SWINENUTRITIONGUIDEGROW-FINISHNUTRITION

ProteinandFatDeposition

Arelationshipexistsbetweenproteindepositionandenergyintakeinregardtogrow-finishgrowthperformance.Thisrelationshipchangesindifferentstagesofgrow-finishasthepigbecomesheavierandunderstandingthischangeallowsforthedevelopmentofnutrientrequirements.

EnergyforMaintenancevs.GrowthDietaryenergyisutilizedformaintenanceandgrowth.

Maintenanceenergyrequirementsaretheamountofenergyneededforbasalmetabolicfunctionsandtomaintainbodyweight(Velayudhanetal.,2015).Undernormalgrowingconditions,aftermaintenanceneedsaremet,pigswillprioritizeleantissuedepositionandthendirectnutrientstowardsfatdeposition(Bikkeretal.,1996).Therefore,arelationshipexistsbetweenenergysupplyabovemaintenancerequirementsandproteinandfatdepositionrates.

EnergyIntakeandProteinDepositionRelationshipTwodifferentphasesofgrowthexistinthegrow-finish

periodthatdescribestheinfluencesofdietaryenergyintakeonproteindeposition.Earlyinthegrowingperiod,alinearrelationshipexistsbetweendietaryenergyintakeandproteindeposition(CampbellandTaverner,1988;Bikkeretal.,1994).Thisrelationshiprevealsthatincreasingdietaryenergyintakeundernon-limitingaminoacidconditionswilllinearlyincreaseproteindepositioningrowingpigsuptotheirupperlimittoproteindeposition(PDmax)andthenplateau(Figure1).Thisindicatesthatpigsareinanenergydependentperiodofgrowth.BodyproteinincreaseslinearlywithenergyintakeuntilthePdmaxisreached(Bikkeretal.,1996).IncreasesinenergyintakeabovethatneededforPdmaxwillincreasetherateoflipiddepositionandcanresultinfattercarcassesandpoorerfeedefficiency.

Figure1.Relationshipbetweenproteindeposition(g/d)andMEintake(kcal/day)ingrowinggiltsatdifferentbodyweights(NRC,2012).

Althoughincreasingdietaryenergyintakecanincrease

proteindepositioningrowingpigs,thephysicalcapacityforfeedintakelimitsdietaryenergyintakeandthusproteindeposition.Conversely,increasingdietaryenergyintakeinpigsduringthelatefinishingphaseofproductioncanleadtoincreasesinlipiddepositionversusproteindeposition(Figure2).

Figure2.Lipiddepositiontoproteindepositionratio(g/g)atdifferentenergyintakesin2differentweightrangesofpigs(Bikkeretal.,1996).

Thisobservationcanbeexplainedinthechangesinbodycompositionasapigages.Therateoflipidaccretionrapidlyincreasesaspigsenterthelatefinishingphaseofproductionwhileleantissueaccretionratesstayrelativelyconstant(Figure3).

Figure3.Changesinchemicalbodycompositionwithincreasingbodyweight(AdaptedfromWagneretal.,1999).Thisphaseofgrowthisconsideredtheprotein

dependentphasebecauseenergyintakenolongerlimitsproteindeposition.

Limitingenergyintakeinearlyphasesofthegrow-finishperiodcannegativelyaffectproteindepositionandgrowth,butoverfeedingenergyinlaterperiodscanleadtoincreasesinlipidaccretion.Understandingthishelpsaidindeterminingthenumberofdietaryphasesusedinthenutritionalprogram,theweightrangesofthesedietaryphases,andnutrientrequirementsinanefforttomaximizeproteindepositionandoptimizeeconomicsuccess.

GenderDifferencesGendershouldbetakenintoconsiderationwhen

developingnutrientrecommendationsasenergyintakeandproteindepositionbetweenbarrowsandgiltsdiffer(Figures4,5).

Figure4.TypicaldailyMEintakesofbarrowsandgiltsbetween45and310lb(AdaptedfromNRC,2012).

Figure5.Typicalwhole-bodyproteindepositioncurvesingiltsandbarrowsbetween40and320lb(AdaptedfromNRC,2012).

