A Study Of Classical Swine Fever Purifying Scheme On Large-scale Pig Farms

In order to study the classical swine fever purification scheme in large-scale pig farms, this paper takes the pigs in a large-scale pig farm located in Tianjin as sample, studying the detection and safety disposal on poisoned positive breeding pigs, the methods to improve the CSF antibody, and the immunization program for CSF in large-scale pig farms. In the part of detection and safety disposal, the enzyme-linked immunosorbent assay(ELISA) and reverse transcriptase polymerase chain reaction(RT-PCR) are adopted to detect the CSF in one hundred and fifty pigs. Meanwhile the poisoned pigs are disposed safely by processing machine. In the second part, the ELISA antibody detection kits are adopted to detect the relationship between maternal antibody level and the day, taking sixty different piglets as samples. Also the differences of antibody level among pigsties are detected. The effective methods to improve the CSF antibody level are proposed based on the regular conclusion in experiments. In the stage of virus immunization, several effective suggestions and programs are proposed, which provide effective theoretical foundation and practical reference for formulation of CSF immunization program. The main results are as follows:1. In the sixty abortion and stillbirth pig samples, ELISA detects four samples are positive antibody level and positive rate is 6.7%, while RT-PCR detects three samples and positive rate is 5%.2. In the fifty bleed samples of abortion sows, both ELISA and RT-PCR detect six positive antibody samples and positive rate is 12%.3. In the forty dead pig samples, ELISA detects four positive antibody samples and positive rate is 10%, while RT-PCR detects three samples and positive rate is 7.5%.4. In the detection of poisoned positive pigs, the positive rate detected by RT-PCR is lower than ELISA, which is caused mainly by the highly genetic maximums of CSF and the antibodies in different genes may have cross reactions.5. The safety dispose conducted by organic waste disposition machine largely decreases the positive rate and has a high speed and security coefficient.6. Newborn piglets have a low antibody level when lactation is short, while after one week, the antibody level is relatively high and will decrease as time goes on.7. The antibody level in piglets is kept mainly by breast feeding, which can be used to predict the antibody level in piglets.8. The proposed CSF immunization program can be a reference basis for the foundation of common bio-security management system in large-scale farms.