雏鸡抗新城疫母源抗体消长规律的研究

对600余只新城疫疫苗免疫母鸡的子代和非免疫子代雏鸡做五批新城疫母源HI抗体滴度的检查,结果出现三种不同动态曲线:(1)出壳后母源HI抗体滴度最高(Log_2 3.45),以后伴随日龄的增长,滴度直线下降。(2)出壳后母源HI抗体滴度较低(Log_2 0.2),到9日龄出现高峰,以后下降。(3)出壳后血清内有一定滴度(Log_2 2.6),,并逐渐下降,3日后开始回升,至9日龄达最高峰,以后随日龄增加,抗体滴度衰减。HI母源抗体保持日数,最短是19日龄消失,最长28日龄消失。第一次雏鸡接种应根据血清HI抗体滴度而定。

A STUDY ON THE PATTERNS OF INCREASE AND DECREASE IN YOUNG CHICKS' MATERNAL ANTIBODIES AGAINST NEWCASTLE DISEASE

In this study, more than 600 chicks whose parents were either immunized or non-immunized were used and their maternal HI antibody tilers were examined in five groups. The results of the examination can be expressed in three different dynamic curves. The first curve indicated that the highest titer was Log_2 3.45 shown by the chicks just after hatching, descending linearly along with chicks' growth. The second curve told us that the newly-hatched chicks' tilers were relatively lower (Log_2 0.2) and that the highest titer did not appear until the age of nineth day, and after this age it came down again. The third curve showed that the serum from the newly-hatched chicks contained certain amount of antibody (with a titer of Log_2 2.6),and after this the antibody tiler dropped gradually until the third day after hatching, from then on it began to rise, the highest tiler in the third curve was found in the chicks at age of nine days, and afterwards dropping along with age. The durations of the HI maternal antibody among the chicks, the shortest being 19 days and the longest 28 days after hatching. Thus, the time when the first vaccination should be given to the young chicks must be determined according to the HI maternal antibody liters in their serum.