The Monitoring Of CSFV And PRRSV Antibody Levels, The Immune Program Formulation For CSF And PRRS

Classical swine fever (CSF), one of the most important animal infectious diseases, has been seriously endanger the global pig industry. In China, classical swine fever is also one of the most severe epidemic of pigs, and is classified as class I animal disease. Porcine reproductive and respiratory syndrome (PRRS) is also an important infectious disease which seriously harm to the pig industry development. Especially in recent years, disease caused by PRRS virus mutant often outbreak in China and all over the world. Vaccination is one of the most important measures to prevent and control classical swine fever and PRRS. Antibody monitoring is the most efficient, direct method, to assess the immune effects. Pathogen detection can help us keep abreast of the prevalence of the epidemic. Antibody monitoring combined pathogen detection help to assess the effect of vaccination, adjust the immune process in a timely manner.In this study, we use indirect hemagglutination test for detection of classical swine fever antibody levels.we tested555swine sera collected from2007to2012. Results of the tests showed there were553samples, whose HCV antibody hemagglutination titer is1:16or above, accounting for99.6%of the total serum. For most of the serum, HCV antibody hemagglutination titer are1:64,1:128or1:256, accounted for22.3%,39.3%and34.8%. The results shown that CSF ultra pre-immunity can improve the swine fever antibody level. The suckling piglets swine fever antibody positive rate increased from98.9%to100%. And the HCV Antibody level become more neat. The hemagglutination titer is more focused on1:64,1:128and1:256, but generally speaking, the change was not significant.Detected18piglets tissue samples, one of them was CSFV positive, but the piglet did not show clinical symptoms, indicating it maybe latent infection or just vaccine virus. We have collected12boar semens for detecting swine fever pathogen, result showed that one of them was HCV positive. However, the HC positive sample was collected within one month after the swine fever vaccine. It may be just vaccine virus, because result we re-examination for classical swine fever pathogen two months later was negative.352pig serum was collected for testing the PRRS antibody levels,201of them were positive, the positive rate was57.1%. The positive rate for sows, suckling piglets and nursery pigs was respectively59.4%,46.8%and64.8%.The report shows that in August2008and April2009, the PRRSV antibody positive rates were36.8%and35.7%.However at this time there were no PRRS immunization, indicating that part of the herds is infected wild PRRS virus or have been infected wild virus before. From April2010, swine PRRSV antibody levels increased significantly after using classic PRRSV strain Live vaccine. The report shows that in June2010and August2012, the PRRSV antibody positive rates were62.8%and62.2%. But does not reach the level of70%, may not be able to protect herds. The report shows that in June2010and August2012, the PRRSV antibody levels of sows,which have not immunized PRRSV vaccine, reached57.7%and60%. It indicate that sow herd Carry wild PRRS virus is widespread.26samples were collected for detecting PRRS pathogen detection, of which13were visceral tissues and13were boar semens.11of13visceral tissues were PRRSV mutants positive, and2of13boar semens were PRRSV mutants positive, indicating that the herd were infected with PRRSV variant in recent years.Boars swine fever immunization centralized immunization in April and October each year to be able to obtain a good immune effect, four doses of vaccine per pig. Backup sow inoculated with swine fever live vaccine4doses per head before breeding and multiparous sows inoculated with swine fever live vaccine4doses per head7days before weaning can get a good immune effect. For piglets CSF immune, routine immunization recommended while stable, the first immune at20days for2doses per head, and Strengthen the immune at55-60days for2doses per head. When the production of unstable, we can try to take CSF ultra pre-immunity or CSF ultra pre-immunity combined with routine immunization. The key to PRRS vaccine is to select the vaccine, which has high quality and high homology with the area epidemic wild strain. And as well as monitoring the PRRSV antibody titer, timely adjustment of the PRRS vaccine immunization programs can get a good immune protective effect.