Abstract: Avian leukosis，group of diseases designates a variety of transmissible benign and malignant neoplasms of chickens caused by members of the avian retrovirus family. Notably，Exogenous avian leukosis viruses （ALVs），including the subgroups A，B，C，D，J，and K has certain pathogenicity and has induced great economic loss to the poultry industry since 1990s. Vertical transmission via directly infected chicken embryos is the main transmission route，therefore，it is crucial to control avian leukosis virus by well eradication of vertical transmission of ALV in broiler breeder flock. In this study，we analyzed the positive incidence rate of ALV in two ALV well?eradicated broiler breeder flocks and their offspring，by virus isolation，egg albumen p27 detection，and pathological analysis. Our results showed that the ALV positive rate in different generations were really low，even close to zero，which strongly suggest that an excellent effect of good ALV eradication in broiler breeder flock will produce offsping with extremely low positive rate of ALV.

Key words: Avian leukosis, Nucleus flocks, Eradication

摘要： 禽白血病是由反转录病毒科禽反转录病毒属成员引起的各种可传播的良性和恶性 肿瘤的总称。其中，鸡的外源性禽白血病病毒包括A、B、C、D、J和K亚群，有一定的致病性。 从20世纪90年代以来该病给我国养殖业造成重大的经济损失。禽白血病病毒主要通过感染 的鸡胚从母鸡垂直传染给下一代，因此，做好核心群的禽白血病净化，阻断垂直传播是禽白血 病防控的关键。本研究对2个接近实现净化的核心鸡群及其后代通过病毒分离、蛋清检测、病 理切片等不同方法进行禽白血病监测。从监测结果看，不同代次核心群的外源性禽白血病病 毒阳性率极低，甚至为0；在核心群基本实现净化的条件下，后代鸡群可保持极低的阳性率。

关键词: 禽白血病, 核心群, 净化