Hartnell Y. Hyun, GE Bressner, M. Ellis, AJ Lewis, R. Fischer, EP Stanisiewski and GF

12 Pages·2004·0.25 MB·English

Performance of growing-finishing pigs fed diets containing Roundup Ready corn
(event nk603), a nontransgenic genetically similar corn, or conventional corn lines
Y. Hyun, G. E. Bressner, M. Ellis, A. J. Lewis, R. Fischer, E. P. Stanisiewski and G. F.
Hartnell
J ANIM SCI 2004, 82:571-580.
The online version of this article, along with updated information and services, is located on
the World Wide Web at:
http://www.journalofanimalscience.org/content/82/2/571
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Performance of growing-finishing pigs fed diets containing Roundup Ready
corn (event nk603), a nontransgenic genetically similar corn,
or conventional corn lines
Y. Hyun*, G. E. Bressner*, M. Ellis*1, A. J. Lewis†, R. Fischer†,
E. P. Stanisiewski‡, and G. F. Hartnell†
*Department of Animal Sciences, University of Illinois, Urbana 61801; †Department of Animal Science,
University of Nebraska, Lincoln 68583; and ‡Monsanto Company, St. Louis, MO 63167
ABSTRACT: Twostudieswereconductedattwoloca- in Study 2. The test corns were included at a fixed
tionstoevaluategrowthperformanceandcarcasschar- proportion of the diet in both studies. Animals had ad
acteristicsofgrowing-finishingpigsfeddietscontaining libitumaccesstofeedandwater.Pigswereslaughtered
either glyphosate-tolerant Roundup Ready (event usingstandard proceduresand carcassmeasurements
nk603)corn,anontransgenicgeneticallysimilarcontrol weretaken.InStudy1,overallADG,ADFI(as-fedba-
corn (RX670), or two conventional sources of non- sis),andgain:feed(G:F)werenotaffected(P>0.05)by
transgenic corn (RX740 and DK647). A randomized corn line. In Study 2, there was no effect of corn line
completeblockdesign(threeandfourblocksinStudies onoverallADFI(as-fedbasis)orG:Fratio.Inaddition,
1and2,respectively)witha2×4factorialarrangement overall ADG of barrows fed the four corn lines did not
of treatments (two genders and four corn lines) was differ(P>0.05);however,overallADGofgiltsfedcorn
used. Study 1used 72 barrows and 72gilts (housed in DK647wasgreater(P<0.05)thanthatofpigsfedthe
single-gender groups of six; six pens per dietary treat- other corn lines. There was no effect (P > 0.05) of corn
ment) with initial and final BW of approximately 22 lineoncarcassyieldorfatnessmeasurementsineither
and116kg,respectively.Study2used80barrowsand study.Differencesbetweenbarrowsandgiltsforgrowth
80 gilts (housed in single-gender groups of five; eight andcarcasstraitsweregenerallysimilarforbothstud-
pens per dietary treatment) with initial and final BW ies and in line with previous research. Overall, these
ofapproximately30and120kg,respectively.Pigswere resultsindicatethatRoundupReadycorn(nk603)gives
housed in a modified open-front building in Study 1 equivalentanimalperformancetoconventionalcornfor
andinanenvironmentallycontrolledfinishingbuilding growing pigs.
Key Words: Carcass, Growth, Pigs, Transgenic Corn
2004 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2004. 82:571–580
Introduction singleprotein,themodified maizeenzyme5-enolpyru-
vylshikimate-3-phosphate synthase (mEPSPS). Sub-
Genetically enhanced crops offer producers a wide sequently, a second-generation Roundup Ready corn
variety of agronomic benefits. For example, the use of (containingeventnk603)hasbeendeveloped.Thiscorn
herbicide-tolerant corn, such as Roundup Ready, pro- expresses CP4 EPSPS protein, which is derived from
vides the crop producer with flexible and broad-spec- Agrobacteriumsp.(StrainCP4).BothEPSPSandCP4
trum postemergent weed control options. Glyphosate, EPSPS proteins are functionally similar to wild-type
whichistheactiveingredientintheherbicideRoundup, plantEPSPSenzymesexceptforamuch-reducedaffin-
isoneofthemostwidelyusedherbicides(Sidhuetal., ity for glyphosate (LeBrun et al., 1997). Previous re-
2000). Roundup Ready corn (event GA21) was devel- search has demonstrated Roundup Ready corn to be
oped to be tolerant to glyphosate by the insertion of a substantiallyequivalentinnutrientcompositiontothe
geneticallyrelatednontransgeniccorn(Stanisiewskiet
al., 2001; Taylor et al., 2001).
Because finishing pigs consume large quantities of
1Correspondence:216AnimalSciencesLaboratory,1207W.Greg- corn,researchwasconductedtodeterminewhetherpigs
ory Dr. (phone: [phone]; fax: [phone]; e-mail: mellis7@
fed diets containing a Roundup Ready corn (event
uiuc.edu).
nk603) and conventional (nontransgenic) corn have
ReceivedFebruary19,2003.