Metabolizableenergy(ME)intakeisgreaterinbarrowsinthegrow-finishstageversusthatofgiltswhiletheproteindepositionratesaregreateringiltsthanbarrows.

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GeneticDifferencesUnderstandingPdmaxallowsforarelationshiptobe

establishedbetweenenergyintakeandbodyproteindepositionatvariousstagesofthegrow-finishperiodinaproductionsystem(deLange,2001).Geneticlinebeingusedshouldbetakenintoconsiderationasdifferentgenotypesexhibitdifferentproteinaccretionratesatdifferentbodyweights(Figure5).

Figure5.Differencesinproteinaccretionratebetween4differentgeneticlines(SchinckelanddeLange,1996).

DifferentgeneticlineswillreachPDmaxatdifferentpointsinthegrow-finishperiod.AfterPdmaxisreached,ratesofproteinaccretiondecline.Ingeneral,geneticlinesselectedforhighproteinaccretionwillreachPdmaxatheavierweightsandtherateofproteinaccretiondeclinewillbelessthangeneticlinesselectedforaverageorlowproteinaccretion.Furthermore,undercommercialconditions,grow-finishpigscanbeexposedtonumerousenvironmentalstressors.Geneticlineswillresponddifferentlytoenvironmentalstressorssuchashighstockingdensity,heatstress,disease,etc.andthiscansignificantlylimitexpressionoftheirtruegeneticpotentialforPdmax.Duetothis,producersshouldunderstandtheenvironmentalconditionsoftheirproductionsystemsothattheycanbetterunderstandtheirspecificproteinaccretionratesanditsrelationshipwithenergyintaketoestablishnutrientrequirements.

Insummary,arelationshipexistsbetweenenergyintakeandproteindeposition.Limitingenergyintakeinearlyphasesofthegrow-finishperiodcannegativelyaffectproteindepositionandgrowth,butoverfeeding

energyinlaterperiodscanleadtoincreasesinlipidversusproteinaccretion.Producersshouldalsounderstandthatdifferencesintheexpressionofthisrelationshipexistbetweengenderandgeneticlinesandmustbeconsideredwhendevelopingnutrientrequirements.

ReferencesBikker,P.,Verstegen,M.W.A.andR.G.Campbell.1996.

Performanceandbodycompositionoffinishinggilts(45to85kilograms)asaffectedbyenergyintakeandnutritioninearlierlife:II.Proteinandlipidaccretioninbodycomponents.JournalofAnimalScience.74:817-826.doi:10.2527/1996.744817x

Bikker,P.,Verstegen,M.W.A.,Campbell,R.G.andB.Kemp.1994.Digestiblelysinerequirementofgiltswithhighgeneticpotentialforleangain,inrelationtothelevelofenergyintake.JournalofAnimalScience.72:1744-1753.doi:10.2527/1994.7271744x

Campbell,R.G.andM.R.Taverner.1988.Genotypeandsexeffectsontherelationshipbetweenenergyintakeandproteindepositioningrowingpigs.JournalofAnimalScience.66:676-686.doi:10.2527/jas1988.663676x

DeLange,C.F.M.,Marty,B.J.,Birkett,S.,Morel,P.andB.Szkotnicki.2001.Applicationofpiggrowthmodelsincommercialporkproduction.CanadianJournalofAnimalScience.81:1-8.doi:10.4141/A00-006

NRC.2012.Nutrientrequirementsofswine.11threvisededition.Natl.Acad.Press.,WashingtonD.C.

Schinckel,A.P.andC.F.M.DeLange.1996.Characterizationofgrowthparametersneededasinputsforpiggrowthmodels.JournalofAnimalScience.74:2021-2036.doi.org/10.2527/1996.7482021x

Velayudhan,D.E.,Kim,I.H.andC.M.Nyachoti.2015.Characterizationofdietaryenergyinswinefeedandfeedingredients:Areviewofrecentresearchresults.AsianAustralianJournalofAnimalScience.28:1-13.doi:10.5713/ajas.14.0001R

Wagner,J.R.,Schinckel,A.P.,Chen,W.,Forrest,J.C.andB.L.Coe.1999.Analysisofbodycompositionchangesofswineduringgrowthanddevelopment.JournalofAnimalScience.77:1442-1466.doi.org/10.2527/1999.7761442x