中文摘要：

为探讨鸡新城疫病毒（NDV）、传染性法氏囊病毒（IBDV）二联灭活疫苗在蛋雏鸡养殖中的实际应用效果进行本试验.用鸡新城疫、传染性法氏囊二联灭活疫苗及传染性法氏囊活疫苗以不同免疫程序免疫7 ～ 14日龄蛋雏鸡,定期监测NDV、IBDV抗体水平,并在雏鸡60日龄时进行攻毒保护试验.结果表明,各二联苗免疫组NDV抗体水平在免疫后14 d即达到NDV血清学最低有效保护价标准,并维持至雏鸡60日龄.免疫后28 d,灭活苗一次性免疫各组IBDV中和抗体水平显著高于活苗两次免疫组,琼扩抗体水平与活苗两次免疫组无明显差异.雏鸡60日龄时攻毒,各免疫组均100％保护,对照组无保护.以上结果说明该二联灭活疫苗可替代IBDV活毒疫苗用于7～14日龄商品雏鸡免疫,免疫期至少为60d.

英文摘要：

In order to investigate the immune effect of the inactivated vaccine against Newcastle disease virus （NDV） and infectious bursal disease virus （IBDV） in chickens, chickens 7 to 14 days were immunized with the combined vaccine using different immunization proce- dures. Serum antibody levels were detected at different time points and the chickens were challenged with a virulent strain at 60 days old. Results indicated that NDV antibody level reached the standard of effective protection at 14 days after vaccination and continued until 60 days old when the experiment was completed. At 28 days post vaccination, neutralizing antibody titer against IBDV was much higher in the inocu- lated chickens with the inactivated vaccine once when compared with the vaccinated chickens with an attenuated vaccine twice. However, there was no significant difference in antibody titer by agar diffusion test between groups of chickens immunized with two kinds of vaccines. The morbidity for immunized groups was zero under virus attack, while that for the control group was up to 100%. All of the above results showed that the attenuated IBDV vaccine could be replaced with NDV-IBDV combined inactivated oil-emulsion vaccine, and the effective period can be up to at least two months with one immunization when the vaccine was used for chickens 7 to 14 days.