AcceptedSeptember24,2003. similar performance. Therefore, the objective of this
571
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572 Hyunetal.
researchwastocomparegrowthperformanceandcar- pigs,withafloorspaceof1.2m2/pig.Study2wascarried
cass quality of growing-finishing pigs fed diets con- outinanenvironmentallycontrolledfinishingbuilding
taining either Roundup Ready corn with event nk603, with part-solid, part-slatted floors and used a total of
a nontransgenic genetically similar control corn 32 single-gender pens (barrows or gilts) with five pigs
(RX670), or two conventional nontransgenic hybrids per pen, giving eight pens per dietary treatment. Pen
(RX740 and DK647). dimensions(length×width)were2.6×1.8m,givinga
floorspaceof0.94m2/pig.Thetemperaturewithinthe
Materials and Methods building was controlled by mechanical ventilation
linked to a thermostat set at 24°C during the early
This research consisted of two experiments, with stagesofthestudyandreducedto21°Cwhenthepigs
Study1beingcarriedoutattheUniversityofNebraska reached an average of 50 kg BW. Temperature and
(Lincoln)andStudy2attheUniversityofIllinois(Ur- humiditylevelsinthebuildingwererecordedonadaily
bana). Similar experimental designs and approaches basis using Hobo H8 Loggers (Onset Computer Corp.,
were used at both locations. Experimental protocols Bourne, MA). The average temperature during the
were approved by the respective institutional animal study was 22.2 ± 2.53°C and the average relative hu-
careandusecommitteesbeforethestartofthestudies. midity was 52.2 ± 12.46%.
Pigshadadlibitumaccesstofeedandwaterthrough-
Animals and Treatments out the experimental period, which ended after 103 d
inStudy1andwhentheaverageBWofallthepensof
InStudy1,144crossbred(Danbred×[Danbred×NE pigs within a block reached approximately 120 kg in
White line]) pigs (equal numbers of barrows and gilts) Study 2, at which time all pigs in the block were re-
with an initial BWof 22.6 ± 0.25 kg wereused, and in moved from the experiment.
Study 2, 160 PIC (337 sires × C22 dams) pigs (equal
numbers of barrows and gilts) with an initial BW of Data and Sample Collection
29.9 ± 0.54 kg were used.
Arandomizedcompleteblock design(threeandfour In both studies, pigsand feeders were weighed and
blocks in Studies 1 and 2, respectively) with a 2 × 4 feed intake measured every 2 wk throughout the
factorial arrangement of treatments was used. Blocks study, and the amount of feed added to each feeder
were based on initial weight and pen location within was recorded to determine ADG, ADFI (as-fed basis),
the building. There were two genders (barrows and and gain:feed (G:F).At the end ofthe experiment, all
gilts) and four genetic corn lines (a transgenic hybrid pigswereultrasonicallyscannedusinganAlokaModel
containingeventnk603,thenontransgeniccontrolcorn 500 B-mode ultrasound scanner fitted with a VST-
[RX670], and two conventional hybrids [RX740; As- 5021-3 probe (Corometrics Medical Systems, Wall-
grow, Des Moines, IA, and DK647; Dekalb Seeds, De- ingford,CT).Atransversescanimagewastakenover
Kalb,IA]).Dietscontainedcornandsoybeanmealand the 10th rib, and backfat depth (over the middle of
were fortified with vitamins and minerals to meet or thelongissimusmuscle)andlongissimusmusclearea
exceedtheNRC(1998)requirementsfortheweightsof were measured on the scans.
pigsused.Thecompositionofthecornsispresentedin Attheendoftheexperiment,thepigsfromthetwo
Table 1. In Study 1 (Tables 2 and 3), there were four studies were shipped to different abattoirs and har-
dietary phases (Grower I, 22.6 to 42.9 kg BW; Grower vestedusingstandardprocedures.InStudy1,carcass
II, 42.9 to 69.7 kg BW;Finisher I, 69.7 to 97.9 kg BW; characteristicsweremeasuredusingtotalbodyelectri-
Finisher II, 97.9 to 116.4 kg BW), and the inclusion calconductivity(TOBEC;ModelRIPS4;MeatQuality,
rateofthecornwasfixedwithineachphase(68.1,74.2, Inc.,Springfield,IL;Forrestetal.,1989).Carcassmea-
78.1, and 81.8% for Grower I, Grower II, Finisher I, surementsweretaken at24hpostmortem inStudy1
andFinisher II,respectively). Study1 wascarried out andincludedmidlinefatdepths(oppositethefirstrib,
for a fixed time period of 103 d, with each diet phase 10th rib, last rib, and last lumbar vertebra), and lon-
lasting28d,exceptFinisherII,whichwas19d.Study gissimusmusclearea atthe10thrib.In Study2,car-
2 (Table 4) was carried out over a fixed weight range, cass measurements were taken at 10 h postmortem
and there were three dietary phases (Grower [29.9 to and included carcass length (measured from the cra-
50.1kgBW],FinisherI[50.1to78.7kgBW],Finisher nialtipoftheaitchbonetothecranialedgeofthefirst
II[78.7to119.4kgBW]),andtheinclusionrateofthe ribadjacenttothefirstthoracicvertebra),midlinefat
cornlineswasfixedwithineachphase(70,74,and77% depths(oppositethefirstrib,lastrib,andlastlumbar
for Grower, Finisher I, and Finisher II, respectively). vertebra), 10th-rib fat depth (measured over the lon-
Dietswerechangedbetweenphaseswhentheaverage gissimusmuscleatthree-quartersofthedistancefrom
weight of all pigs in a block reached the designated the midline), and longissimus muscle depth and area
weight of 50 and 80 kg, respectively. at the 10th rib.
