马立克氏病毒京-1株对不同日龄SPF鸡的致病力试验

将60羽SPF鸡随机分为3组,选取马立克氏病毒标准毒株京-1株分别对10日龄组和21日龄组鸡进行人工感染试验,对照组注射同等剂量的稀释液。结果显示：两组攻毒组试验鸡均于接种病毒后18d开始发病,并于20～25d出现死亡高峰,26d开始逐渐缓解。两组鸡的死亡率分别为80%和60%,肿瘤发生率分别为80%和65%,肿瘤主要出现在心脏、肝脏、脾脏、肾脏和坐骨神经等组织,其中10日龄攻毒组2～3个器官发生肿瘤的个体占65%,4个及以上器官发生肿瘤的个体仅占5%,21日龄攻毒组2～3个器官发生肿瘤的个体仅占35%,4个及以上器官发生肿瘤的个体达到20%。由此说明,10日龄SPF鸡对京-1株MDV敏感,而21日龄该品系鸡对之敏感性略低。

The Pathogenicity of MDV J-1 Strain to SPF Chickens at Different Day Ages

Sixty SPF chickens are divided randomly into three groups.Two groups of chickens,of 10 days old and 21 days old respectively,are challenged with MDV J-1 strain.The chickens of the control group are injected with the same volume of diluent.The results indicate that the clinical signs of the two challenged groups all occur on the 18thday after infection.The death peak appears from the 20thday to the 25thday,and gradually relieves on the 26thday.The mortalities of the two challenged groups are 80% and 60%,and the incidences of tumor are 80% and 65%,respectively.Neoplasm mostly occurs in heart,liver,spleen,kidney and thymus.The chickens suffering from tumor in two or three tissues count for 65% in the 10-day-old group and 35% in the 21-day-old group,while the chickens with tumor in four or more tissues only count for 5% in the 10-day-old group and 20% in the 21-day-old group.Therefore chickens in the 10-day-old group are sensitive to MDV J-1 strain,and are more sensitive than those in the 21-day-old group.