法氏囊活性肽对鸡传染性法氏囊病弱毒疫苗免疫效果的影响

将不同剂量的法氏囊活性肽 (BS)冻干粉与鸡传染性法氏囊病 (IBD)弱毒疫苗混合 ,对 2 1日龄SPF鸡滴鼻点眼 ,另设免疫对照组和生理盐水对照组 ,于免疫后 7d、10d、14d、2 1d、2 8d、45d、6 0d、75d和 90d采血 ,测定AGP抗体效价 ,并于免疫后 7、14、2 1、2 8d ,每组剖杀 2只 ,计算试验组囊指数与空白对照组囊指数之比 (BBIX) ,免疫后 30d用IBD JS株攻毒。结果表明 :免疫后 7d ,0 48mgBS IBD弱毒苗组AGP抗体阳性率为 5 2 9% ,比免疫对照组高 2 5 % ,BBIX数值也稍大 ;免疫后 45d抗体水平达到高峰时 ,0 96mgBS IBD弱毒苗组的抗体效价比免疫对照组高2个滴度 ,BBIX数值也稍大于免疫对照组。 30d后攻毒 ,各免疫组的攻毒保护率均为 10 0 %。整个试验期间 ,1 92mgBS IBD弱毒苗组的AGP抗体效价及BBIX数值与免疫对照组相比差异不显著。结果表明 :BS在增强机体免疫应答、提高对法氏囊的保护及损伤后的修复作用方面与其剂量有一定的关系。

Effects of Bursin on Immunoreaction of Attenuated Vaccine of Infectious Bursal Disease in Chicken

SPF chickens with twenty one years old were inoculated with attenuated vaccine of infectious bursal disease (IBD) mixed with different dosages of lyophilized bursin by the eye drop method.The immunization control group and blank control group were inoculated with IBDV live vaccine and normal saline respectively.The agar gel precipitation(AGP) antibody titers against IBDV live vaccine were detected at 7 d,10 d,14 d,21 d,28 d,45 d,60 d,75 d and 90 d postvaccination.At 7 d,10 d,14 d,21 d,28 d postvaccination,two chickens in every group were killed and the BBIX(bursal index in experimental groups/bursal index in blank control group)was worked out.Three chickens in every group were challenged with IBDV JS strain at the 30th day postvaccination.The results showed that the positive ratio of AGP antibody against IBDV in the group of 0 48 mg bursin was 52 9% and 25 0% higher than that in immunization control group 7 d after vaccination.During the high peak period of antibody,the AGP antibody titer in the group of 0 96 mg bursin IBD attenuated vaccine were hgiher than that in immunization control group about 2 titers averagely . The effect of 0 48 mg bursin was better than immunization control group at 7 d postvaccination , but BBIX of the 0 96 mg bursin IBD attenuat ed vaccine group was larger than that of immunization control group and blank control group at 14 d postvaccination.At the 30th day postvaccination,the protective ratios of four immunization groups were 100%.During the whole experiment,there was no evident difference between the 1 92 mg bursin IBD attenuated vaccine group and immunization control group about the antibody titers and BBIX.These results suggest that bursin can not only shorten the time of antibody against IBDV induced by attenuated vaccine of IBD,but also alleviate the lesion of IBD attenuated vaccine to bursa of fabricius and promote the repairation of the lesion,and these effects of bursin have a relation to its dosage.