| The poultry breeding industry in Chashan Town,Dongguan City is developed.It is located in the core geographical position of the megacities in the Pearl River Delta.After the reform and opening up,the poultry breeding industry in Chashan Town began to flourish and gradually developed into one of a meat-based food supply bases in the surrounding cities of the Pearl River Delta.In particular,the town’s characteristic white pigeon breeding industry,at the peak of the period,the total inventory of the breeding pigeons in Chashan Town once exceeded 2 million.In recent years,due to environmental protection policies and other reasons,the total amount of poultry farming in Chashan Town has declined,especially the proportion of broiler farming has been greatly reduced.By the end of 2016,the number of breeding pigeons in Chashan Town still exceeded 800,000 pigeons.The annual number of pigeons sold to the Pearl River Delta urban agglomeration was 7 million.The other 12 farmers’ markets in Chashan Town also transferred more than 1million broilers from the field every year.It can be seen that the annual flow of poultry in and out of Chashan Town is relatively large.Avian influenza and Newcastle disease are the two most serious diseases affecting the poultry industry.They have been defined by the World Organisation for Animal Health(OIE)as Class A infectious diseases.It is currently occurring in many countries and regions in the world,causing serious economic losses to farmers.In recent years,it has been reported that people infected with avian influenza are a serious threat to human health and public health.Newcastle disease is often accompanied by the outbreak of avian influenza.Therefore,it is of vital importance to investigate the prevention and control of avian influenza and Newcastle disease in Chashan Town.Through the evolutionary analysis of four H9N2 avian influenza viruses isolated from Chashan Town in 2017,the results showed that the HA gene of E46 strain in four H9N2 subtype avian influenza viruses isolated from Guangdong in 2017 originated from the G1 branch,while the rest The H9N2 strains are all derived from the Y280 branch,and the E46 HA gene is highly homologous to the H9N2 strain sequence uploaded in the database from2016 to 2017.The HA genes of F110,E55 and 16344 strains are all in the same evolutionary branch as the strains prevalent in China from 2015 to 2017,indicating that these strains may be derived from local strains.The NA gene of the E46 strain is derived from the evolutionary branch of G1,and the remaining strains are derived from the Y280 evolutionary branch.Therefore,the H9N2 E46 strain derived from Guangdong is a G1-derived strain,while the F110,E55,and 16344 strains are Y280-derived strains.This study summarized the immune antibody passing rate and pathogen positive rate of avian influenza and Newcastle disease in live poultry of three Chashan township monitoring sites(Chashan Agricultural Market,Chashan Farm,and Chashan Sanatorium)from 2014 to 2017 to assessment the prevention and control of avian influenza and Newcastle disease in Chashan Town.1437 serum samples were collected at Chashan Agricultural Market for H5 avian influenza antibody detection,984 serum samples for Newcastle disease antibody detection,1128 swabs for avian influenza detection,and 444 swabs for Newcastle disease surveillance.A total of 1074 sera were collected on a large-scale farm for detection of avian influenza antibodies,1140 serums were used for Newcastle disease antibody detection,1674 swabs were used to detect avian influenza,and834 swabs were used to detect Newcastle disease.Among the free-range households,420 serums were collected for detection of avian influenza antibodies,459 serums for Newcastle disease antibody testing,816 swabs for avian influenza detection,and 207 swabs for Newcastle disease surveillance.The survey results showed that the average pass rate of avian influenza antibody in Chashan agricultural market was 53.35%,the average positive rate of H9 subtype avian influenza virus was 69.94%,the average positive rate of general avian influenza virus was65.69%,and the average pass rate of Newcastle disease antibody was 53.66%.The average pass rate of avian influenza antibody in Chashan farm was 43.22%,the average positive rate of H9 avian influenza virus was 19.85%,the average positive rate of general avian influenza virus was 33.09%,and the average pass rate of Newcastle disease antibody average pass rate remained at 76.84%.The average qualified rate of avian influenza antibodies in households in Chashan sank households was maintained at 58.57%,the average positive rate of H9 avian influenza virus was 19.85%,the average positive rate of general avian influenza virus was 33.09%,and the average qualified rate of Newcastle disease antibodies remained at 63.40%.Newcastle disease pathogens were detected in only100 free-range households in Chashan in 2017.The positive rate was 9.26%.The pass rate of avian influenza and Newcastle disease antibodies in Chashan Townwas lower than 70% in 2014-2017,and the positive rate of avian influenza remained high except in 2017.The positive rate of Newcastle disease and avian influenza in scale farms in Chashan Town is not high,but the situation of year-on-year decline in avian influenza antibody levels must be given sufficient attention.The eligible rate of antibodies against avian influenza and Newcastle disease in households with free-range breeding showed an upward trend.The positive rate of avian influenza was lower except in 2016. |
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