Infection Survey And Immune Effect Evaluation Of Classical Swine Fever In Part Of Large Scale Pig Farm In Guangxi

Classical swine fever (CSF) is the enemy that harm for swine industry in our country. Epidemic characteristics produced apparent change in strong immune pressure and various environmental changes under the influence of CSF in recent years. It is difficult to clinical diagnosis and prevention because CSF and other diseases caused by mixed infection that lead to pathological changes and clinical symptoms become more and more complex. The kind of pig CSFV sustained virus infection is the most headaches, it not only causes the serious barriers to reproduction, but also caused the death of newborn piglets of sows and immune tolerance, and virus infection has become one of the main causes in the spread of CSFV. Therefore, it is cann’t wait to carry out a herd CSFV has been purified.To tie in with the projects sponsored by the Ministry of Agriculture and the Ministry of Science and Technology on infection and immune effect evaluation of CSF in large-scale pig farms. The goal is to analysis the survey to pig swine fever and other major diseases clinical symptoms, pathological changes, virus infection and genetic variation analysis through to the Guangxi some large scale pig farm, and to further grasp the resent swine fever clinical and pathologic changes of the situation, at last to kind of CSFV infection situation. To formulate the control purification measures of CSF for the further. The main results are as follows:1. Through the portion of the487samples detected by pig, rate of CSF detection was11.91%; wherein, typical of atypical hog cholera swine fever accounted for18.18%, others accounted for81.82%; in the case of mixed infection by CSFV and PRRSV mixed infection accounted for21.21%.2.33head of CSF in anatomic pathology results show, at present on clinical lesions reductes to6cases, atypical CSF in majority. Atypical lesions in epiglottic cartilage surface pinpoint bleeding (17/27), the ileocecal valve local ulcer (16/27), myocardial petechial hemorrhage (11/27), renal pale, surface has the tip of the bleeding point (10/27), hyperemia bladder, bladder mucosa and mucosal bleeding spots (8/27) accounted for the majority, CSF the typical lesions of splenic marginal infarct (5/27), the ileocecal valve button necrosis rare (4/27). 3.15strains of CSFV E2gene sequencing and Genbank landing is completed. Through comparing Guangxi epidemic strains that discover their nucleotide homology is75.8%-100%; deduced amino acid homology is77.6%-100%, mainly for the gene I group and II group.2.1subsets virus and all strains were D25G variation widely appear in various subsets of strain that regularity of the variation in amino acids which compared with SHIMEN and HCLV strains.4. CSFV antibody detection in Guangxi7different dimensions pig farm of1814pig serum, found that antibodies general pass rate only83.13%(1508/1814), antibody levels are different in different scale field pig, and the antibody diversity is high, the average of diversity is up to35.48%, pig antibody level is too difference, which may lead to occurred in the presence of CSF.