家禽數(shù)量性狀的遺傳課件

家禽數(shù)量性狀的遺傳

肉用性狀（meattrait）的遺傳

蛋用性狀（eggtrait）的遺傳

繁殖力和生活力的遺傳

飼料報酬(feedremuneration)

家禽數(shù)量性狀的遺傳肉用性狀（meattrait）的遺傳肉用性狀（meattrait）的遺傳

體型大?。╞odysize）或體重（bodyweight）

出殼體重（day-oldweight）

生長期體重（growerweight）：6-7周齡體重h2=0.42-0.46

成年體重（adultweight）h2=0.55-0.65

肉用性狀（meattrait）的遺傳體型大?。╞ody肉用性狀（meattrait）的遺傳生長速度（growingrate）

累積生長（accumulategrowing）

絕對生長（absolutegrowing）

相對生長（relativegrowing）

早期生長速度h2=0.4-0.5

肉用性狀（meattrait）的遺傳生長速度（growin肉用性狀（meattrait）的遺傳Geneticparametersofgrowthcurveinchickens(S.Mignon-GrasteauandC.Beaumont,2019,7thWCGALP,11-3)Gompertzfunctionofgrowthcurve:Byusingdataof464chickensfromaslowgrowingmeat-typeline,whichwereweighedeverytwoweeksfrom4to16weeks,theGompertzcurvefittedwellthedata(R2=0.99),thegreatestdifferencebeinganoverestimationofbodyweightat10weeks(3.6%inmalesand2.8%infemales).肉用性狀（meattrait）的遺傳Geneticpar肉用性狀（meattrait）的遺傳肉用性狀（meattrait）的遺傳肉用性狀（meattrait）的遺傳Conclusion:Thisstudyconfirmedthatmalesandfemaleschickenscanbedistinguishedbytheirgrowthcurveparameters,femalesbeingmoreprecociousthanmales.GeneticparametersoftheGompertzfunctionparametersshowedmoderateheritabilities,makingitpossibletoselectdirectlyontheformofthegrowthcurve.肉用性狀（meattrait）的遺傳Conclusion:肉用性狀（meattrait）的遺傳屠宰率（dressedpercentage）

h2=0.2-0.6

肉用性狀（meattrait）的遺傳屠宰率（dressed肉用性狀（meattrait）的遺傳Geneticandphenotypicparametersofgrowthandcarcasstraitsofamalelineofbroilersraisedintropicalconditions(C.Argent?o1etal2019,7thWCGALP4-34)ThedatasetinformationcamefromamaleselectionlineofbroilersownedbyAgroceres-RossMelhoramentoGenéticodeAvesLtda.andraisedintropicalconditionsinfarmlocatedcloseto22oSand48oW,ataltitudearound700mabovesealevel.Growthdatacamefrom27,231maleandfemalebirdssubmittedtoselectionanddatasethadinformationon5generationsofpedigree;Carcassdatacamefrom9,463fullsibsofbroilersfromselection,thatwereprocessedattheexperimentalslaughterhouse.Thoseanimalswereslaughteredaround42daysofage,from2019to2019.肉用性狀（meattrait）的遺傳Geneticand肉用性狀（meattrait）的遺傳Traitsmeasured:W35:weightat35daysofage,us1:ultrasoundmeasurementsonbreastmuscledepth(measurednexttomiddleline);us2:ultrasoundmeasurementsonbreastmuscledepth(measuredtransversally);FC:feedconversion;LWS:liveweightatslaughter;HCW:hotcarcassweight;Breast:debonedandskinnedchilledbreastweight;Legs:chilledwholelegweight.Software:SAS,MTDFREML肉用性狀（meattrait）的遺傳Traitsmeas肉用性狀（meattrait）的遺傳肉用性狀（meattrait）的遺傳肉用性狀（meattrait）的遺傳肉用性狀（meattrait）的遺傳肉用性狀（meattrait）的遺傳Conclusions:TheanimalmodelREMLmethodseemedtobeeffectivetoestimategeneticparametersevenindataofselectedpoultry.Thegrowthandcarcasstraitsoftheselectedmalelineanalyzedcanbeusedasselectioncriteria,sincenoimportantgeneticantagonismwasobserved.Economicstudiesshouldbeappliedtothetraitsanalyzed,toidentifywhichcombinationofthemwouldmaximizeprofit.Asanindicatorofcarcassmeritatslaughter(42daysofage),liveweightseemedtobeagoodandeasytomeasureselectioncriterion,thatcanbewidelyused,asithasgoodgeneticcorrelationwiththeothertraitsandmediumheritability.肉用性狀（meattrait）的遺傳Conclusions肉用性狀（meattrait）的遺傳肉雞部分性狀的遺傳力

