| Avian infectious bronchitis(IB)is an infectious disease caused by avian infectious bronchitis virus(IBV).It is an acute and highly contagious infectious disease.Chickens are susceptible at all stages.The disease mainly affects the respiratory system,urogenital system and digestive system of chickens,causing huge economic losses to the chicken industry.Vaccination is considered to be the most effective way to prevent and control infectious bronchitis in chickens.However,due to the large number of IBV serotypes and prone to mutation,the cross-protection between serotypes is poor,which brings about the prevention and control of infectious bronchitis in chickens.Difficult.In order to understand the law of antibody growth and decline and the immunization situation of a poultry company in Xinjiang over the years,three different immunization programs were developed based on the antibody level and the previously used immunization procedures,and antibody monitoring was performed to analyze a set of better ones.Immunization program.Improve the selected immunization program,compare the ELISA monitoring data and some production performance after immunization with the original program,and get a more suitable immunization program for the region,providing a basis for the adjustment of Xinjiang chicken infectious bronchitis immunization program.The research content and results of this experiment are as follows:Method:(1)Choose 3 Ephedra chicken breeders from a large-scale company in Xinjiang(named as Breeder Farm 1,2,and 3)and 4 Huang Mayu commercial chicken farms(named as Commercial Chicken Farm 1,2,and 3),four).Investigate the immune status of infectious bronchitis in the experimental chicken farm,and use the IBV ELISA test kit to detect the law of antibody growth and decline during 2016-2018.(2)According to the immunization situation,the stability of the chicken group and the ELISA test data,a plan A was designed for IBV immunization: 7-day and 50-day-old use Xinyizhi(Newcastle disease,infectious bronchitis combined live vaccine(La Sota strain + QXL87 strain);Plan B: 1 day and 7 days old and use(ND+IB+H9+IBD)-K and Xinyizhi respectively for immunization.Use Xinyizhi once at 50 days of age.Plan C : 7-day and 50-day-old use three different immunization programs of live chicken infectious bronchitis vaccine(H120 strain)and chicken infectious bronchitis live vaccine(H52 strain),(3)in Hutubi and Changji,Xinjiang Select a breeder farm and a commercial chicken farm in each region to test the antibody situation produced by the immunization program.Finally,the program is improved(1 day old and 7 day old respectively use(ND+IB+H9+IBD)-K),New Yizhi for immunization,strengthen once at 45 days old)According to ELISA data and part of the production performance,compare with the original program to get a better immunization program.Results:(1)The antibody positive rate of the three breeder farms under investigation gradually tended to 100% with the increase of age,the dispersion gradually decreased,and the antibody level was relatively neat.The positive rate basically reached 100% after 20 weeks of age or 26 weeks of age,and the dispersion gradually decreased.However,the antibody titer of breeder farm three before 2019 was relatively large.At 26 days of age,commercial chickenfarms 1,2,and 4 have generally low antibody positive rates and low dispersion.However,the50-day and 70-day-old positive rates are 100%,and the dispersion is low.The overall antibody titer of commercial chicken farm 3 is relatively large,and the dispersion is relatively high.(2)The overall situation of antibody production in the B program is more stable than the other two vaccine programs,but the positive rate of the B program in the 50-day age group failed to reach 100%.The dispersion is also slightly higher.The overall situation of antibody production in Plan A was better than that in Plan C,but the pens of the breeder farm showed a greater degree of dispersion at 50 days of age,and all pens had antibody titers greater than15,000.The data tested in the C program suggest that the immune program of this program has poor effect,high dispersion,and high antibody titers,suggesting that the program has problems such as weak protection.(3)A comparison between the improved immunization procedure and the original one found that the improved only had an antibody positive rate of less than 100% at 25 days of age,but the dispersion was higher at 50 days of age,and the antibody titer value was at Below 13500.In contrast,the original immunization regimen had a high antibody dispersion.The antibody positive rate was less than 85% at 25 days of age,and the antibody titer was relatively large.At 50 days and 70 days,there were titers above 16000 and The phenomenon of more than 17,000.In terms of production performance,the production data of the improved immunization program enclosure is significantly better than the original immunization program enclosure.The improved immunization program has an average higher egg production rate of 3.48% than the original immunization program;an average lower egg production rate of 0.68%;an average lower rate of broken eggs 0.42%,but the rate of soft eggs is relatively low.To sum up: the risk of IBV wild virus infection will gradually decrease with age.At the same time,breeder farm 3 and commercial chicken farm 3 may have wild virus infection or have been infected with wild virus before 2019.According to the new immunization program and the selection of vaccine strains,it can be concluded that the vaccine strains of QXL87 and M41 strains should be preferentially selected and used for immunization in this area.At the same time,they should be used at the age of 1 day,7 days and 50 days,respectively(ND+IB+H9+IBD)-K,Xinyizhi and Xinyizhi are better immunization programs.Finally,it shows that the adjusted immunization program can provide good production performance and is more suitable for experimental areas. |
