| With the continuous development of the sheep farming industry in the Hexi Corridor,the scale of this industry has been expanding because of huge market for sheep meat.However,the introduction of large number of foreign breeds of sheep and the frequent trading of foreign live sheep have brought great pressure on the prevention and control of sheep disease in Hexi.Foot-and-mouth disease,peste des petits ruminants,brucellosis,and sheep pox are the main infectious diseases which are seriously threatening large-scale sheep farms now.Foot-and-mouth disease and peste des petits ruminants are epidemic diseases that require mandatory immunization from the Ministry of Agriculture of China.Brucellosis is a zoonotic infectious disease.Sheep pox has a great impact on the quality of sheep skin,hair,cashmere,and causes more serious income loss to the sheep farmers.To this end,the large-scale sheep farm industry in Hexi was chosen as the research object,and serological investigation methods were used to investigate the epidemic diseases including foot-and-mouth disease,brucellosis,peste des petits ruminants,and sheep pox,so as to timely explore the diseases of sheep.The level of immune antibodies and the trend of change are most significant for the prevention and control of these four diseases and for healthy development of the sheep industry.For sampling large-scale sheep farms in Hexi,4 cities and 19 counties were randomly selected,from which 876 sheep farms were investigated and a total of 13,933 serum samples collected.For the detection and evaluation of the groups,immune group A(immunized sheep),group B(Brucellosis,sheep pox unimmunized sheep),representing Brucellosis and sheep pox positive infection rate and group C(foot-and-mouth disease,peste des petits ruminants unimmunized sheep group(sick sheep,pregnant sheep,etc.)representing the foot-and-mouth disease and peste des petits ruminants positive infection group were detected.The immune antibody levels and latent infection of the four diseases of sheep were statistically analyzed,and provided basic information for the prevention and control of the four diseases in large-scale sheep farms in Hexi.1.From 2015 to 2018,a total of 13,933 serum samples were collected in four cities of Hexi.According to the annual survey,,a total of 1,437 samples were collected in 2015,1,832 collected in 2016,4,893 collected in 2017,and 5,771 collected in 2018;According to the sample source,a total of 9,406 samples were from group A,4,220 samples from group B,and 307 samples from group C;According to the different farming scale sources,3,759 samples were collected from 50-200 large-scale sheep farms,6,022 samples from 200-500 large-scale sheep farms,and 4,152 samples from 500 or more large-scale sheep farms.From the large-scale sheep farms,876 samples were collected,324 from 50 to 200 large-scale sheep farms,390 from 200-500 large-scale sheep farms,and 162 from large-scale sheep farms with more than 500 sheep.2.In group A,the individual pass rate and group pass rate of foot-and-mouth disease immune antibodies in the 4 years were 78.44% and 78.2%,respectively.The individual pass rate and group pass rate of peste des petits ruminants' immune antibody were 79.76% and 80.02%,respectively.The individual pass rate and group pass rate of sheep pox immune antibody were 64.4% and 62.9%,respectively and finally,the individual pass rate and group pass rate of brucellosis immune antibody were 58.96% and 50.68%,respectively.In group B,the positive individual and group rate of antibody against sheep pox infection were 2.96% and 10.96%,respectively,the positive individual rate and group rate of antibody against brucellosis were 3.79% and 12.67%,respectively.In group C,The positive individual and group rate of antibody against foot-and-mouth disease were 13.03% and 3.88%,respectively.The positive individual and group rate rate of antibody against small ruminant infection were 4.89% and 1.71%,respectively.3.Through analysis of the number of positive sites of the four infectious diseases,it was found that the detection rate of suspected foot-and-mouth disease positive infection decreased from 14.75% to 1.32%,from the larger-scale sheep farms to the smaller-scale sheep farms,from the pastoral area to the agricultural area;the detection rate of suspected Peste des Petits Ruminants infection decreased from 11.48% to 0.26%;The detection rate of suspected sheep pox positive infection decreased from 31.15% to 7.67%,from pastoral area to semi-agricultural and semi-pastoral area to agricultural area,and the source of sheep farm included three different types of sheep farms.Hidden infections are more serious;although the detection rate of suspected brucellosis positive infection decreased from 27.78% to 10.32%,the hidden infections in agricultural and pastoral areas were also serious,the risk of spread was large,and the prevention and control situation was very serious.4.Through selection of demonstration farms,the work was carry out with integrated prevention and control technology for sheep foot-and-mouth disease,sheep pox,the peste des petits ruminants,and brucellosis,and a technical model for prevention and control was develop for the above-mentioned diseases suitable for large-scale farms.Investigation,technology integration research,normative immunization program formulation and implementation,serum antibody titer monitoring,and other works played an important role in the demonstration.Before the technical teacher's work,the immune antibodies in the demonstration field were tested.The immune antibodies of foot-and-mouth disease,peste des petits ruminants,sheep pox,and brucellosis were 70.14%,70.7%,65.63% and 35.94%,respectively.Through application of integrated technology in demonstration farms,the immune antibody was detected every 6 months.In 2018 and 2019,the immunization rate of foot-and-mouth disease was 78.87% and 85%,the immune antibody yield of the sheep ruminant was 84.23% and 85.79%,the eligibility rates of immune antibodies were 80.56% and 81.84%,and the average pass rates of immune antibodies against the brucellosis were 61.92% and 62.45%,respectively.The pass rate of foot-and-mouth disease,peste des petits ruminants disease,and sheep pox immune antibody exceeded the requirements of the Ministry of Agriculture,but the immune antibody against brucellosis of sheep did not meet the requirements,and this may have a certain relationship with the immune effect of the disease vaccine itself. |
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