肉雞部分性狀的遺傳和表型相關(guān)

肉用性狀（meattrait）的遺傳蛋用性狀（eggtrait）的遺傳

產(chǎn)蛋量（eggproduction）

入舍蛋雞產(chǎn)蛋量（eggproductionH.H-hen-housed）：以開產(chǎn)時入舍母雞數(shù)為基數(shù)（包括開產(chǎn)后死亡、淘汰母禽在內(nèi)），在一定利用期內(nèi)的產(chǎn)蛋量。入舍母雞72周產(chǎn)蛋量h2=0.05-0.1飼養(yǎng)只日產(chǎn)蛋量（eggproductionH.D-hen-day）：根據(jù)每天平均飼養(yǎng)母禽數(shù)計算在一定時間內(nèi)的平均產(chǎn)蛋量。飼養(yǎng)只日72周產(chǎn)蛋量h2=0.23-0.27。

蛋用性狀（eggtrait）的遺傳產(chǎn)蛋量（eggpro蛋用性狀（eggtrait）的遺傳影響產(chǎn)蛋量的因素：

1、性成熟期(sexmaturity)：又稱開產(chǎn)日齡(ageatfirstegg)，指母禽產(chǎn)第一個蛋的日齡。有時用早熟性（earliness）來描述性成熟的早晚。

度量方法：個體，見第一個蛋的日齡；群體，蛋禽為達50%產(chǎn)蛋率的日齡，肉用禽為達5%產(chǎn)蛋率的日齡。性成熟期的h2=0.3

蛋用性狀（eggtrait）的遺傳影響產(chǎn)蛋量的因素：蛋用性狀（eggtrait）的遺傳2、產(chǎn)蛋強度（layingintensity）：指某一時間內(nèi)母禽的產(chǎn)蛋率（layingrate），可用一定時間內(nèi)該禽群的產(chǎn)蛋百分率表示。h2=0.1

3、產(chǎn)蛋持久性（layingpersistency）：一般以生物學(xué)年的長度表示，即從開產(chǎn)開始，經(jīng)產(chǎn)蛋高峰期、產(chǎn)蛋下降期到停產(chǎn)換羽為止所用的時間。

蛋用性狀（eggtrait）的遺傳2、產(chǎn)蛋強度（layin蛋用性狀（eggtrait）的遺傳4、就巢性（broodiness）：即抱性，為質(zhì)量性狀。

5、休止性（pause）：又稱冬休性（winterpause）。

產(chǎn)蛋持久性>產(chǎn)蛋強度>休止性>就巢性>性成熟期。

蛋用性狀（eggtrait）的遺傳4、就巢性（broodi蛋用性狀（eggtrait）的遺傳蛋重（eggweightoreggsize）

測量方法：國外一般32-36周齡中連續(xù)測定3天；我國學(xué)者建議295-300天內(nèi)取5天平均蛋重。h2=0.2-0.7。

蛋用性狀（eggtrait）的遺傳蛋重（eggweigh蛋用性狀（eggtrait）的遺傳蛋品質(zhì)（eggquality）

蛋殼品質(zhì)（shellquality）蛋殼形狀（shellshape）：用蛋形指數(shù)（eggindex）衡量，即縱徑/橫徑或橫徑/縱經(jīng)。h2=0.25-0.5蛋殼顏色（shellcolor）h2=0.3-0.9

