Investigation On Epidemiology Of Porcine Reproduction And Respiratory Syndrome In Shan Dong

The porcine reproductive and respiratory syndrome(PRRS) is one of the causative disease which has risen humorous economic loss on swine industry.It's pathogeny is the porcine reproductive and respiratory syndrome virus (PRRSV).The disease is characterized by reproductive troubles such as abortions farrowing or weak piglets, preweaning pislets pneum onia mortality and mortality in sows.To investigate the prevalence station,it's distribution,occurrence,spread approach inShandong Province, so we research the epidemiology of Porcine Reproduction and Respiratory Syndrome in Shan Dong.This syudy designed the outer pair of primers F1 R1, a 400bp products was obtained and the inner pair of primers F2 R2,a 170bp was amplified to establish a nested PCR assay, were used to detect PRRSV PRV PCV-2 CSFV and negative control.The results showed that except for PRRSV, other detect results are negative;RNA was extracted and diluted 10-1~10-4.A visible objictive strip can be amplified still.This indicated that the established nested PCR assay has the virtues of stronger speciation,higher sensitivity and well stability.The epidemiological investigation was carried out by questionnaire in Shan Dong Province.The investigation results showed that immunity hogpen still.The PRRS often occur in the Spring and Winter,and in July and Augest of each year.The breed type of disease swine is small scale breed hogpen and individual breed. Clinical of PRRS characterized only by sow reproductive troubles is 30%;Piglets respiratory symptom is 50%;sow reproductive problems-Piglets respiratory symptom is 30%;preweaning syndrome is 40%;other clinical symptom is 10%.The samples were detected,the resultshowed that the sample had the positive;the positive ratio is 12.5%~100%,the average positive ratio 34.4%.This indicated that the PRRS has been a important disease which damages to swine industry.