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《Factors influenceing growth performance of beef bulls in a test station - Liu and Makarechian 1993 JAS 711123-1127》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、FactorsInfluencingGrowthPerformanceofBeefBullsinaTestStation'f2M.F.LiuandM.Makarechian3DepartmentofAnimalScience,UniversityofAlberta,Edmonton,Alberta,CanadaT6G2P5ABSTRACTPerformancerecordsof2,034beefaffectedperiodswereeither28to112dor56to112dbullstestedattheEllerslieTestStation,Alberta
2、,oftest.However,theeffectincreasedduringtheCanadafrom1974to1987wereanalyzedtoidentify112-to140-dperiod.Theeffectofherdoforiginonimportantfactorsthataffectgrowthofbullsinatestperiodicrelativegrowthratewaslargeandrelativelystationandtoestimatethecontributionofherdofstableupto84d,decrease
3、dduringthe84-toorigintophenotypicvariancesofgrowthtraits.112-dperiod:andincreasedduringthe112-toComparedwithherdoforigin,ageofdam,startoftest140-dperiod.Theeffectofherdoforiginoncumulativeage,andweightofbullwerenotofpracticalimpor-relativegrowthrateshowedanincreasingtrend.tance.Herdofo
4、riginaccountedforalargefractionofBecauseADGwashighlyinfluencedbyherdoforiginphenotypicvarianceofweight,decreasingfrom52toduringthefirst4wkoftestandleastaffectedduring35%andfrom37to30%fromstarttoendoftestinthe28-to112-dperiodorthe56-to112-dperiod,agroupsofsmallandlargebreeds,respectivel
5、y.The56-dadjustmentperiodfollowedbyan84-dtestperiodeffectofherdoforigmonperiodicandcumulativeforaccurateevaluationofbeefbullsforgrowthADGdecreasedasthetestadvanced.Theleastpotentialseemsappropriate.KeyWords:BeefBulls,StationTestsJ.him.Sci.1993.71:1123-1127Introductionweightatthestartof
6、testandconsequentlytovariationingainontest,whichwouldpersistuptotheStationperformancetestingallowsforthecompari-endofthetest.Ageofdamwasalsoafactoraffectingsonofbeefbullsfromdifferentherdsunderstandardpreweaninggrowthofcalvesandthatmight,there-conditionstoidentifygeneticallysuperiorbul
7、lsforusefore,affectpostweaninggrowthofcalvesontestincommercialherds.Foraccurateevaluationof(Simmetal.,1985;AmalandCrow,1987).Reportsongrowthpotentialofbeefbulls,itisnecessarytotheeffectofageofbullonpostweaninggrowthhaveidentifyimportantfactorsthataffectthegrowthofnotbeenconsistent(Ba
