The Research On Variations Of Antibody Against PRRS,CSF In Large-scale Breeding Farms And Its Application In Healthy Process Management

Porcine reproductive and respiratory syndrome, also called swine blue-ear disease, is a deadly and worldwide spread viral disease caused by Porcine reproductive and respiratory virus(PRRSV) which is characterized by reproductive syndrome in sows and respiratory syndrome in piglets. It causes great economics losses to porcine industry each year and is listed to be reported as B class infectious disease by OIE. Classify swine fever is a highly contagious infectious disease caused by classify swine fever virus and listed to be one of the 16 kinds of legal diseases of A class by OIE. Both of two diseases is the second class animal disease of 16 kinds of animal disease in the national project. PRRS and CSF are immune suppression diseases. There are many issues about these two diseases such as elimination, prevention and immunization. Combining with the farm performance,this study is going to build an effective model of swine health management in breeding farm according with herd immunity study.The purpose of this study is to set up the baseline of PRRS serological evaluation for PRRS status. The regular serological monitoring plan for PRRS had been carried out in different large breeding farm to get the detail test data of swine herd such as antibody titer(S/P value), dispersion from 2010 to 2013. The farm’s PRRS status would be defined according to its production. After analysis of the serological result of stable farm, the baseline of antibody titer and dispersion had been summarized as below:(1)the average antibody titer for breeder is between 1.0 and 2.0(S/P value);(2)the dispersion is between 50 and 70. Both of them are the important index to evaluate the PRRS vaccination and risk.The purpose for this study is to set up the baseline of Classical swine fever(CSF)serological evaluation. The monitoring protocol had been carried out in two breeding farms with good performance from 2011 to 2014. After finishing these trials, the regulation of Classical swine fever antibody titer and dispersion of a stable and good performance had been summarized as below:(1)the average antibody titer(Block%) should be above50%,(2)the average dispersion(CV value) should be below 25.Both of them are the important index to evaluate the Classical swine fever vaccination and risk.Based on the baseline model of PRRS and CSF serological evaluation, swine herd health management protocol had been carried out in a big breeding farm in order to build the healthy management model. The core of the model is bio-security system, process management and serological monitoring. The first step should be focused on process management:(1)two sites or three sites production;(2)gilts and sows acclimatization: the serological monitoring of PRRS Antibody titer should be frequent during the PRRS acclimatization. The second step should build a strict bio-security system to restrict the virus circulation in the farm as possible. The third step is to set up the disease risk prevention system: the regular serological monitoring of mainly virus disease especially for PRRS and CSF should be carried out to get the data, then evaluation of disease risk would be forecasted according the baseline. In this study, the farm had been improved obviously after applying the healthy management protocol for one year. The performance had been improved such as farrowing rate, parity, born alive, mortality. With the performance improving, the economic was considerable such as the cost decrease. The farm had maintain the good performance for two years by keeping applying the healthy management protocol. It’s a feasible protocol to strengthen the farm management and provide a way for disease elimination.There are too many PRRS vaccine in the market and it’s difficult to choose. Also there are high possibility for virus recombination by vaccinating different strain in the same farm,even the virus maybe stronger than before. It’s important to set up a rapid diagnosis method to identify different PRRS strains, such as PCR. But the previous RT-PCR can’t the variant strain. In this study, HRM-PCR had been built to identify the strains based on the technical platform of HRM analysis especially for GDr180,TJM-F92 and JXA1-R strains.