为探讨新城疫-传染性法氏囊病二联灭活疫苗(ND-IBD二联灭活苗)对不同日龄商品蛋鸡的免疫效果,选择360只1日龄商品蛋鸡,分别于1、7日龄接种ND-IBD二联灭活苗,对照组接种灭菌生理盐水,分别于21-56日龄,每隔7d采血,分离血清,检测ND和IBD抗体水平,剖检取脾脏与法氏囊观察病变,荧光定量PCR检测免疫因子CD4+、CD8+、IL-6、IFN-β mRNA表达量,并进行攻毒保护试验.结果表明,1、7日龄商品蛋鸡接种ND-IBD二联灭活苗,其ND和IBD的抗体水平均有效提高,且在免疫后可以有效保护IBDV强毒的感染,但7日龄免疫效果更好.免疫因子的mRNA表达量检测结果表明,7日龄接种疫苗的免疫组免疫因子CD4+、CD8+、IL-6、IFN-β的mRNA表达量明显高于对照组1日龄.综上,ND-IBD二联灭活疫苗7日龄免疫商品蛋鸡免疫效果更好.%Immunological effect of combined inoculation of the inactivated vaccines for Newcastleand the infectious bursal diseases (ND-IBD) on egg-laying chickens was investigated.For the study,360 one-day-old commercial chicks were randomly divided into 3 groups.The chicks in one group were immunized immediately with the two vaccines simultaneously,another when they were 7-day-old,and the third group injected with saline solution as control.Levels of ND-IBD antibodies in the serum ofthese chicks were determined,spleen biopsies for disease detection executed,and qPCR on mRNA expressions of CD4+,CD8+,IL-6 and IFN-β performed every 7 days during the period of 21 to 56 d.The results showed that all treated one-or 7-day-old birds had higher antibody levels than control,and could fence off IBD virus infection.The 7-day-old group showed greater immunity against the diseases,and significantly increased mRNA expressions on CD4+,CD8+,IL-6 and IFN-β over control.It was,therefore,concluded that,by combining vaccinations against ND-IBD on 7-day-old egg-laying chicks,a desirable immunological effect on the chickens could be achieved.
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