为探讨湖北某试验猪场猪群PRRS减毒活疫苗的免疫效果,选择HP-PRRS弱毒疫苗(JXA1-R株)对20头35日龄仔猪进行初步免疫试验,4周后采血进行PRRS抗体检测; 另采集未免疫疫苗的20、30、60、70、120日龄阶段猪只血样194份,免疫疫苗的基础母猪群血样265份和配种前后备猪血样65份,分析其血清PRRS抗体阳性率、S/P均值和CV值. 结果显示,20头35日龄仔猪免疫疫苗后4周抗体阳性率达85%,S/P均值和CV值分别为1.55和30%,初步表明疫苗免疫效力良好;未免疫疫苗的猪只在20~60日龄时抗体值随母源抗体逐步下降,在60日龄时达到最低为33%,70~120日龄时抗体值由85%上升到96%,说明此生长阶段已感染PRRSV;全部母猪群和后备猪抗体阳性率分别为87%和92%,S/P值>2.5的比例为9.1%,表明疫苗总体免疫稳定,并判断该场为PRRSV感染阳性稳定场.通过试验研究,旨在为该场科学防控PRRS提供临床依据.%In order to investigate the immune effects of attenuated PRRS live vaccine in a pig farm in Hubei, 20 piglets of 35-day-old were selected to get vaccination by hp-PRRS attenuated vaccine (JXA1-R strain). After four weeks the blood antibody against PRRS were tested. Simultaneously, 194 samples of unvaccinated piglets at 20, 30, 60, 70, 120 days stage,265 samples of breeding sows and 65 samples of gilts were collected for serum antibody positive rate of PRRS, S/P mean and CV values. The results showed that the antibody-positive rate of the 20 piglets was 85% after four weeks, the S/P mean and CV values were 1.55 and 30%, respectively. It indicted that the vaccine had good efficacy. The antibody value of the unvaccinated piglets at 20-60 days of age gradually declined with the maternal antibody and reached a minimum of 33%at 60 days of age. 70-120 days the antibody positive rates were ranged from 85% to 96%, which indicated that this stage had been infected with PRRSV. The antibody positive rates of breeding sows and gilts were 87% and 92%, respectively. The ratio of S/P value more than 2.5 was 9.1%, which indicated that the vaccination was overall stable and the farm was deter-mined positive stable farm infected PRRSV. The experiment was aimed at provide a clinical reference for scientific PRRS prevention and control.
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