Serological Investigation And Analysis Of Four Major Diseases In Cattle Farms In Hunan Province

The cattle breeding in Hunan Province is in a period of large-scale transformation.Multiple pathogenic infections occur in cattles,which threatens the cattle breeding.In order to understand the current status of the cattle breeding industry in Hunan Province,a questionnaire survey was conducted in this thesis.In addition,770 bovine serum samples from 74 cattle farms were collected from 14 cities and prefectures in Hunan Province during October to December 2019,and the infection and prevalence of four epidemic diseases including bovine viral diarrhea(BVD),infectious bovine rhinotracheitis(IBR),bovine tuberculosis,and bovine paratuberculosis were investigted.Meanwhile,450 of 770 samples were subjected to serological surveys for mycobacterium bovis(M.bovis)and mycobacterium avium subsp paratuberculosis(MAP).The results from the questionnaire survey showed that the proportion of small and medium-sized cattle farms(with a stock of less than 200 cattle)are the main cattle-breeding scale,accounting for 87.32%,and only 12.68% of those with a breeding scale greater than 200 cattles,and the proportion of beef cattle was 92.96%.There exist three feeding patterns as proportions ofcaptive,free-range,captive and free-range combination,with proportions of46.48%,11.27% and 42.25%,respectively.The source of cattle is mainly self-breeding,accounting for 46.48%.Cattles from most of farms(98.59%)were immunized with FMD vaccine,while bovine ephemeral fever,bovine pasteurellosis and nthrax vaccines onlyvaccinated in part of the farms,accounted for 7.04%,7.04% and 2.82%,respectively.The results show that the cattle breeding-scale in Hunan province is mainly small and medium-sized,and the economic type is mainly to raise beef cattle.The breeding method is mainly captive,captive and free range.The source of cattle is mainly self-breeding and self-breeding.Mostly cattles is immunized against FMDV vaccine.Serological survey results show that serological positive rates are high for BVDV and IBRV antibodies;thefarm antibody positive rates were 51.35% and 74.32%,and individual antibody positive rate were 23.54% and 45.45%,respectively.Meanwhile,M.bovis and MAP antibodies were positive in samples from parts of hte cities and prefectures,and their field positive rates were 13.64% and 22.73%,respectively,and the individual antibody positive rates were 3.11% and 4.67%.The results showed that BVDV and IBRV infection are common in the detected cattle farms,and M.bovis and MAP infection were also threats to cattles in regions.Further statistical analysis was performed based on the serological results of the four detected diseases in 41 medium and large-scale cattle farms.The results showed that the positive farm antibody rate to epidemic diseases was as high as 88.64%(36/41),and the individual antibody positive rate against multiple epidemic diseases reached 54.54%(20/36).The results showed that the multiple infection of the four diseases was serious in medium and large-scale cattle farms.The breeding management level,disease prevention and control technologies need to be improved.The present study can provide epidemiological data reference in Hunan Province,which is helpful to prevent and control the related diseases in the cattle breeding.