鸡毒支原体活疫苗（F36株）两种免疫方案效果比较

Immune Effects Comparison of Live Mycoplasma gallisepticum Vaccine（Strain F36）By Two Application Methods

关键词:  鸡毒支原体  活疫苗  保护率  定植率  全群免疫  同居免疫  免疫效果

Key words:  Mycoplasma gallisepticum  attenuated vaccine  protection rate  colonization rate  herd immunity  cohabitation immunity  immune effect

摘要:

为评价鸡毒支原体活疫苗（F36株）两种免疫方案的效果，以活菌浓度3×106CCU／羽份的F36株鸡毒支原体活疫苗点眼免疫2日龄SPF鸡，采用全部鸡群分别免疫1羽份1/4羽份、1/10羽份和1/40羽份，以及仅有1/2、1/4、1/6 比例的鸡免疫 1羽份、其余鸡同居饲养两种方案，全群免疫或同居免疫30d后攻毒，攻毒14d后剖检，观察气囊病变，各组免疫后30d内每周测定F36株定植率。 另外，对商品鸡群也采用两种方案免疫鸡毒支原体活疫苗，分为全群免疫（ 剂量为1/2羽份）和同居免疫（1/2鸡群免疫1羽份，1/2鸡群同居饲养）,分别测定免疫后不同时间 F36株鸡毒支原体的定植率，并统计生产数据。 结果显示，SPF鸡全群免疫鸡毒支原体（F36株）活疫苗1/10羽份可以达到 60%以上的保护；同居免疫时，1/2鸡群免疫 1羽份疫苗，另外1/2鸡群同居，其全群保护率低于 60%，随着同居鸡比例的增加，其保护率逐渐下降。 商品鸡全群免疫1/2羽份鸡毒支原体F36株活疫苗组的定植率、平均出栏体重优于1/2鸡群免疫1羽份疫苗、另外1/2同居鸡群组。 结果表明，对鸡群进行鸡毒支原体活疫苗（F36株）免疫时，全群免疫方案优于同居免疫方案。

Abstract:

In order to evaluate the immune effect of different application methods of attenuated Mycoplasma gallisepticum vaccine ( MG F36) , the study involved ocular immunization of 2-day-old SPF chickens with a live MG vaccine F36 ( bacterial concentration: 3 × 106 CCU/dose ) . Two immunization schemes were implemented : (1) All chickens received different dosage regimens - 1 dose , 1/4 dose , 1/10 dose and 1/40 dose , respectively; ( 2 ) Partial immunization regimen - only 1/2 , 1/4 or 1/6 of the flock received 1 dose vaccine , with the remaining chickens being co - housed for contact exposure. After immunization or cohabitation , all chickens were challenged 30 days later, and the pathological changes of the air sac were observed 14 days after the challenge. In addition , the colonization rate of F36 strains were measured every week within 30 days after immunization. In addition , merchandise chickens were vaccinated with live MG vaccine F36 by two application methods , group in which all chickens were immunized with 1/2 dose respectively , together with group in which only 1/2 flock was immunized with 1 dose and another 1/2 flock was raised together, were involved , the colonization rate of MG F36 strain was measured at different times , and production data were compared. The results showed that SPF chicken subgroup of 1/10 immunizing dose could achieve more than 60% protection rate by whole group immunization , and in the group of cohabitation immunity , if the proportion of immune chickens was reduced , subgroup in which 1/2 flock was immuned with 1 dose and another 1/2 flock was raised together, the whole population had a total protection rate of less than 60% , as the proportion of cohabiting chickens increased , their protection rate decreased gradually. In the ordinary chicken flocks , the colonization rate and average body weight were better in group which was immunized with 1/2 dose live MG vaccine F36 than that group in which 1/2 flock was immunized with 1 dose and another 1/2 flock was raised together. The results showed that the immune effect of herd immunity was better than that of cohabitation immunity when the live MG vaccine F36 was used in chickens.