InStudyl,thepigswerehousedinamodified-open- Musclequalitymeasurementstakenonthecutsur-
front building with 24 pens (pen dimensions [length × faceofthelongissimusmuscleatthe10thribincluded
width]were4.8m×1.5m),andeachpencontainedsix pH, firmness and marbling scores (NPPC, 1991), and
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Transgeniccornfeedingtoswine 573
Table 1. Nutrient composition of the corn lines (as-fed basis)
Cornlinea
Item,% nk603 RX670 DK647 RX740
Drymatter 87.8 88.3 85.4 86.5
Crudeprotein 7.35 7.90 7.85 8.13
Crudefat 3.75 3.77 3.43 4.13
ADF 2.9 3.0 3.5 3.8
NDF 9.1 9.6 10.3 9.5
Crudefiber 2.6 2.1 2.7 1.9
Crudeash 7.35 7.35 7.35 7.35
Aminoacidcomposition:
Arginine 0.29 0.29 0.36 0.26
Histidine 0.21 0.21 0.23 0.22
Isoleucine 0.22 0.23 0.24 0.26
Leucine 0.84 0.93 0.93 1.04
Lysine 0.23 0.25 0.25 0.24
Methionine 0.19 0.17 0.18 0.18
Cysteine 0.18 0.20 0.24 0.24
Phenylalanine 0.36 0.37 0.38 0.40
Tyrosine 0.27 0.23 0.25 0.25
Threonine 0.29 0.30 0.30 0.30
Tryptophan 0.05 0.06 0.06 0.06
Valine 0.31 0.32 0.34 0.35
ank603 = transgenic Roundup Ready corn; RX670 = nontransgenic control corn; RX740 and DK647 =
conventionalcornhybrids.
Minolta L* (lightness), a* (red-green scale), and b* Inbothstudies,thechemicalcompositionofthelon-
(yellow-blue scale) values in Study l and color and gissimus muscle was determined on a subsample of
firmness and marbling scores in Study 2 (NPPC, threepigs randomlyselectedfromwithin eachpen.A
1991, 2000). longissimus muscle sample was taken at the 10th rib
Table 2. Composition of Grower I and Grower II diets—Study 1 (as-fed basis)
Cornlineindieta
nk603 RX670 DK647 RX740
Ingredient,% GrowerI GrowerII GrowerI GrowerII GrowerI GrowerII GrowerI GrowerII
Corn 68.07 74.21 68.07 74.21 68.07 74.21 68.07 74.21
Soybeanmeal(dehulled) 26.00 20.25 26.00 20.25 26.00 20.25 26.00 20.25
Tallow 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00
Dicalciumphosphate 1.25 0.85 1.25 0.85 1.25 0.85 1.25 0.85
Limestone 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40
Salt 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
Vitaminpremixb 0.70 0.70 0.70 0.70 0.70 0.70 0.70 0.70
Tracemineralpremixc 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10
Tyland 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13
L-Lysine(cid:1)HCl 0.05 0.06 0.05 0.06 0.05 0.06 0.05 0.06
Chemicalcomposition,%e
ME,kcal/kgf 3,464 3,480 3,464 3,480 3,464 3,480 3,464 3,480
Crudeprotein 17.79 15.63 18.16 16.04 18.35 16.00 18.32 16.04
Calcium 0.70 0.60 0.70 0.60 0.70 0.60 0.70 0.60
Phosphorus 0.60 0.50 0.60 0.50 0.60 0.50 0.60 0.50
Lysine 0.95 0.80 0.96 0.82 0.96 0.82 0.96 0.82
ank603=transgenicRoundupReadycorn;RX670=nontransgeniccontrolcorn;RX740andDK647=conventionalcornhybrids.
bThevitaminpremixsuppliedperkilogramofdiet:vitaminA(asretinylacetate),3,088IU;vitaminD (ascholecalciferol),386IU;vitamin
3
E(asα-tocopherolacetate),15IU;vitaminK(asmenadionesodiumbisulfite),2.3mg;riboflavin,3.9mg;D-pantothenicacid,15.4mg;niacin,
23.3mg;choline,77.2mg;vitaminB ,15.4(cid:1)g.
12
cThetracemineralpremixsuppliedperkilogramofdiet:Zn(asZnO),110mg;Fe(asFeSO (cid:1)H O),110mg;Mn(asMnO),22mg;Cu(as
4 2
CuSO (cid:1)H O)11mg;I(asCa(IO )(cid:1)H O),0.22mg;Se(asNa SeO ),0.3mg.
4 2 3 2 2 3
dTylan-40(ElancoAnimalHealth,Indianapolis,IN);tosupply110g/kgtylosininthefinalfeed.
eCalculatedvaluesbasedonanalyzedvaluesforthecornandsoybeanmealsamplesused.
fBasedonvaluesfromNRC(1998).
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574 Hyunetal.
Table 3. Composition of Finisher I and Finisher II diets—Study l (as-fed basis)
Cornlineindieta
nk603 RX670 DK647 RX740
Ingredient,% FinisherI FinisherII FinisherI FinisherII FinisherI FinisherII FinisherI FinisherII
Corn 78.11 81.79 78.11 81.79 78.11 81.79 78.11 81.79
Soybeanmeal(dehulled) 16.25 12.75 16.25 12.75 16.25 12.75 16.25 12.75
Tallow 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00
Dicalciumphosphate 0.93 0.75 0.93 0.75 0.93 0.75 0.93 0.75
Limestone 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40
Salt 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
Vitaminpremixb 0.70 0.70 0.70 0.70 0.70 0.70 0.70 0.70
Trace-mineralpremixc 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10
Tyland 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13
L-Lysine(cid:1)HCl 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08
Chemicalcomposition,%e
ME,kcal/kgf 3,479 3,487 3,479 3,487 3,479 3.487 3,479 3,487
Crudeprotein 13.53 12.41 13.96 12.46 13.92 12.42 14.14 12.65
Calcium 0.60 0.55 0.60 0.55 0.60 0.55 0.60 0.55
Phosphorus 0.50 0.45 0.50 0.45 0.50 0.45 0.50 0.45
Lysine 0.69 0.60 0.71 0.62 0.71 0.62 0.71 0.62
ank603=transgenicRoundupReadycorn;RX670=nontransgeniccontrolcorn;RX740andDK647=conventionalcornhybrids.
bThevitaminpremixsuppliedperkilogramofdiet:vitaminA(asretinylacetate),3,088IU;vitaminD (ascholecalciferol),386IU;vitamin
3
E(asα-tocopherolacetate),15IU;vitaminK(asmenadionesodiumbisulfite),2.3mg;riboflavin,3.9mg;D-pantothenicacid,15.4mg;niacin,
23.3mg;choline,77.2mg;vitaminB ,15.4(cid:1)g.
