三群商品代蛋鸡J亚群白血病跟踪观察

Continuous Observation of Subgroup J Avian Leukosis for Three Groups of Commercial Layer Chicken

【目的】了解J亚群白血病在海兰褐蛋鸡群中发生和发展的真实表现及其与病毒分离和抗体反应的关系;【方法】对来自3个鸡场39至43周龄31只疑似ALV-J感染鸡做了连续两个月的临床、病理、病毒血症和抗体反应动态观察和比较;【结果】这3群鸡对ALV-J感染率非常高,有28只鸡在死前感染ALV-J或呈现持续性病毒血症,其中14只表现为无抗体反应的免疫耐受性持续性病毒血症。这3群鸡都表现为典型J亚群白血病髓细胞样肿瘤特征性病变,且在几乎所有不同脏器和组织均可出现。在31只鸡中,有13只鸡同时在3个或3个以上不同脏器中出现肿瘤/血管瘤,有1只鸡出现在5个器官中;【结论】中国近年来不仅仍有ALV-J在蛋鸡群中流行,而且在过程中,ALV-J致病性逐渐增强。

[Objective] The objective of the study is to understand the occurrence and development of subgroup J avian leukosis in the commercial layer chickens as well as the relationship with the isolation of the virus and antibodies. [Method] Thirty-one chickens suspectable of ALV-J at the age of 39 to 43 weeks from 3 groups were observed and compared continuously in clinical status, pathology, viremia and development of neutralizing antibodies. [Result] It indicated that the infection rate with ALV-J in these three groups was very high. Twenty-eight chickens were infected with ALV-J or had persistent viremia, of which 14 were detected as immunotolerized persistent viremia without neutralizing antibodies. Indicative myelocytomatosis of ALV-J was found in chickens of these 3 groups, and could be detected in almost all of the organs and tissues. Of these 31 chickens, 13 had tumor/hemangioma in three or more organs and 1 chicken had in at least 5 organs. [Conclusion] Result of this observation indicates that ALV-J is still epidemical in Chinese commercial layer chickens, and the virus is getting stronger during the epidemic.