蛋用性狀（eggtrait）的遺傳蛋品質(zhì)（eggqual蛋用性狀（eggtrait）的遺傳蛋殼品質(zhì)（shellquality）

蛋殼結(jié)構(gòu)（shelltexture）：用三個指標(biāo)，即蛋殼強度(shellstrength)、蛋殼厚度(shellthickness)和蛋殼平滑性(shellsmoothness)衡量。蛋殼強度用強度測定儀測定，分四級，正常應(yīng)在2-3級之間。蛋殼厚度可用厚度測定儀或千分尺測量，正常在244-373nm間，h2=0.3；也可用蛋比重（specificgravityofeggsoreggdensity）間接測量，正常比重在1.070-1.080間，h2=0.3-0.6。

蛋用性狀（eggtrait）的遺傳蛋殼品質(zhì)（shellq蛋用性狀（eggtrait）的遺傳2、蛋白品質(zhì)（qualityofeggwhite）

可用濃蛋白高度或轉(zhuǎn)換成哈夫單位（Haughunit）表示。HU=100lg(H-1.7W0.37+7.57)

濃蛋白高度h2=0.15-0.55；哈夫單位h2=0.1-0.7

蛋用性狀（eggtrait）的遺傳2、蛋白品質(zhì)（quali蛋用性狀（eggtrait）的遺傳3、蛋黃品質(zhì)（yolkquality）：用兩個指標(biāo)度量，即蛋黃顏色和蛋黃占全蛋的比例。蛋黃顏色用羅氏比色扇測定，共分15級（由淺黃到深黃），正常應(yīng)為12級以上。h2=0.15正常蛋蛋黃約占全蛋30-35%（殼，10-12%；蛋白，55-60%）h2=0.1-0.4

蛋用性狀（eggtrait）的遺傳3、蛋黃品質(zhì)（yolk蛋用性狀（eggtrait）的遺傳4、血斑或肉斑（bloodspotsormeatspots）種蛋容許率<2%，h2=0.1-0.5

蛋雞部分性狀的遺傳力

蛋用性狀（eggtrait）的遺傳4、血斑或肉斑（bloo蛋用性狀（eggtrait）的遺傳Estimationofgeneticparametersforclutchtraitsinlayinghens(Y.Akbasetal.,2019,7thWCGALP04-15)GeneticStock.eggproductiondataofacommercialsirelineat6thgeneration.Data.Thedatacollectionperiodwasfromthe22ndto40thweeksofage.Henswereartificiallyinseminated.Intotal1980animalswereusedfrom43siresand8damspersire.Traitsrecorded:EN,,eggnumbersto40weeksofageforeachindividual.CN,clutchnumber.CS,averageclutchsize.Clutchsizeconsistsofnumberofdayswithconsecutivelylaideggs.Atleastone-day-breakofovipositionwastakenastheendofaclutch.DELAY,meandelayofpausedaysbetweenclutches.ASM,Ageatsexualmaturity.BWSM,bodyweightatsexualmaturityage蛋用性狀（eggtrait）的遺傳Estimationo蛋用性狀（eggtrait）的遺傳StatisticalAnalyses.Model:Yijklisanytraitconsideredinthisstudy,μ

istheoverallmean,

fi

isthefixedeffectoftheithtier,

sjanddk(j)arerandomeffectsofthesireanddamwithinsires,βistheregressioncoefficient,xisageatsexualmaturityasacovariate,eijkistheresidualeffect.VariancecomponentsforthetraitswereestimatedbyRestrictedMaximumLikelihood(REML).蛋用性狀（eggtrait）的遺傳Statistical蛋用性狀（eggtrait）的遺傳Results:蛋用性狀（eggtrait）的遺傳Results:蛋用性狀（eggtrait）的遺傳蛋用性狀（eggtrait）的遺傳蛋用性狀（eggtrait）的遺傳Higherheritabilityestimatesfromdamcomponentascomparedtoestimatesfromsirecomponentsuggestthatsomematernalandnon-additiveeffectsaresignificantforthetraits.CS,ENandCNarehighlycorrelatedtraitswitheachother.CShasgeneticcorrelationsof-0.98,0.82and0.58withCN,ENandDELAY,respectively.CNisnegativelycorrelatedwithothertraitsconsidered.HighheritabilityofCNandCSindicatethatthesetraitsmaybeusedintheselectionindexoflayinghensbecausethosetraitsarealsohighlycorrelatedwithEN.蛋用性狀（eggtrait）的遺傳Higherherit繁殖力和生活力的遺傳