12
cThetracemineralpremixsuppliedperkilogramofdiet:Zn(asZnO),110mg;Fe(asFeSO (cid:1)H O),110mg;Mn(asMnO),22mg;Cu(as
4 2
CuSO (cid:1)H O)11mg;I(asCa(IO )(cid:1)H O),0.22mg;Se(asNa SeO ),0.3mg.
4 2 3 2 2 3
dTylan-40(ElancoAnimalHealth,Indianapolis,IN);tosupply110g/kgtylosininthefinalfeed.
eCalculatedvaluesbasedonanalyzedvaluesforthecornandsoybeanmealsamplesused.
fBasedonvaluesfromNRC(1998).
from 18 pigs per treatment (nine barrows and nine RX670, RX740, and DK647), block, and gender × corn
gilts)inStudy1and24pigspertreatment(12barrows line interaction. Least squares means were evaluated
and 12 gilts) in Study 2. Longissimus samples were using the PDIFF and STDERR options of SAS.
homogenized and analyzed for protein, fat, and mois-
ture using the procedures of Novakofski et al. (1989). Results and Discussion
Corn samples from each line were collected before
thestartoftheexperimentfornutrientanalysis(Table Growth Performance
1). Also, a soybean meal sample was collected at the
In Study 1, ADG, ADFI, and G:F were not affected
feed mill during the production of each dietary phase
(P > 0.05) by corn line (Table 5). In Study 2 (Table 6),
for the determination of crude protein and amino
there was a corn line × gender interaction for ADG in
acid concentrations.
thegrowingphase(P<0.05)andintheoverallgrowth
period (P < 0.05) as well as for G:F in the Finisher I
Sample Analysis
phase (P< 0.01).For barrows,there wasno effect (P>
Cornandsoybeanmealsamplesweregroundthrough 0.05) of corn line on ADG during any phase; however,
a1-mmscreenbeforeanalysis.Ingredientsampleswere gilts fed DK647 grew faster (P < 0.05) than those fed
analyzed in duplicate for crude protein according to theotherlinesfortheoverallgrowthperiodandfaster
AOAC(1995)procedures.Sampleswerehydrolyzedfor thanthosefeddietswithnk603andRX740inthegrow-
20husing6NHClat107°Cbeforeseparationofamino ingperiod(Table6).DuringFinisherI,barrowsfeddiet
acidsbyion-exchangeHPLC.Afterelution,aminoacids nk603 had a higher G:F than those fed RX670 and
were quantified fluorometrically using o-phthalalde- DK647, whereas gilts fed hybrid DK647 had a higher
hyde as a derivatization reagent (AOAC, 1995). G:F than those fed RX670 (Table 6). However, there
wasnoeffect(P>0.05)ofcornlineonG:Ffortheoverall
Statistical Analysis growth period (Table 6).
Different approaches to diet formulation were used
Pen was the experimental unit in both studies. All in these two studies. In Study 1, the inclusion rate of
data(growth,carcass,meatquality,andchemicalcom- allingredientswasthesameforalldietswithinaphase.
position)wereanalyzedasarandomizedcompleteblock Thisapproachhasthepotentialdisadvantagethatthe
design using PROC MIXED procedures of SAS (SAS variationinnutrientcompositionofthetestdietscould
Institute, Inc., Cary, NC). The effects included in the produce differences in animal performance indepen-
modelweregender(barrowsandgilts),cornline(nk603, dent of any effect of corn line per se. However, differ-
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Transgeniccornfeedingtoswine 575
I K s
I 0070535092050 0707 a
r 0932670100031 6456 n (
Finishe 77.13.4.2.0.0.0.0.0.0.0.0.0. 3,39413.0.0.0. vitami 1mg;I
U; 1
I O)
RX740 FinisherI 74.0018.003.522.340.770.750.060.050.050.010.050.350.10 3,38215.030.520.540.78 cetate),15 (cid:1)CuSOH42
a s
Grower 65.0027.503.062.100.850.850.040.020.020.010.050.350.15 3,36918.530.610.581.02 ocopherol mg;Cu(a
α-t 22
II 0024260281050 6787 (as O),
Finisher 77.017.20.73.00.70.60.00.10.00.00.00.30.1 3,39513.50.40.40.6 taminE(cid:1)15.4g.n(asMn
vi,2M
Table4.Compositionofthediets—Study2(as-fedbasis) aCornlineindiet nk603RK670DK647 Ingredient,%GrowerFinisherIFinisherIIGrowerFinisherIFinisherIIGrowerFinisherI Corn65.0074.0077.0065.0074.0077.0065.0074.00Soybeanmeal(dehulled)28.8019.2015.3027.4317.8013.5030.1921.10Wheatmiddlings2.433.123.843.984.695.780.000.05Soybeanoil1.441.581.801.261.381.632.482.75Dicalciumphosphate0.920.780.680.850.730.630.920.82Limestone0.800.730.680.850.780.740.800.71(cid:1)-LysineHCl0.010.040.030.040.060.060.000.00L-Methionine0.030.060.110.020.050.090.050.08DLThreonine0.020.040.090.020.050.100.010.04Tryptophan0.000.000.020.000.010.020.000.00bTylan0.050.050.000.050.050.000.050.05cTrace-mineralpremix0.350.350.350.350.350.350.350.35dVitaminpremix0.150.100.100.150.100.100.150.10eChemicalcomposition,%fME,kcal/kg3,3703,3833,3953,3703,3833,3953,3703,383Crudeprotein18.5314.9513.5818.4614.9213.4318.4814.97Calcium0.610.520.470.610.520.470.610.52Phosphorus0.580.530.500.610.550.530.570.51Lysine1.020.780.671.020.780.671.020.78 ank603=transgenicRoundupReadycorn;RX670=nontransgeniccontrolcorn;RX740andDK647=conventionalcornhybrids.bTylan-40(ElancoAnimalHealth,Indianapolis,IN);tosupply44g/kgtylosininthefinalfeed.cThevitaminpremixsuppliedperkilogramofdiet:vitaminA(asretinylacetate),3,088IU;vitaminD(ascholecalciferol),386IU;3(asmenadionesodiumbisulfite),2.3mg;riboflavin,3.9mg;-pantothenicacid,15.4mg;niacin,23.3mg;choline,77.2mg;vitaminBD1(cid:1)dThetracemineralpremixcontained84%saltandsuppliedperkilogramofdiet:Zn(asZnO),110mg;Fe(asFeSOHO),110mg;42(cid:1)Ca(IO)HO),0.22mg;Se(asNaSeO),0.3mg.3223eCalculatedvaluesbasedonanalyzedvaluesforthecornandsoybeanmealsamplesused.fBasedonvaluesfromNRC(1998).
