| Porcine reproductive disorders have always been one of the reasons affecting the economic benefits of pig farms.This study mainly aims to understand the occurrence of pig reproductive diseases in some areas of Hebei,China.By collecting 3022 serum samples,122 diseased materials,and 125 environmental samples from 135 different scale pig farms in Hengshui,Baoding,Qinhuangdao,and Zhangjiakou areas of Hebei Province,To study the antibody levels,pathogen infections,and environmental disinfection of porcine reproductive and respiratory syndrome(PRRS),swine fever(CSF),pseudorabies(PR),and porcine circovirus type 2(PCV-2)diseases,and provide guidance for effective clinical prevention and control.(1)Antibody level:In this experiment,the antibody detection of PRRS serum samples showed that the positive rate of antibody was 84.71%,which did not meet the requirement of 85%.The antibody positive rate of large and medium-sized pig farms is higher than that of small pig farms.The antibody positive rate of medium and large-scale pig farms in 2022 is relatively low.The antibody positive rate of small-scale pig farms from2020 to 2022 was relatively low,with a significant difference compared to large and medium-sized pig farms(P<0.05);There was no significant difference between large-scale pig farms and medium-sized farms(P>0.05).The overall antibody positive rates of CSF and PR were90.41% and 92.43%,respectively,indicating that the pig herd has good antibody immunity.The antibody positive rate of small-scale pig farms in2022 was lower than that at other times.The antibody positive rate of CSF and PR vaccines in large and medium-sized scale pig farms is higher than that in small-scale scale pig farms,but the overall antibody positive rate of PR is in a steady trend from 2020 to 2022.There was no significant difference in the positive rate of CSF antibodies among different scale pig farms(P>0.05);There was a significant difference in the positive rate of PR antibodies between large-scale and small-scale farms(P<0.01),and there was also a significant difference between medium-sized and small-scale farms(P<0.05).There was no significant difference between large-scale and medium-sized farms(P>0.05).The overall positive antibody rate of PCV-2 serum was 78.48%,which did not meet the requirement of 85%.The antibody positive rate of samples was lower than 80% from 2021 to 2022,with the lowest positive rate observed in small-scale pig farms.In general,the positive rate of PRRS antibody in some pig farms in various regions is relatively low,which may be related to the immune response of the PPRS vaccine.The positive rate of PCV-2 antibody in pig farms was low,at only 78.48%.The positive rates of CSF and PR antibodies were not significantly different in different regions,indicating that the two vaccines had better immune effects across different regions.There were significant differences in the positive rates of PCV-2 antibodies between large-scale and small-scale fields,as well as between medium-sized and small-scale fields(P<0.05);There was no significant difference(P>0.05)between large-scale and medium-sized fields.There was no significant difference in antibody positivity rates among different regions(P>0.05).(2)Antigen detection:PRRSV,PRV,and PCV-2 are common in the collection of sows with high fever,fasting and miscarriage.Some cases have CSFV infection.The positive rate of PRRSV antigen detected in suspected samples was 27.05%.The positive rate of CSFV antigen was 3.28%.The positive rate of PRV antigen was 13.11%,while the positive rate of PCV-2 antigen was 51.64%.The detection rate of PRRSV and PCV-2antigens in small-scale pig farms is the highest,showing an increasing trend.The detection rate of antigens in small-scale pig farms is higher than that in large-scale pig farms.(3)Detection of environmental antigen:It can be seen from the environmental samples in the pig farm where suspected samples are collected that PRRSV,CSFV,PRV and PCV-2 are detected on the walls,sewage and feces inside and outside the pig farm.The positive rates of PRRSV and PCV-2 were the highest in different scale pig farms,9.6% and 11.2% respectively.Pathogens were also detected in different samples,especially in sewage and septic tanks,with the highest detection rates of 40% and 56% respectively.The incidence of PPRSV in large-scale pig farms is significantly lower than that in small and medium-sized pig farms,with a significant difference of P<0.05;There was no significant difference in the incidence of PPRSV between small and medium-sized pig farms(P>0.05).Similarly,PRV results are similar to PPRSV,and the incidence of large-scale fields is significantly lower than that of medium and small-scale fields(P<0.05);The incidence rate of medium-sized farms was also significantly lower than that of small-scale farms(P<0.05).CSFV was not detected in large-scale fields,but it was detected to some extent in both small and medium-sized fields,but there was no significant difference between the two(P>0.05).The detection rate of PCV-2 virus was higher in samples from different scale pig farms,but the detection rate of large scale pig farms was significantly lower than that of medium and small scale farms,but there was no significant difference between them(P>0.05).(4)prevention and control technology:At present,there is no good treatment method for these diseases,and daily disinfection and vaccine immunization are often used to prevent the occurrence of diseases.In terms of daily disinfection,the main aisle in the production area is disinfected once a week with potassium persulfate(1:200);Disinfect the enclosure with potassium persulfate(1:200)once every two days;The living area should be thoroughly cleaned and disinfected with glutaraldehyde(1:500)once a week;Disinfect the important areas around the building with 3% caustic soda or bleach once a week;Disinfect the entrance of the pig farm with 3% caustic soda or bleach once a day.In terms of vaccine immunization,corresponding immunization procedures are formulated based on the different positive rates of antibodies in each field and the results of pathogen typing: PRRS vaccines are generally immunized three times a year;The CSF vaccine is generally immunized three times a year;PR adopts a gene deletion vaccine for universal immunization three times a year;PCV-2 can be immunized with prenatal and fetal vaccines for 4 weeks.The results of serological and etiological investigations on the main reproductive disorders of pigs in some areas of Hebei Province,as well as the evaluation of environmental disinfection effects,indicate that PRRS and PCV-2 are currently the main pathogens causing reproductive disorders in pigs.This is related to production management level,biosafety measures,especially vaccine selection and immunization measures.This study provides reference for the control of these diseases and the healthy breeding and high-quality development of live pigs. |
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