繁殖力（reproductivecapacity）——家禽繁殖后代的能力。

1、受精率（fertilitypercentage）h2=0.05

繁殖力和生活力的遺傳繁殖力（reproductiveca繁殖力和生活力的遺傳孵化率（hatchability）h2=0.1-0.15

繁殖力和生活力的遺傳孵化率（hatchability）繁殖力和生活力的遺傳

生活力(viability)——在一定外界環(huán)境條件下的生存能力。1、育雛率（broodedpercentage）h2=0.05

繁殖力和生活力的遺傳生活力(viability)——在一定繁殖力和生活力的遺傳

2、存活率（survival）：h2=0.05-0.1

繁殖力和生活力的遺傳2、存活率（survival）：h2=飼料報酬(feedremuneration)

飼料消耗比（feedconsumptionratio）h2=0.2-0.6

飼料轉(zhuǎn)化效率（feedutilizationefficiency）：飼料營養(yǎng)物被家禽轉(zhuǎn)化用于生產(chǎn)產(chǎn)品的百分率。

Geneticevaluationoffeedefficiencytraitsinawhiteleghornpopulation(R.C.Hazary,etal.,2019,7thWCGALP,10-18)

飼料報酬(feedremuneration)飼料消耗比（飼料報酬(feedremunerationPopulationandselectionmethod.TwoWhiteLeghornpopulationsviz.IWKandControlmaintainedasclosedflockatExperimentalFarm,ProjectDirectorateonPoultry,Hyderabad,Indiawasutilizedinthepresentstudy.TheIWKlinewaspreviouslyselectedforincreasedeggproductionupto64weeksofageusingafamilyindex.TheControllinewasmaintainedasarandombredpedigreedpopulation.Bothlineswerereproducedsimultaneouslyandwererearedunderidenticalconditionsoffeedingandmanagement飼料報酬(feedremunerationPopulati飼料報酬(feedremunerationTraitsmeasured.Theindividualtraitsmeasuredincludedbodyweight(g)measuredatfourweeklyintervalstartingfrom20weeksofage;averageeggweight(g)at24,28,32,36and40weeksofage;eggproductionupto20,21-24,25-28,29-32,33-36,37-40andupto40weeksofage;feedconsumption(g)from21-24,25-28,29-32,33-36,37-40and21-40weeksofageandageatsexualmaturity(days).Utilizingtheaboveinformationfeedconsumedperday(g),feedconsumedperdozenegg(g)andfeedconsumedperkilogramofeggmass(g)werederivedintheentiretestperiodsaswellasonoverallperiod.Residualfeedconsumptionwasonlyestimatedin21-40weeksperiodasdifferencebetweenexpectedfeedconsumptionandactualfeedconsumption.飼料報酬(feedremunerationTraitsm飼料報酬(feedremuneration飼料報酬(feedremuneration飼料報酬(feedremuneration飼料報酬(feedremuneration飼料報酬(feedremuneration飼料報酬(feedremuneration飼料報酬(feedremunerationCONCLUSIONTheresultsclearlyshowthatthelineselectedforincreasedeggproductionismoreefficientinutilizationoffeedascomparedtocontrol.Residualfeedconsumptionisalowlyheritabletraitinthislinesuggestingthatitcannotbeutilizedasaselectioncriteriontoenhanceefficiencyofeggproduction.Itwillbemoreappropriatetoselectonthebasisoffeedconsumedperkilogrameggmassproductionthatwillnotonlytakecareofeggproductionbecauseofitsfavorableassociationwitheggproductionbutalsoforeggweightsinceitisoneofthecomponenttraits.Geneticcorrelationsofpartperiodeggproductionwithfeedefficiencytraitsintheselectedlinewereingeneralnegativeindicatingthatanyattempttoimprovefeedefficiencywouldresultinimprovementineggproductionefficiency.飼料報酬(feedremunerationCONCLUSI飼料報酬(feedremuneration)

