【作者】 周庆华；

【导师】 余兴龙；

【作者基本信息】 湖南农业大学 ， 兽医， 2010， 硕士

【摘要】 由猪繁殖与呼吸障碍综合征病毒(PRRSV)引起的猪繁殖与呼吸障碍综合征(PRRS)又称蓝耳病,在我国猪养殖业的病史已久,主要以引起母猪繁殖障碍及影响小猪呼吸系统综合征为主要特点,传播之快,波及之广,严重影响我国猪养殖业的健康发展。1995年PPRS初次全面爆发于全国,目前PRRSV变种引起的“高热病”正在全国蔓延,相比普通PRRS危害更为严重。本论文通过酶联免疫吸附试验(ELISA)监测2005年4月、11月,2006年4月、11月,2007年4月、11月,2008年4月、11月,2009年4月、11月湖南某规模猪场的种猪(母猪、后备母猪、公猪)及不同阶段商品猪的PRRSV抗体水平,结果显示此规模猪场种猪群、商品猪群的PRRSV血清抗体水平消长规律与猪群中蓝耳病的流行情况以及猪群的生产指标之间有一定的关系。这种关系主要表现在猪群中PRRSV平均抗体S/P值与变异系数基本呈负相关的关系,而当变异系数越大,平均S/P值越低的时候,猪群爆发蓝耳病的风险越大；当变异系数越小,平均S/P值越大的时候,猪群越稳定,生产指标越好。在2007年6月,猪群爆发蓝耳病时,为了使猪群集中感染PRRSV,缩短疫病持续的时间,对种猪群进行了人工感染实验。结果表明人工感染实验之后猪群可以获得高水平的PRRSV抗体水平,且变异系数小,猪群生产稳定。但PRRSV仍然在猪群中存在,主要是在仔猪母源抗体水平消失之后能够再次感染,但是对其影响较小,只表现轻微的症状就会恢复正常。但是人工感染之后的这种效果只保持了将近2年。2年之后种猪群抗体水平以及仔猪的母源抗体水平都显著下降,且变异系数变大,猪群又重新出现蓝耳病疫情,这种情况与人工感染实验之前的2年情况相似。这也进一步说明了猪群PRRSV抗体水平的整齐度以及抗体水平的高低对防止猪群爆发蓝耳病的重要性。本实验还发现后备母猪的引进能够直接导致PRRSV抗体水平的波动,给整个猪群造成威胁,所以猪场应了解引种对于猪场所需承担的风险,以制定关于引种的相关保障措施。通过抗体检测,了解商品仔猪抗体消长的规律,了解PRRSV在该猪场的感染环节,通过分别对种猪、商品猪的血清抗体检测,预测猪群中爆发蓝耳病的风险,为PRRS的防控提供有效信息,能更有效的进行针对性的防疫工作。更多还原

【Abstract】 Porcine reproductive and respiratory syndrome viruses(PRRSV) can cause to porcine reproductive and respiratory syndrome(PRRS), other called disease of blue ears. It induces reproductive disorder of sows and impact respiratory system of piglets, which have long history with the infection in my country. It is to spead quickly, involve widely, and hardly break away the pig cultivation from the healthy development road. PRRS was breaked overall out for the first time in our coutry,but now "high fever sick "is spreading to entrie county, contract to PRRS more harmful.This study use ELISA serological method to monitor the PRRSV antibody of the boars(sows, replacement gilt, boars) and the commercial pigs of different age in the pig farm from 2005.04 to 2009.11 every half a year.The result shows that the PRRSV antibody level of the boars and the commercial pigs growth and decline actuality concerns with the clinical disease and symptom of pigs, and that it understands the PRRSV antibody of swinery fluctutate impact the antibody level and growth and decline regular pattern.In 2007.6, the farm break out PRRS, artificial infection was carry out to make the swinery infect PRRSV intensively and shorten the dease time cause by PRRSV.The result show that the swinery can gain a high level antibodies against PRRSV and the coefficient of variation about the swinery was very low.The performance of the swinery was stable and superiority. Although PRRSV was still in the farm which can be see from infection of the piglets lost the maternal antibody of PRRSV, the harm to the piglet was not severity. The effectiveness of artificial infection was last nearly two years. Two years later, the farm break out PRRSV again, the situation came back to the time before artificial infection.These indicated the importance of the high level antibodies of PRRSV and the regularity of antibodies to resist the PRRS.Controlling growth and decline regular pattern of piglets and recognizing PRRSV infection link, it can be more effective to direct to remove virus. This experiment also express that fluctuation of PRRSV antibody level was caused by replacement gilts, threating swinety. It should comprehend the risk to assume the responsibility, and enact the protection of introduction. Through analysising the antibody level of entire pigs, prevention and control plan was instituted.更多还原