Study On The Investigation Of The Causes Of Reproductive Disorders In Pigs In Shandong Province And The Integrated Control Measures Against These Diseases

Disturbance of reproductive failure in sows and boars are the main diseases in the swine production. It shows that abortion, premature delivery, fetal death, feeble body, featus anomalies, mummy body and even not pubescence for a long time. These diseases are of high infectiosity. Once the sows suffered from these diseases, it will lead to the infection of the whole pigs.Shandong province is a big district that is rich in pig production. But the infection of diseases of reproductive failure in recent years affected the scale of cultivation and the economic returns. Extension of reproductive failure diseases made many small factories bankrupt. Some big farms paid a large amount of money to treat these diseases, but it was difficult to clear up these diseases. According to the statistics of the livestock and veterinary office in Shandong province from the epidemic prevention stations, we can see that epidemic area of infectious disease located in the middle, west and south area in Shandong province. The main popular diseases are pseudorabies (PR), porcine reproductive and respiratory syndrome (PRRS) and swine plague of reproductive failure type. For the above, we do the following three-part study:In order to identify the causative agent of reproductive diseases in sows in Shandong province, six big farms in the middle, south and west district in Shandong province were chosen to be the experimental materials. In two years, eighty-nine cases were collected and some information was noted during the experiment. The collected cases were done by cultivation of bacterial and biochemistry experiment, detection of enzyme linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR). It showed that pseudorabies and porcine reproductive and respiratory syndrome are the main diseases of reproductive failure in Shandong province. The swine plague of reproductive failure type is only nine of the thirty-nine cases. Its proportion is very small. Based on the result, pseudorabies and porcine reproductive and respiratory syndrome in the infected farms always combined each other, which will make the situation worse. The percentage of porcine reproductive and respiratory syndrome (PRRS) and pseudorabies is 77.5% (69/89) and 72% (64/89), respectively. Meanwhile, the percentage of combined of PRRS and PR is 52%, which leads to the deterioration of the diseases. To improve the speed of diagnosis, accuracy and specificity during the diagnosis of sows'reproductive failure diseases, the method of multiple-PCR was established in our lab. Design of primer, amplification of PCR and location in the four viruses, that is, pestivirus suis, virus of pseudorabies, porcine reproductive and respiratory syndrome virus and porcine minute virus, were applied in the experiment. According to the result, the multiple-PCR method is of good specificity and fast speed during the diagnosis of these diseases. The detection of clinical cases further proved the accuracy and specificity of multiple-PCR method.On account of the characteristic of sow reproductive failure diseases in Shandong province, how to control the prevalence of pseudorabies and porcine reproductive and respiratory syndrome in the brood sows is of a great advantage for the development of pig production in Shandong province. Therefore, one farm (Taierzhuang farm) was chosen to be the experimental material, where the pseudorabies is very serious. Seven hundred heads of sows and boars were chosen to be the material. The pseudorabies immunization and detection of antibody were applied to the subject. It shows that this immunization is safe to the conceived sows, which can improve the conception rate and survival rate of the young pigs. Also, the reproduction function of boars was significantly improved. Finally, the averge level of antibody increased with the the augmentation of the conceptus age of sows.The pseudorabies immunization and detection of antibody were applied to the sows and boars. Immunization was used to control and clear up the pseudorabies, which will provide the theatrical cause for the integrate control of porcine reproductive failure diseases. Furthermore, we will obtain the relevant measures to control other diseases from this experiment. In a word, forcible immunization and integrate control measures can better improve the prevalence of porcine reproductive failure in Shandong province.