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华北农学报 1993
PurelineselectionofJinyangⅢstraininlate-featheringLeghornDOI: 10.7668/hbnxb.1993.S2.023, PP. 130-134 Keywords: chicken,JinyangwhiteLeghorn,latefeathering,selection Abstract: JinyangⅢstrainoflate-featheringLeghornchickenhasbeensuccessivelyselectedwithcomprehensiveindexfor7generationsbyfamilybreedingmethodofmass-firstandclosing-late.Ascomparedwiththecontrol,theselectionresultisaverage7daysearlieratfirstlayingforeverygeneration,morethan13ofeggnumberatageof300daysandhigherthan0.63%forsur-vivalrateinlayingperiod.Mainlayingperformancesareasfollows:ageatfirstlaying156±10.4days;eggnumberatageof300days99±26.O;eggnumberandeggweightat72weeksofage226±38.8and58.2±4.6grespectively.Throughcrossbreedingselection,aseriesofwhite-shellau-tosexingchickenhasbeendeveloped.Morethan5.1millioncommercialsex-identifiedchickenhavebeenreleasedaswell.
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