隨著外來雞(ji)(ji)種(zhong)(zhong)的(de)引(yin)進,我們(men)國(guo)雞(ji)(ji)的(de)生存空間大大減少(shao)。在農業部辦公(gong)廳關(guan)于(yu)印發(fa)《全國(guo)畜(chu)禽遺傳資源保護和利用(yong)“十(shi)三五(wu)”規劃》的(de)通(tong)知(zhi)中(zhong)列舉了,共計76個品種(zhong)(zhong)已(yi)經列入瀕危(wei)品種(zhong)(zhong)列表,其中(zhong)14種(zhong)(zhong)已(yi)認(ren)定(ding)滅絕的(de)畜(chu)禽品種(zhong)(zhong)中(zhong)就包括了煙臺糝糠雞(ji)(ji)、陜北雞(ji)(ji)2種(zhong)(zhong)國(guo)雞(ji)(ji)。
陜(shan)北(bei)雞產(chan)區位(wei)于(yu)陜(shan)北(bei)西(xi)部,屬溫帶干(gan)旱、半干(gan)旱溫帶大陸性季(ji)(ji)風(feng)氣(qi)(qi)(qi)候(hou)(hou),年平均降雨量400毫米左(zuo)右,年均氣(qi)(qi)(qi)溫8℃,無霜(shuang)期140天(tian)左(zuo)右,四季(ji)(ji)分(fen)明(ming),氣(qi)(qi)(qi)候(hou)(hou)多(duo)變,寒季(ji)(ji)長,熱天(tian)短,溫差大,富日照(zhao),少降水,多(duo)風(feng)沙。春季(ji)(ji)干(gan)旱多(duo)風(feng),夏季(ji)(ji)高溫多(duo)暴雨,旱澇相間,秋季(ji)(ji)雨水較多(duo),冬季(ji)(ji)寒冷干(gan)燥。在長期的飼養進化過程中,陜(shan)北(bei)雞逐步(bu)適應(ying)了(le)這種氣(qi)(qi)(qi)候(hou)(hou)。產(chan)區主(zhu)要農(nong)產(chan)品有綠豆、蕎麥、馬鈴薯(shu)、沙棘等,為(wei)陜(shan)北(bei)雞的生長提供了(le)充足的飼料來源。
陜北雞(ji)(ji)體型緊(jin)湊,身軀稍小,背平(ping)欠寬,頸部(bu)昂揚,尾羽高翹,羽毛緊(jin)貼,外貌清秀,行(xing)動靈活。頭較(jiao)小,呈橢圓形。喙(hui)稍長,略彎,呈灰白色及黑褐色。冠(guan)型單冠(guan)、玫瑰冠(guan)和豆冠(guan),以單冠(guan)居多(duo)。眼大(da)(da),微凸,有神(shen),虹彩多(duo)黃褐色。公雞(ji)(ji)肉髯大(da)(da),母雞(ji)(ji)肉髯較(jiao)小。耳(er)葉(xie)大(da)(da)小適中(zhong),呈紅(hong)色。白羽雞(ji)(ji)居多(duo),次為蘆花羽、黃羽、黑羽與麻羽雞(ji)(ji),大(da)(da)部(bu)分雞(ji)(ji)的皮膚為白色,少數為黃色,脛較(jiao)細,長短適中(zhong),大(da)(da)部(bu)分灰色。
公(gong)雞(ji)(ji)平(ping)(ping)(ping)均性成熟期(qi)180天(tian),母(mu)雞(ji)(ji)50%開產日(ri)(ri)齡(ling)(ling)(ling)225天(tian),300日(ri)(ri)齡(ling)(ling)(ling)平(ping)(ping)(ping)均產蛋(dan)45枚(mei),年產蛋(dan)125個,蛋(dan)重(zhong)(zhong)50克,蛋(dan)殼為白色和淺(qian)褐色兩(liang)種(zhong)。平(ping)(ping)(ping)均種(zhong)蛋(dan)受(shou)(shou)精(jing)(jing)率(lv)92%,平(ping)(ping)(ping)均受(shou)(shou)精(jing)(jing)蛋(dan)孵化(hua)率(lv)90%。母(mu)雞(ji)(ji)就巢性強(qiang),平(ping)(ping)(ping)均就巢持續期(qi)27天(tian)。陜北(bei)雞(ji)(ji)初(chu)生平(ping)(ping)(ping)均體重(zhong)(zhong)37克,180日(ri)(ri)齡(ling)(ling)(ling)成年公(gong)雞(ji)(ji)3斤8兩(liang),母(mu)雞(ji)(ji)3斤4兩(liang)。180日(ri)(ri)齡(ling)(ling)(ling)公(gong)雞(ji)(ji)平(ping)(ping)(ping)均半凈膛屠宰率(lv)78%,母(mu)雞(ji)(ji)77%,180日(ri)(ri)齡(ling)(ling)(ling)公(gong)雞(ji)(ji)平(ping)(ping)(ping)均全(quan)凈膛屠宰率(lv)70%,母(mu)雞(ji)(ji)68%。