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576 Hyunetal.
Table 5. Least squares means for effects of corn line and gender on growth performance—Study l
Cornlineindieta Gender
Item nk603 RX670 DK647 RX740 SEM Barrow Gilt SEM
Numberofpens 6 6 6 6 — 12 12 —
Initialweight,kg 22.5 22.6 22.6 22.6 0.03 22.8 22.4 0.02
Finalweight,kg 116.4 116.5 116.7 116.2 1.48 121.1b 111.7c 1.05
GrowerI(28dfrom22.6to42.9kg)
Averagedailygain,g 724 716 748 715 13.3 750b 710c 9.4
Averagedailyfeedintake,kgd 1.45 1.42 1.47 1.42 0.023 1.48 1.40 0.016
Gain:feed 0.50 0.50 0.51 0.50 0.004 0.50 0.50 0.003
GrowerII(28dfrom42.9to69.7kg)
Averagedailygain,g 945 956 956 957 13.9 1025b 882c 9.9
Averagedailyfeedintake,kgd 2.27 2.31 2.26 2.28 0.042 2.46b 2.11c 0.030
Gain:feed 0.42 0.41 0.42 0.42 0.003 0.42 0.42 0.002
FinisherI(28dfrom69.7to97.9kg)
Averagedailygain,g 1,019 984 1,022 1,016 21.1 1,061b 956c 14.9
Averagedailyfeedintake,kgd 2.90 2.92 2.84 2.86 0.066 3.11b 2.65c 0.047
Gain:feed 0.35 0.35 0.35 0.36 0.004 0.34c 0.36b 0.003
FinisherII(19dfrom97.9to116.4kg)
Averagedailygain,g 983 973 976 967 23.9 1,010b 940c 16.9
Averagedailyfeedintake,kgd 3.19 3.09 3.11 3.06 0.067 3.32b 2.91c 0.047
Gain:feed 0.31 0.32 0.31 0.32 0.005 0.30c 0.32b 0.003
Overall(103dfrom22.6to116.4kg)
Averagedailygain,g 912 912 910 909 13.9 956b 866c 9.8
Averagedailyfeedintake,kgd 2.39 2.38 2.36 2.35 0.043 2.53b 2.21c 0.030
Gain:feed 0.38 0.38 0.39 0.39 0.003 0.38c 0.39b 0.002
ank603=transgenicRoundupReadycorn;RX670=nontransgeniccontrolcorn;RX740andDK647=conventionalcornhybrids.
b,cWithinatreatmentandrow,meanswithoutacommonsuperscriptletterdiffer(P<0.05).
dAs-fedbasis.
Table 6. Least squares means for effects of corn line and gender on growth performance—Study 2
Cornlineindieta Gender
Item nk603 RX670 DK647 RX740 SEM Barrow Gilt SEM
Numberofpens 8 8 8 8 — 16 16 —
Initialweight,kg 30.0 30.2 29.8 29.7 0.26 30.1 29.8 0.18
Finalweight,kg 119.4 118.4 121.8 118.0 1.31 123.1d 115.7e 0.92
Grower(29.9to50.1kg)
Averagedailygain,gb
Barrow 818d 789def 801de 821d 30.2 — — —
Gilt 710f 772def 850d 717ef — — — —
Averagedailyfeedintake,kgh 1.64 1.71 1.77 1.68 0.052 1.74 1.66 0.037
Gain:feed 0.47 0.46 0.47 0.46 0.011 0.47 0.46 0.008
FinisherI(50.1to78.7kg)
Averagedailygain,g 968 996 1,053 1,007 27.0 1,061d 950e 19.1
Averagedailyfeedintake,kgh 2.37 2.59 2.59 2.51 0.064 2.68d 2.35e 0.046
Gain:feedb
Barrow 0.42de 0.38g 0.39fg 0.40efg 0.008 — — —
Gilt 0.40defg 0.39fg 0.42d 0.41def — — — —
FinisherII(78.7to119.4kg)
Averagedailygain,g 1,069 1,011 1,042 1,017 25.5 1,071d 999e 18.0
Averagedailyfeedintake,kgh 3.05 3.01 3.00 2.94 0.064 3.18d 2.81e 0.045
Gain:feed 0.35 0.34 0.35 0.35 0.006 0.34e 0.36d 0.004
Overall(29.9to119.4kg)
Averagedailygain,gc
Barrow 1017d 981d 975d 1009d 20.3 — — —
Gilt 892e 904e 996d 881e — — — —
Averagedailyfeedintake,kgh 2.46 2.52 2.54 2.46 0.042 2.63d 2.35e 0.030
Gain:feed 0.39 0.37 0.39 0.38 0.004 0.38e 0.39d 0.003
ank603=transgenicRoundupReadycorn;RX670=nontransgeniccontrolcorn;RX740andDK647=conventionalcornhybrids.
bCornline×genderinteraction(P<0.05).
cCornline×genderinteraction(P<0.01).
d,e,f,gWithinatreatmentandaninteraction,meanswithoutacommonsuperscriptletterdiffer(P<0.05).
hAs-fedbasis.