剩余飼料消耗（residualfeedconsumption）：實際耗料量與據(jù)總產(chǎn)蛋量、體重和體增重計算出的理論耗料量之差。h2=0.42-0.62

例：據(jù)NRC標(biāo)準(zhǔn)，ME11.7MJ/kg的日糧，理論耗料量為：E(FC)=46.5BW0.75+0.7EM+1.97BWGRFC=FI-E(FC)

飼料報酬(feedremuneration)剩余飼料消耗飼料報酬(feedremuneration)Residualfoodconsumptionasatooltounravelgeneticcomponentsoffoodintake(M.Tixier-Boichardetal.,2019,7thWCGALP,10-06)Theconceptofresidualfoodconsumption(RFC)wasfirstproposedbyByerly(1941)asanapproachtolimitfoodcostsinthelayinghen.Thepossibilitytoselectonthefractionoftotalfoodintakewhichisnotexplainedbymaintenancerequirementsandproductionwas,indeed,anappealingwaytomodifyfoodefficiencywithoutanychangeinproduction.Thiswasfirstinvestigatedinpoultry,forthelayinghenratherthanforthebroiler,and,later,inmammals.Extensivedatahavebeenobtainedsince30yearsonresponsestoselectiononRFCinthelayinghen,includingmetabolicstudies,and,morerecently,QTLdetection.飼料報酬(feedremuneration)Residua飼料報酬(feedremuneration)Predictionequation.Theclassicalpredictionequationisalinearmultipleregressionofobservedfoodintake(FI)ontwotypesofcomponents(1)bodyweight(BW)ormetabolicbodyweight,correspondingtomaintenancerequirement,(2)bodyweightgain(BWG)whichmaybepartitionedin‘proteingain’and‘fatgain’,and/or‘exported’productsuchaseggoutput,correspondingtoproductionneeds.Aninterceptisgenerallyincluded.RFC=FI-E(FC)E(FC)=a+b1WG+b2EM+b3BW0.75

E(FC)=Expectedfeedconsumption.(gm/d)

