洛阳地区奶牛流产主要病原的检测与分析

发布时间：2018-04-30 03:01

本文选题：奶牛 + 流产　；参考：《河南科技大学》2015年硕士论文

【摘要】：近年来,奶牛流产呈上升趋势,部分地区奶牛流产率高达20%,给奶牛养殖业造成了严重的经济损失。检测引起奶牛流产主要病原,分析奶牛流产原因,对预防控制奶牛流产具有重要的意义。通过走访调查洛阳地区各个奶牛场(小区)发现,部分奶牛场流产率高达20%左右。其中在第2-4胎流产的母牛数最多,流产率高达17.22%~25.18%;流产母牛多集中在4、6、7、10月份,流产数占流产总数的52.24%(256/490),流产率高达18.56%~23.67%;奶牛在妊娠的各个阶段都会流产,但多发生在奶牛妊娠110~170 d之间,流产头数占总数的47.14%(231/490)。为检测洛阳地区引起奶牛流产的主要病原,于2013年7月至2015年3月,收集该地区奶牛场(小区)共42头新鲜流产胎牛,及其母体的血液、阴道分泌物和鼻腔分泌物,计为42例样本,采用PCR或RT-PCR方法进行新孢子虫、弓形虫、胎儿三毛滴虫、布氏杆菌、牛传染性鼻气管炎病毒和牛病毒性腹泻病毒6种常见流产的病原体核酸检测。结果表明,被检样本总感染率为42.9%(18/42),其中新孢子虫感染率最高,为40.5%(17/42);IBRV次之,为11.9%(5/42);胎儿三毛滴虫、布氏杆菌、弓形虫和BVDV感染率分别为2.4%、2.4%、2.4%和0。14.3%(6/42)的被检样本存在混合感染,其中以新孢子虫+IBRV混合感染为主(50%,3/6)。结合被检流产奶牛的临床特征及饲养管理等因素,推断新孢子虫是导致该地区奶牛流产的最主要病原。为了进一步了解该地区新孢子虫的感染情况,采集流产母牛或有过流产史的母牛血清,进行新孢子虫抗体间接ELISA的检测。结果表明,该地区新孢子虫的血清抗体阳性率平均为44.44%(88/198);规模化养殖场新孢子虫抗体阳性率为47.06%高于散养户41.67%;流产奶牛新孢子虫抗体阳性率为58.97%高于正常奶牛40.88%;第二胎次母牛新孢子虫抗体阳性率最高为53.12%;3岁的母牛新孢子虫抗体阳性率最高为48.84%。此结果也证实了洛阳地区奶牛流产多是由新孢子虫引起的。犬是新孢子虫的终末宿主,养殖场(小区)内犬的存在与新孢子虫居高不下的感染率有密切的联系。本试验从奶牛流产率较高的奶牛场(小区)采集犬的新鲜粪便,采用饱和蔗糖漂浮法检测犬粪便中新孢子虫卵囊,对疑似新孢子虫未孢子化的卵囊进行PCR鉴定。结果,采集的12份新鲜粪便中,检出3例新孢子虫,结果证实了犬与新孢子虫感染率较高有密切的联系。本研究将为该地区有效防控奶牛流产提供科学依据。
[Abstract]:In recent years, the abortion rate of dairy cows is increasing, and the abortion rate of dairy cows in some areas is as high as 20%, which has caused serious economic losses to the dairy cattle breeding industry. It is of great significance to detect the main causes of abortion in dairy cows and analyze the causes of abortion in dairy cows. Through the investigation of the dairy farms in Luoyang area, it was found that the abortion rate of some dairy farms was about 20%. Among them, the number of cows aborted in the 2nd to 4th trimester was the highest, the abortion rate was as high as 17.220.18; the aborted cows were concentrated in October, 52.2425 / 490 of the total number of miscarriages, and the abortion rate was as high as 18.5656 / 23.67.The cows had miscarriages at all stages of pregnancy. But most of them occurred between 110 days and 170 days of pregnancy, and the number of miscarriages accounted for 47.14% of the total. From July 2013 to March 2015, 42 fresh aborted fetal cows, their blood, vaginal secretions and nasal secretions were collected from dairy farms in Luoyang area, from July 2013 to March 2015. PCR or RT-PCR methods were used to detect the nucleic acid of six common miscarriages of neosporidium, Toxoplasma gondii, Trichomonas foetus, Brucella, bovine infectious rhinotracheitis virus and bovine viral diarrhea virus. The results showed that the total infection rate of the tested samples was 42.9% / 42%, and the infection rate of neosporidium was the highest, with 40.5% / 42% IBRV, followed by 11.910 / 42%; the infection rates of trichomonas, Brucella, Toxoplasma gondii and BVDV were 2.42.42.4% and 0.14.3% 6 / 42, respectively. Among them, the mixed infection of neosporidium IBRV was mainly 50% of the total. Combined with the clinical characteristics and feeding management of aborted cows, it was inferred that neosporidium was the main pathogen leading to the abortion of dairy cows in this area. In order to further understand the situation of neosporidium infection in this area, the sera of aborted cows or cows with history of abortion were collected to detect the indirect ELISA of neosporidium antibodies. The results show that The positive rate of neosporidium antibody was 44.4488 / 88 / 898% in this area, 47.06% higher than 41.67% in large scale breeding farm, 58.97% higher than 40.88% in abortive cow, 40.88% in second born cow, 47.06% in large scale farm, 58.97% in aborted cow and 40.88% in normal cow. The highest positive rate of neosporidium antibody was 53.12 and the highest positive rate of neosporidium antibody was 48.84 in 3 year old cows. The results also confirmed that the abortion of dairy cows in Luoyang area was mostly caused by neosporidium. Canine is the terminal host of neosporidium. The presence of dogs in farm (plot) is closely related to the high infection rate of neosporidium. In this study, the fresh feces of dogs were collected from dairy farms with high delivery rate. The oocysts of neosporidium were detected by sucrose saturation floating method, and the unsporulated oocysts suspected of neosporidium were identified by PCR. The results showed that 3 cases of neosporidium were detected in 12 samples of fresh feces. The results showed that the infection rate of neosporidium was higher in dogs. This study will provide scientific basis for the effective prevention and control of dairy cow abortion in this area.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.23

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