Preliminary Purification Of Avian Leukosis And Chicken Pullorum In A Large-scale Breeder Farm In Hunan Province

Avian leukaemia is an avian infectious disease caused by avian leukaemia virus.The transmission mode of this disease is mainly horizontal and vertical transmission.It is clinically characterized by immunosuppression,growth inhibition and malignant and benign tumors in multiple organs and tissues,resulting in chicken wasting,depressed spirit and death.Avian leukaemia is very common and more and more complicated in the poultry industry in China.In addition,up to now this disease has no vaccine and effective treatment drug,therefore,for the prevention and control of avian leukemia is very difficult,the main prevention and control measures taken is to eliminate positive chicken,chicken flock purification,the establishment of non-avian leukemia infection breeding chicken flock.In this study on a large scale in hunan from 2018 to 2019 such farms in the purification of avian leukosis work and to monitor the effect of purification from the test data shows that in the process of purification of four generation replacement of avian leukosis positive rate continue to reduce,one of the generation of NDV can be isolated from the dead chicken positive rate was 29.75%,white chicken positive rate was 30.22%,the fourth generation 1day age of NDV can be isolated from the dead chicken positive rate was 1.79%,25 weeks of NDV can be isolated from the dead chickens,the positive rate of 1.65%,a white chicken day age of positive rate was 1.79%,25 weeks of white chicken positive rate of 2.12%,It can be seen that the prevalence rate of this disease in breeding farms finally dropped to a very low level,about 2%,indicating that the purification has achieved a significant effect,which provides a reference for the purification of avian leukemia in other chicken farms in China.Chicken pullorosis is caused by chicken pullorum salmonella a bacterial infectious disease,is a very common bacterial infectious disease,the main expression of adult chicken is local,recessive,chronic infection,and the chicken is often shown as acute systemic infection,such as acute sepsis.The morbidity of chick chicken pullorosis and mortality are very high,some chick group mortality can reach 100%,although the mortality of adult chicken is not high,but can become carrier,cause huge economic loss,the harm to poultry industry is very serious.In this study,the purification of pullorum was carried out in a large-scale breeding farm in hunan province from 2018 to 2019 and the purification effect was monitored.Meanwhile,the disease samples were taken for drug sensitivity test,and sensitive drugs were selected for prevention and treatment of the disease.From the test data,the father generation of NDV can be isolated from the dead chicken and chicken enwrapped the total positive rate was 23.16%,after three generations of purification,the positive rate of NDV can be isolated from the dead chicken pullorosis from 21.15% to 5.97%,white chicken positive rate from 25.55% to 6.06%,it can be seen in three generations of purification replace pullorosis positive rate continue to reduce,in the process of purification achieved significant effect.A series of purification measures of this kind of chicken farm have played a good demonstration role in the prevention and treatment of pullorum in other chicken farms throughout the country.