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Transgeniccornfeedingtoswine 577
Table 7. Least squares means for the effects of corn line and gender on ultrasound and
carcass measurement—Study 1
Cornlineindieta Gender
Item nk603 DK647 RX670 RX740 SEM Barrow Gilt SEM
Numberofpens 6 6 6 6 — 12 12 —
Ultrasoundmeasurements
Backfatthickness,cm 2.10 2.05 2.07 2.07 0.008 2.31e 1.84f 0.057
Longissimusmusclearea,cm2 48.4 47.9 48.9 46.8 0.88 48.1 47.9 0.62
Backfatthickness,cm
1strib 4.74 4.75 4.81 4.76 0.153 4.94e 4.59f 0.108
10thrib 3.08 2.98 2.97 3.00 0.075 3.27e 2.74f 0.053
Lastrib 3.50 3.38 3.43 3.61 0.103 3.65e 3.31f 0.073
Lastlumbar 2.36 2.31 2.27 2.31 0.076 2.53e 2.10f 0.054
Longissimusmusclearea,cm2 56.6 58.6 56.6 55.3 2.02 55.2 58.3 1.43
TOBECmeasurements
Hotcarcassweight,kg 88.8 89.0 88.7 88.4 1.27 92.1e 85.3f 0.898
Hamweight,kg 10.7 10.3 10.1 10.2 0.12 10.2 10.2 0.09
Loinweight,kg 12.0 12.1 11.9 11.7 0.15 12.0 11.8 0.10
Shoulderweight,kg 12.3 12.4 12.3 12.2 0.17 12.5 12.2 0.12
Primal,%b 38.9 39.0 38.9 38.7 0.37 37.8f 40.0e 0.26
Totalfat-freelean,kgc 42.1 42.4 42.2 42.6 0.60 45.1 44.0 0.42
Percentageoffat-freeleanc 47.6 47.5 47.7 48.2 0.50 49.0f 51.5e 0.42
Leangain,g/dd 338 341 339 343 5.5 345 336 3.9
ank603 = transgenic Roundup Ready corn; RX670 = nontransgenic control corn; RX740 and DK647 =
conventionalcornhybrids.
bCalculatedasthetotalweightoftheprimals(ham,loin,andshoulder)dividedbythehotcarcassweight.
cEstimatedfromtotalbodyelectricalconductivity(TOBEC)scans.
dLeangain=(finalfat-freelean−initialfat-freelean)/103d;initialfat-freelean0.95×[−3.95+(0.418×
liveweight,kg)].
e,fWithinatreatmentandrow,meanswithoutacommonsuperscriptdiffer(P<0.05).
encesinnutrientcompositionamongthetestdietswere performanceof animalson oneof theconventional hy-
small (Tables 2 and 3). In Study 2, the corn inclusion brids rather than being due to any negative effect of
level was fixed within a phase. Diets were formulated the Roundup Ready corn on growth. Diets based on
to thesame nutrientcomposition resultingin variable DK647hadthelowestinclusionofwheatmiddlingsand
inclusionratesacrossthecornlinedietsforotheringre- the highest inclusion of soybean oil (Table 4), and this
dients, particularly soybean meal, wheat middlings, potentially could have contributed to the observed dif-
andsoybeanoil.Thisapproachhasthepotentialdisad- ferenceinoverallgrowthrateamongcornlinesingilts.
vantage that variation in ingredient inclusion rate However, it is unlikely that the inclusion rate differ-
could affect growth. However, differences among the
encesinthisstudy,whichwererelativelysmall,would
dietsforthefourcornlinesiningredientinclusionrates
have affected the relative growth of pigs on the four
were relatively small (Table 4) and were unlikely to
test corn treatments.
have affected animal performance.
Therearelimiteddatainthescientificliteraturecom-
Thus,resultsforbothgendersinStudylandbarrows
paring transgenic with nontransgenic conventional
in Study 2 suggest that the Roundup Ready corn gave
corn fed to pigs. However, research carried out with
equivalent growth performance to the nontransgenic
poultryhasshownresultssimilartothepresentstudy,
control corn (RX670) and the conventional hybrids
withnodifferencesingrowthrate,feedconversioneffi-
tested. For the gilts in Study 2, during the overall
ciency, or fat pad weight among broilers fed Roundup
growth period one of the commercial corns (DK647)
elicitedgreater(P>0.05)growthratesbutsimilarfeed Ready corn (event GA21 or nk603), the nontransgenic
controlcorn,orconventionalcornhybrids(Sidhuetal.,
efficiencies than the other three hybrids. The growth
2000; Taylor et al., 2001).
rate of gilts fed DK647 was similar to that of barrows
Inbothstudies,barrowshadhigher(P<0.05)overall
on the same treatment, a finding that is contrary to
most studies that have compared castrates and gilts ADFIandADGthangilts(Tables5and6).Inaddition,
(Cromwelletal.,1993;Hahnetal.,1995;Stanisiewski gilts had higher (P < 0.01) G:F ratio than barrows in
et al., 2001). In addition, for the overall growth period Finishers I and II and overall (Tables 5 and 6). These
giltsinStudy2fednk603cornhadperformancesimilar results are similar to those of most previous research
to those fed the other two lines tested (RX670 and thathasevaluatedthegrowthperformanceofcastrates
RX740). Thus, the difference in growth rate between andgilts(Labroueetal.,1994;HahnandBaker,1995;
thecornlinesforgiltswasmoreafunctionofthebetter Hyun and Ellis, 2001).
