%0 Journal Article %T PurelineselectionofJinyangⅢstraininlate-featheringLeghorn %A 赵德燕 %A 李温 %A 田水仙 %A 段栋梁 %A 吴忻 %J 华北农学报 %P 130-134 %D 1993 %R 10.7668/hbnxb.1993.S2.023 %X 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. %K chicken %K JinyangwhiteLeghorn %K latefeathering %K selection %U http://www.hbnxb.net/CN/abstract/abstract6475.shtml