WG=Weightgain(gm/d)EM=Eggmassproduction(gm/d)BW0.75=Metabolicbodyweight(g)b1,b2,b3=Multipleregressioncoefficienta=Constant.Fixedeffectsmaybeaddedinadditiontothecovariables,inordertotakeintoaccounteffectsofseason,litter,orsex.飼料報酬(feedremuneration)Predict飼料報酬(feedremuneration)Metabolicbodyweightisobtainedasapowerofbodyweight,themostfrequentlyusedvaluebeing0.75.Inthelayinghen,thepowervaluemayvaryintherangeof0.5to1withoutaffectingtheefficiencyoftheprediction,andbodyweighthasbeenshowntobeanimportantsourceofvariationinfoodintake.Inthegrowingpig,however,performancerecordingisoftendoneatafixedbodyweight,andinthatcase,metabolicbodyweightdoesnotcontributesignificantlytovariationinfoodintake,butbackfatthickness,and/orloineyeareahavebeenconsideredasadditionalpredictorsofFI.飼料報酬(feedremuneration)Metabol飼料報酬(feedremuneration)Anothertypeofpredictortobeaddedcouldbeheatproduction.Indeed,fromthepointofviewofbioenergetics,metabolizableenergyisafunctionof(1)heatproduction,(2)energyretainedasproteinand(3)energyretainedasfat.Thus,heatproductionisanobviouscomponentoffoodefficiency.Whenheatproductionwasaddedinthepredictionequationoffoodintakeinthelayinghen,theresidualvariationwassignificantlydecreased,andthisdecreasedependedontheambienttemperatureandonthefeathercoverofhens,whichisalsoanimportantparameterforheatdissipation.飼料報酬(feedremuneration)Another飼料報酬(feedremuneration)Efficiencyofthepredictionequation.Theresidualvariationinfoodintakewhichisnotexplainedbyvariationinbodyweightandproductionlevelmayrepresentfrom10%to50%ormoreofthetotalvariation,accordingtospecies,breed,sex,age,andenvironment.Regressioncoefficientsonthedifferentpredictorswillvaryaccordingtothesamefactors.Patternsofenergyexchangeduringgrowthmaybecomparedbetweenspecies,usingmetabolicweightasareference,forinstance,maximalenergeticefficiencywasshowntobereachedat20%ofmaturebodysizeformammals,whereasthismaximalvaluewassustainedtoahigherdegreeofmaturityforbroilerschickensorquails.ThismayhaveimplicationsregardingthemostsuitableperiodtomeasureRFCduringgrowth,accordingtospecies.飼料報酬(feedremuneration)Efficie飼料報酬(feedremuneration)Withinallspecies,RFCdependsonthebreed,forexample:Island-Red(RIR)layersandWhiteLeghorn(WL)layersshoweddifferentregressioncoefficients,explainedbydifferentmaintenancerequirements,RIRshowedhigherbodyweight,%bodyfat,and%yolkintheegg,resultinginahigherenergycontentintheeggmass.Differenceswerealsoobservedwithinbreedbetweenselectedlines,forinstance:Inpigs,theLandracebreedwasfoundtohaveahigherRFCascomparedtoYorkshireandDurocbreedsortoLargeWhitebreed.CrossbreedingeffectsonRFCarenotwelldocumented;onestudyonlayinghens,obtainedfromcrossinghighandlowRFClines,showednoreciprocaleffectandanegativeheterosis,moderatebutsignificant(-3.6%),onRFC.飼料報酬(feedremuneration)Within飼料報酬(feedremuneration)Theeffectofsexhasnotbeenstudiedtothesameextentacrossspecies.Inpigs,dataaregenerallyobtainedonboarsonly.Incattle,bothsexeshavebeenmeasuredbutdatahavegenerallybeenpooledtoestimategeneticparameters.Inthelayinghen,selectionhasgenerallybeendoneonfemaleRFCrecords,but,inadultmalechickensofacommercialwhite-egglayingstrain,theregressiononBWandBWGonly,explainedonly53%oftotalvariationinFI,muchlessthanthatusuallyobservedwithafullmodelinfemales.InthesingleexperimentwhereRFCwasmeasuredandselectedindependentlyinadultsofeachsexthegeneticcorrelationbetweenthemaleRFCandthefemaleRFCwas0.19,notsignificantlydifferentfromzero.

飼料報酬(feedremuneration)Theeff飼料報酬(feedremuneration)Ageatmeasurementisafactortobeconsideredattwolevels:(1)timeofmeasurementascomparedtosexualmaturity,and(2)lengthofrecordingperiod.InchickenlinesselectedonRFCofthelayinghen,alowphenotypiccorrelation(0.34)hasbeenfoundbetweenadultRFCandfoodefficiencyofthegrowingchick,andnodifferencewasfoundbetweenfoodefficiencyofgrowingchicksfromtwolinesdivergentlyselectedonadultRFC.Intheselines,divergenceonRFCwasshowntotakeplacepreciselyatthetimeofsexualmaturity.Independentstudiesofthelengthofrecordingperiodinthelayinghenshowedthatashortperiod,suchas4weeks,startingafterthepeakoflay,wasagoodcompromisebetweenaccuracyofpredictionandcostofmeasurement.Aslightdecreaseintheregressioncoefficientoneggmassandamarkeddecreaseofthecoefficientonbodyweightgainwerefoundwithincreasingageinlayinghens.飼料報酬(feedremuneration)Ageat飼料報酬(feedremuneration)ThemostrelevantenvironmentalfactorstobeconsideredfortheefficiencyofRFCestimationaretemperatureandfoodcomposition.HighambienttemperatureisknowntodecreaseRFCinpigsandgenotypexenvironmentinteractionsaretobeexpectedwhenlineswithhighorlowRFCarecomparedattwotemperaturesinthelayinghen.AlowenergydiethasbeenshowntodecreaseRFC,andahighproteincontentisexpectedtodecreaseRFC.DifferencesbetweenlayinghensdivergentlyselectedonRFCweremaintainedwhenproteincontentofthedietwasmodified,butperformanceofhighRFChenswasmoreaffectedbyalowerproteincontentthanperformanceoflowRFChens.Foodspillagemustbeavoided,obviously,tomeasureadlib.foodintake,butdifferencesinfeedingbehaviorbetweenlinesorbetweenindividualsmaycausesomedifficultyinthedesignoffoodrecordingsystems.飼料報酬(feedremuneration)Themos飼料報酬(feedremuneration)GeneticvariabilityofRFC飼料報酬(feedremuneration)Genetic飼料報酬(feedremuneration)Heritabilitywouldappear,however,tobeslightlylowerforRFCmeasuredingrowinganimals(broilers)thaninadults(layinghen)withinthesamespecies.RFCisalwayspositivelycorrelatedwithtotalfoodintake,acrossspecies,startweightandweightgain.GeneticcorrelationsofRFCwithitsphenotypicpredictorsareofgreatinterestinlayinghens,correlationsbetweenRFCandBWoreggmassaregenerallylow,andinthedesirabledirection.Inbroilers,RFCwasnotcorrelatedwithitspredictor,startweightandweightgain.飼料報酬(feedremuneration)Heritab飼料報酬(feedremuneration)CorrelatedresponsestoselectiononRFCHeatproduction(HP).