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578 Hyunetal.
Table 8. Least squares means for the effects of corn line and gender on ultrasound and carcass measurements, and
longissimus muscle quality and composition—Study 2
Cornlineindieta Gender
Item nk603 RX670 DK647 RX740 SEM Barrow Gilt SEM
Numberofpens 8 8 8 8 — 16 16 —
Ultrasoundmeasurements
Backfatthickness,cm 1.50 1.47 1.50 1.48 0.034 1.63d 1.34e 0.024
Longissimusmusclearea,cm2b
Barrow 45.9e 44.1efg 42.8fgh 44.5ef 0.92 — — —
Gilt 40.3hi 41.5ghi 43.3efg 39.9i — — — —
Carcassmeasurements
Coldcarcassweight,kgb
Barrow 89.9e 86.8e 87.4e 89.7e 1.78 — — —
Gilt 80.4f 81.4f 88.6e 80.1f — — — —
Dressingpercent 71.3 71.0 72.2 71.9 0.68 71.8 71.4 0.48
Carcasslength,cm 84.8 84.1 85.0 84.1 0.39 84.7 84.4 0.28
Backfatthickness,cm
1strib 4.08 4.08 4.15 3.95 0.109 4.21d 3.91e 0.077
Lastrib 2.25 2.30 2.28 2.25 0.091 2.44d 2.09e 0.064
Lastlumbarvertebra 1.79 1.73 1.85 1.71 0.080 1.99d 1.55e 0.056
10thrib 1.94 1.90 1.94 1.86 0.100 2.13d 1.69e 0.071
Longissimusmusclearea,cm2 42.2 42.9 43.4 41.9 0.85 42.2 42.9 0.60
Longissimusmusclecolorc 2.29 2.25 2.26 2.20 0.117 2.26 2.24 0.083
Longissimusmusclefirmnessbc
Barrow 2.15ef 2.30ef 2.73e 2.33ef 0.192 — — —
Gilt 2.40e 2.33ef 1.75f 2.20ef — — — —
Longissimusmusclemarblingc 1.43 1.41 1.15 1.14 0.112 1.36 1.21 0.079
Chemicalcompositionoflongissimusmuscle,%d
Moisture 73.16 73.34 73.42 73.23 0.140 73.12 73.45 0.099
Protein 23.39 23.35 23.13 22.92 0.241 23.33 23.06 0.170
Fat 2.77 2.78 2.46 2.83 0.160 2.79 2.62 0.113
ank603=transgenicRoundupReadycorn;RX670=nontransgeniccontrolcorn;RX740andDK647=conventionalcornhybrids.
bCornline×genderinteraction(P<0.05).
cEvaluatedon5-or6-pointscales.Color:1=lightto6=dark;firmness:1=softto5=veryfirm;marbling:1=devoidto6=abundant.
dBasedonasubsampleofthreepigsperpen.
e,f,g,h,iWithinatreatmentandaninteraction,meanswithoutacommonsuperscriptletterdiffer(P<0.05).
Carcass Characteristics also shown similar lean growth rates for barrows and
gilts.
There was no effect (P > 0.05) of corn line on any InStudy2,cornline×genderinteractions(P<0.05)
of the carcass measures taken in Study l (Table 7). were detected for ultrasound longissimus muscle area
Additionally, none of the TOBEC measurements dif- and cold carcass weight (Table 8). Barrows fed hybrid
fered(P>0.05)amongthecornlines(Table7).InStudy DK647 had lower (P < 0.05) longissimus muscle area
1,TOBECmeasurementsforhotcarcassweight,shoul- than those fed nk603, whereas gilts fed DK647 had
derweight,andtotalleanweightweregreaterforbar- greater longissimus muscle areathan those fed nk603
rowsthangilts.However,giltshadagreaterpercentage and RX740 (Table 8). However, there was no corn line
of primal cuts and percentage fat-free lean than bar- × gender interaction (P > 0.05) for longissimus muscle
rows(Table7).TheTOBECestimatesofprimalweights area measured on the carcass (Table 8). For barrows,
weresimilartothedirectlymeasuredwholesaleprimal there wasno effectof corn lineon cold carcassweight,
weights reported by Gu et al. (1992) and Cisneros et whereasgiltsthatwerefedhybridDK647hadheavier
al.(1996).Inaddition,Unruhetal.(1996)reportedthat (P<0.01)carcassweightsthanthosefedtheothercorn
when barrows and gilts were fed to an end weight of lines(Table8).However,therewasnocornline×gender
127kg,theprimalpercentagewasgreateringiltsthan interaction (P > 0.05) for dressing percent, suggesting
in barrows. In the current study, the higher shoulder that variation in cold carcass weight for gilts resulted
weightforbarrowswasaresultoftheirgreaterslaugh- from differences in live weight at slaughter.
terweightthangilts(121vs.112kg,respectively).Pre- Inbothstudies,barrowshadgreater(P<0.05)back-
vious studies have shown that at a similar slaughter fat thickness than gilts; however, there was no differ-
weight,giltsproducecarcasseswithagreaterpercent- ence (P > 0.05) between the genders for longissimus
ageofleanthanbarrows(Cromwelletal.,1993;Unruh muscleareameasuredonthecarcass(Tables7and8).
