| Influenza is an epidemic disease caused by orthomyxoviridae virus that can infect humans and many other animals.According to records,influenza is distributed throughout the world,and widespread in many animal populations and humans.The Ministry of Agriculture of China had included highly pathogenic avian influenza in the national animal disease compulsory immunization plan,and clearly requires that the herd immunity of highly pathogenic avian influenza should be maintained at more than 90% per year,of which the immunity density of livestock and poultry should be100%.At the same time,the qualification rate of immune antibodies should be maintained at more than 70% year-round.In order to understand the immune effect of H5-subtype highly pathogenic avian influenza in broiler and laying hen breeding populations in Yongchuan area and whether the qualified rate of immune protests meets national requirements,the breeding populations of large-scale broiler and laying hen farms in Yongchuan area were deliberately selected.Random sampling was performed for the avian influenza pathogen detection and the H5-subtype highly pathogenic avian influenza immune antibody qualification rate.There are many poultry farms in Yongchuan District,Chongqing,including breeding poultry(chickens),broilers,laying hens,waterfowl and other breeding poultry.Among them,the annual stock of broilers and laying hens is 3 million to 4million birds,which is an important economy.Income sources of industry and farmers.In order to better understand the current immune status and effect of H5-subtype highly pathogenic avian influenza in the whole region,so as to achieve the nationally required "prevention-oriented,combination of maintenance and prevention" policy.The H5-subtype highly pathogenic avian influenza pathogen detection and the detection and analysis of the H5 immune antibody qualification rate were specifically conducted on the breeding population of large-scale broiler and laying hen farms in the Yongchuan area to understand the large-scale chicken farms in the Yongchuan area.Whether the antibody level meets the national standard for antibodies.It is also a test of the effectiveness of our grass-roots immunization and anti-epidemic work,demonstrating whether the immunization and anti-epidemic work that we are currently taking can enhances the resistance of poultry(broilers and laying hens)inthe Yongchuan district,thereby reducing the scale Infection and incidence of H5-subtype highly pathogenic avian influenza in chicken farms.The main content of this experiment is all the 35 farms in Yongchuan district which have reached the breeding scale(according to Chongqing ’s livestock and poultry breeding scale standards,the laying hens farm should have more than 600 birds and the broilers farm should have more than 1200 birds)were sampled and monitored.The average annual total number of farms was 622,220 birds and the time span was from 2017 to 2019.A total of 100 pharyngeal swabs and tissue samples of unknown disease deaths are randomly taken from each farm every quarter,and the PCR method is used to monitor for avian influenza pathogen infection.After testing for 17-19 years,The 1200 samples taken were all negative and no signs of avian influenza virus infection were found.At the same time,200-300 serum samples are randomly taken every month,and the immune antibody concentration and the qualified rate of immune antibodies in the breeding population are detected by a hemagglutination test and a hemagglutination inhibition test.Through testing,the qualified rate of overall immune antibodies in large-scale chicken farms in Yongchuan area in 2017 was 83.09%,the qualified rate in 2018 was 87.20%,and the qualified rate of overall immune antibodies in 2019 was 91.52%.All meet national requirements.In addition,through horizontal comparison analysis,the pass rate of antibody in laying hen farms is generally better than that in broiler farms.Through visits to understand and demonstrate,this reason is mainly due to the long hen breeding cycle,and the effect of individual immunity is more stable than that of broilers with short breeding cycles,Better results.This shows that the qualified rate of immune antibodies in laying hen farms has been maintained at a high level,and the levels of immune antibodies in broiler farms have fluctuated according to certain rules over time.The above tests show that the immune effect of H5 subtype highly pathogenic avian influenza in large-scale chicken farms in Yongchuan area from 2017 to 2019 has reached the national standard.According to the experimental results of avian influenza etiology,there is no evidence in large-scale chicken farms.Bird flu virus infection.Large-scale farms(the number of laying hens in stock is above 6000 birds,and the number of broiler hens in stock is above 12,000 birds)have a high level ofimmune antibody concentration and pass rate.Between 6000 birds and broiler stocks between 1,200 and 12,000),the overall immune antibody concentration and pass rate are slightly lower than those of large-scale farms,but all meet the national 70%standard. |
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