Study on Immune Effect of Mycoplasma Synovia Live Vaccine H Strain in Yellow Breeders
To evaluate the immune effect of MS-H strain of live vaccine of Mycoplasma synovia(MS)in yellow-feathered breeders,and to provide clinical reference for the research of infection prevention and control technology of MS in chickens of China.Six batches of yellow feather breeder chickens at 21 and 90 days of age were immunized with live MS vaccine(H strain)at one dose,and serum MS antibody levels were measured regularly.The colonization rate or infection rate of MS-H strain and MS wild strain in the chickens were detected by upper cleft palate swab,and the immunization effect of the vaccine was evaluated.The results showed that:1)The detection of serum MS antibody level found that all chickens showed moderate levels of MS maternal antibody at 1 day of age,with an average titer of 3000 to 5000.With the increase of age,the MS maternal antibody was basically negative at 14,28 and 42 days of age.At 56 days of age,the antibody to MS was gradually changed to positive.2)Two of the six batches were detected the MS wild strain at 42 days of age for the first time,and the positive rate was 100％and 37.5％,respectively.The remaining four batches were firstly detected the MS wild strain at 70,70,84 and 112 days of age,respectively,and the positive rate was below 25％.3)The continuous detection of MS-H strains in chicken flocks showed that MS-H strains were detected in all 6 flocks with l week after immunization,and the colonization rate of most flocks reached the highest at 3-5 weeks after immunization,exceeding 80％,and some flocks reached 100％.The detection rate of MS-H strain remained at 62.5-87.5％until the 52 weeks of age.Hence,the live MS-H strain vaccine was immunized twice in yellow-feathered breeders,and the MS-H strain could colonize well in the flock,lasting up to 52 weeks,and the antibody level of MS was moderate,the infection rate of wild virus was low,and large-scale horizontal transmission could not occur in the flock.In conclusion,the vaccine MS-H strain has a higher colonization rate and a longer maintenance time after immunization of twice in the chicken population,which has a well immune effect and can prevent the infection and horizontal transmission of MS wild strain in the chicken population.
万方数据
维普
