母(mu)雞(ji)開(kai)始(shi)產(chan)蛋(dan)的(de)年(nian)齡(ling)，依(yi)品(pin)種(zhong)而(er)異(yi)，約(yue)為(wei)五(wu)個(ge)月(yue)。開(kai)產(chan)以(yi)後(hou)，除(chu)少(shao)數(shu)個(ge)體(ti)外(wai)
，一(yi)般(ban)以(yi)第(di)一(yi)年(nian)的(de)產(chan)蛋(dan)量(liang)高(gao)

，自(zi)第(di)二(er)年(nian)以(yi)後(hou)，產(chan)蛋(dan)量(liang)即(ji)逐(zhu)漸(jian)降(jiang)低(di)。以來航型蛋用雞第一年的產蛋量為100%計算，第二、三、四、五年的產蛋量分別下降為 84%、72%、63%和55%。因此，將老齡雞留在群裏不淘汰

，對生產是不利的。現代商品性養雞場，一般是母雞產蛋12~14個月後即全部淘汰
，采用“全進全出”defangshi，jikeshijichangjingchangbaochijiaogaodeshengchanshuiping

，youbianyusiyangguanlihefangyi。zhezhongyangjichangshengchandeshangpindanbuzuozhongyong
，keyibuyanggongji。zhongjichang
，youshiweilejianshaoyuchengfeiyong，zaimujikuaijieshudiyigechandanshengwunianzhishi，jinxingqiangzhihuanyu，kezailiyongyiduanshiqi。zhongjichangzhongjidenianlingbiliyibanweiyinianzhan55%
，二年占33%，三年占12%。zhonggongjiyidiyinianhuolizuiqiang

，yibanzhiliyongyinian，yinglijitaotai，yimianlangfeisiliao。zhongjichangdeyouxiugongjiyoushikeliyongliangnian。rouyongzhongjiyindiernianchandanxiajiangjiaoduo，erqiejitizhongwangwangguoda，buliyuchandanpeizhong，yibanliyongdiyishengwuchandannianzhihouji64～68周齡即行淘汰。