etal.,1996).Carcassfat-freeleangain,calculatedfrom The difference in backfat depth between barrows and
TOBEC measurements, was not affected (P > 0.05) by giltswassimilartotheresultsofCromwelletal.(1993)
eithergenderorcornline(Table7).Moststudieshave andHahnetal.(1995);however,inthoseexperiments,
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Transgeniccornfeedingtoswine 579
Table9.Leastsquaresmeansfortheeffectsofcornlineandgenderonlongissimusmusclequalityandcomposition—
Study l
Cornlineindieta Gender
Item nk603 RX670 DK647 RX740 SEM Barrow Gilt SEM
Numberofpens 6 6 6 6 — 12 12 —
Longissimusmusclequalitymeasurements
Marblingb 2.00 2.03 2.00 2.00 0.014 2.00 2.01 0.010
Firmnessb 2.08 2.22 1.93 2.08 0.096 2.04 2.12 0.068
UltimatepH 5.64 5.60 5.63 5.63 0.016 5.65d 5.61e 0.012
MinoltaL* 50.69 50.59 50.78 49.75 0.623 50.37 50.53 0.440
Minoltaa* 7.40 7.17 6.71 7.20 0.262 7.12 7.12 0.185
Minoltab* 2.58 2.51 2.39 2.11 0.294 2.43 2.37 0.208
Chemicalcompositionofthelongissimusmuscle,%c
Protein 23.51 23.78 23.48 23.74 0.216 23.77 23.49 0.153
Fat 2.99 2.20 3.06 3.08 0.247 3.08 2.59 0.174
Moisture 72.53 72.71 72.40 72.31 0.262 72.37 72.60 0.185
ank603=transgenicRoundupReadycorn;RX670=nontransgeniccontrolcorn;RX740andDK647=conventionalcornhybrids.
bEvaluatedusingafive-pointscale:1=softanddevoidofmarblingto5=firmandabundantorgreatermarbling.
cBasedonasubsampleofthreepigsperpen.
d,eWithinatreatmentandrow,meanswithoutacommonsuperscriptletterdiffer(P<0.05).
gilts had greater longissimus muscle area than bar- Musclequalityandcompositionmeasurementswere
rows, which is in contrast tothe results of the present generally similar (P > 0.05) for barrows and gilts in
studies.Thelackofagendereffectonlongissimusmus- both studies (Tables 8 and 9) with the exception that
cleareacould,inpart,beduetodifferencesinslaughter inStudy1ultimatepHvaluesweregreater(P<0.05)for
liveweightbetweenbarrowsandgilts.However,fitting barrows than gilts (Table 9); however, the differences
live weight at slaughter as a covariate in the model betweenthegenderswassmall.Mostpreviousstudies
removed the gender difference in carcass weight, but have indicated that meat quality measurements, in-
it did not produce a difference (P > 0.05) among the cluding ultimate pH, are similar for barrows and gilts
genders in longissimus muscle area. (Unruh et al., 1996; Nold et al., 1999).
Implications
Longissimus Muscle Quality
These studies demonstrated that the feeding value
In Study 1, there was no effect (P < 0.05) of corn
ofRoundupReadycorn(containingeventnk603,which
lineonanymusclequalityorcompositionmeasurement
expressestheCP4EPSPSprotein)issimilartothatof
(Table 9). Similarly, in Study 2, longissimus muscle
the nontransgenic control corn and the conventional
chemical composition and color and marbling scores
corn lines tested. Therefore, Roundup Ready corn
weresimilar(P>0.05)acrosscornlines(Table8).There
(eventnk603)whenusedinswinedietscanbeexpected
was an interaction (P < 0.05) between corn line and
tohaveeffectsongrowthperformanceandcarcasschar-
gender for longissimus muscle firmness. For barrows,
acteristics comparable to those of conventional corn.
there was no effect (P < 0.05) of corn line on muscle
firmness; however, gilts fed DK647 had lower scores,
Literature Cited
indicating softer muscle, than those fed nk603 (Table
8).Thereisnoobviousexplanationforthisinteraction. AOAC.1995.OfficialMethodsofAnalysis.16thed.Assoc.Offic.Anal.
GiltsfedDK647didgrowfasterthangiltsfedtheother Chem.,Arlington,VA.
corns (Table 6), but there were no treatment interac- Cisneros,F.,M.Ellis,F.K.McKeith,J.McCaw,andR.L.Fernando.
tions(P>0.05)formusclecolorscoresandfatcontent, 1996.Influenceofslaughterweightongrowthandcarcasschar-
acteristics,commercialcuttingandcuringyields,andmeatqual-
twofactorsthatcanbeassociatedwithmusclefirmness. ity of barrows and gilts from two genotypes. J. Anim. Sci.
Nevertheless, there was no evidence from these two 74:925–933.
studies of any negative effect of the test corn (nk603) Cromwell,G.L.,T.R.Cline,J.D.Crenshaw,T.D.Crenshaw,R.C.
Ewan,C.R.Hamilton,A.J.Lewis,D.C.Mahan,E.R.Miller,
onporkquality.ThisfindingissimilartothatofStani-
J.E.Pettigrew,L.F.Tribble,andT.L.Veum.1993.Thedietary
siewski et al. (2001), who reported no effects of a
proteinand(or)lysinerequirementofbarrowsandgilts.J.Anim.
RoundupReadycorn(eventGA21)comparedwithcon- Sci.71:1510–1519.
ventional hybrids on chemical composition of muscle. Forrest,J.C.,C.H.Kuei,M.W.Orcutt,A.P.Schinckel,J.R.Stouffer,
Pork quality is of increasing importance to the swine and M. D. Judge. 1989. Areview of potential new methods of
on-lineporkcarcassevaluation.J.Anim.Sci.67:2164–2170.
industry, and these results suggest no difference be-
Gu,Y.,A.P.Schinckel,andT.G.Martin.1992.Growth,development,
tweentheRoundupReadyhybridtestedrelativetothe
andcarcasscompositioninfivegenotypesofswine.J.Anim.Sci.
conventional corns for longissimus muscle quality. 70:1719–1729.
Downloaded from www.journalofanimalscience.org by guest on December 10, 2013