摘要
用鸡减蛋综合征（ＥＤＳ－７６）郑州分离株（Ｚ１６）人工感染不同日龄ＨＩ抗体阴性的褐壳蛋鸡，除１０日龄雏组外均表现良好的抗体反应。攻毒后二周，１０，４０，７０，１２０，２００，３６０日龄各组鸡的ＨＩ抗体依次为２．７、６．３、９．７、９．８、８．９、９．０（ｌｏｇ２），２００，３６０日龄组鸡感染后出现典型的ＥＤＳ－７６症状，产蛋率分别下降４５％和１５％，但３６０日龄组异常蛋数量较少，恢复也快些。１２０日龄组无明显症状，但开产期推迟，亦有软、破蛋现象、用２００日龄组（罗曼品种）感染后２０～５０天内下的蛋作喂饲试验；均可使３／４阴性鸡出现７～９（ｌｏｇ２）抗体反应。３００日龄来航鸡感染后不见产蛋下降和蛋壳异常．但可检出８（ｌｏｇ℃２）左右的阳性抗体。用其感染后５～１５天内下的蛋饲喂阴性鸡，仅能使１／４鸡出现短暂的低抗体反应，表明对ＥＤＳ－７６病毒敏感性存在着品种差异。
Abstract Yuzhou Brown shell chickens and Roman chickens in different aSes were experimentally infected with the Zhengzhou Strain(Z16) of EDS-76 virus. The level of antibody against. EDSV in the expermentul group was increased significantly except for the 10--day-old chickens. Two weeks after infection, the aHI titers of antibody in the different ages of 10. 40. 7,0. 120. 200 and 360 days old were 2. 7、 6. 3、 9. 7、 9. 8、 8. 9and 9. 0(log2) respectivelly. The clinical symptoms of EDS--76 were typicallyOCcurred in the two groups-the 200-day-old and 360--day-old groups, and egg production dropped with a percentuSe of 45% and 15 % respectively. In the 360-day--old sroup', the abnormal eggs were fewer and the infected chickens recovered sooner. No obvious symptoms were observed in the 12Dday-old sroup, butthe onset of laying was delayed and some eggs were wth cracked and soft shell.When feedinS teSt was Performed with eggs laid within 20￣ 30 days by the 200-day-old infected chicken, three fourths of the negative feedins chickens had 7-9 (ic82 ) titers of antibody against EDSV. No egg droppins and aberrant egg was detected in the 360--day--old infected White leShorn chickens, but the titer of antibody against EDSV was 8(log2) negative. Chickens were fed with eggs laid within 5--15days by the 360--day--old infected white leghorn chicken,. the level of antibody was very 'low and only 1/4 chicken can be detected. The resultS indicated that the Sgnsitivity to EDSV in different Species is different.
