1Variable (1) (2) (3) (4) SEMHot carcasswt., lb.730.6 764.1 744.6 754.4 12.5Backfat, in. 0.5a 0.5a 0.4b 0.4b 0.02Ribeye area,in.213.2 13.1 13.1 13.4 0.2Kidney,pelvic, heartfat, %2.3a 2.7b 2.3a 2.4a 0.1Yield graded 2.5ab 2.6ab 2.7b 2.4a 0.1Quality gradee 6.4a 5.8b 5.8b 5.8b         0.2WarnerBratzlershear, kgff2.5 2.5 2.4 2.4 0.1Tendernessg 5.3 5.6 5.5 5.3 0.1Juicinessg 5.0ac 5.5b 5.2c 4.8a 0.1Flavorintensityg5.2 5.7 5.4 5.2 0.3Flavorg 5.4 5.4 5.5 5.3 0.1a,b,cMeans within the same row with different letters are different P<0.05.dYield grades were called by the USDA Meat Grading Service.eQuality grade was converted to a number system: Choice+=4; Choice0=5; Choice-=6; Select+=7; etc.fWarner Bratzler shear measured by kilograms of force (kgf).gSensory panel scores based on eight point scale (8=excellent; 1=very poor).2001 Beef Research Report — Iowa State University124ImplicationsThe integration of cool and warm season grasspasturing systems into cattle finishing programsdoes not seem to have a major impact on cattlecarcass yield grades and resulting meat eatingquality attributes such as tenderness, juiciness andflavor.  Although carcass quality grades showedsome differences due to treatments in this study, itseems this is primarily related to hot carcass weightand might thus be corrected with propermonitoring of live slaughter weight.AcknowledgmentsThe assistance of the Western Iowa Research Farmstaff; Iowa State University Meat Laboratory; Julie Roberts,secretary; F.C. Parrish, Jr., university professor;. Phillip M.Dixon, associate professor; and. James R. Russell, professorof animal science, is appreciated.

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The Effect on Meat Quality of Integrating Pasturing Systems into Cattle Finishing Programs

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