Anatomicalmeasurementsrelatedtoheatdissipation,suchasshankandwattlelengthinthelayinghen,weremodifiedbyselectiononRFC.SignificantdifferenceswerealwaysfoundbetweenhighandlowRFClines,representinga23%increaseoftotalHPforfemales.SamplingWhiteLeghornhensonextremelyhighorlowRFC,inasinglegeneration,revealedadifferencerangingfrom10to30%intotalHPacrosstworeplicates.ThemaincomponentofthedifferenceinHPwasfoundtobeDiet-InducedThermogenesis(DIT),activity-relatedHP,andnotbasalmetabolicrate.飼料報酬(feedremuneration)Correla飼料報酬(feedremuneration)Behavior.HighandlowRFCchickenlinesdifferedforarangeofbehavioraltraits,suchaswalking,pacing,oraggressivity,andhensfromthelowRFClinewerealwaysmorequietandspentmoretimerestingandsleeping.TotalactivitywasalsolowerinhensofthelowRFCline,whichshowedalsoless‘frustration’behavior,itwassuggested,however,thatefficienthensmaystillbesusceptibletostressbutmayexhibitlessbehavioralpossibilitiestocopewithstress.ThestudyoffoodintakepatternshowedahighernumberoffoodaccessperiodsforhighRFChensbutnodifferenceinthetotaltimespenteating,similarly,highRFCmalesspentthesametimeeatingthanlowRFCmales,butatebiggermeals,particularlyjustattheonsetoflight.HighRFChenswereparticularlysusceptibletofooddeprivationatmolting.飼料報酬(feedremuneration)Behavio飼料報酬(feedremuneration)Bodycomposition.Theselectionexperimentswhichwereconductedonadultchickens,showedalowerbodyfatnessinthehighRFClines.Therelativedifferenceinfatnessbetweenlinescouldvaryfrom3to100%ofthemeanfatnesslevel,highestrelativedifferenceswerefoundbetweenhighandlowlinesofRIRchickens.Itmustbenoticedhowever,thatfatnessonthelowRFC,highefficientline,couldnotbeconsideredgenerallyasexcessive,butratheratanormallevel,whereasfatnessofthehighRFClinewasreallyabnormallylow.ExpressionoflipogenesisgeneswasalsofoundtodifferbetweenhighandlowRFClines.Furthermore,fatnesswasalsofoundtobelowerinyoungchicksfromtheRIRlinesselectedattheadultstage.Interestingly,inchickens,thehighRFClineshowedahigherproportionofviscerainfemalesonly,withasignificantlinexsexinteraction.飼料報酬(feedremuneration)Bodyco飼料報酬(feedremuneration)Reproductionandfertility.Inthechicken,fertilityandhatchabilityweresignificantlyd