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1.
妊娠相关糖蛋白(PAG)在奶牛早期妊娠诊断上的应用现状   总被引:1,自引:0,他引:1  
妊娠相关糖蛋白(pregnancy associated glycoproteins,PAG)是反刍动物妊娠后外周血液出现的特异性蛋白,在妊娠过程中发挥着重要的作用。目前,在生产上通过检测PAG在血清中浓度能够进行奶牛的妊娠诊断。作者综述了PAG的发现、分离纯化及其在奶牛体内的代谢水平和近年奶牛早期妊娠诊断上的应用情况。  相似文献   

2.
选取273头荷斯坦奶牛,在人工输精后的28d和75d分别采用牛妊娠相关糖蛋白(PAG)ELISA和直肠检查的方法进行妊娠诊断,比较PAG ELISA和直肠检查法的结果,旨在评价PAG ELISA对配种28d的奶牛进行早期妊娠诊断的准确性。结果表明,PAG ELISA法妊娠诊断的敏感性、特异性、阳性预测值、阴性预测值和准确性分别为100%、75.5%、86.5%、100%和90.5%,与75d直肠检查结果相同,可用于母牛的早期妊娠诊断。妊娠诊断对于母牛保胎、分群管理及提高繁殖效率等具有非常重要的意义。  相似文献   

3.
为了研究妊娠相关糖蛋白(PAG)检测试剂盒在人工授精(AI)后28~32 d奶牛早期妊娠诊断上的应用效果,试验采集49头AI后28~32 d奶牛血液样品,分离血清并应用PAG检测试剂盒进行检测;采血当天利用兽用B型超声诊断仪(B超)进行妊娠检查,并于AI后第35天用B超复检。结果表明:AI后28~32 d,PAG检测试剂盒检测奶牛早期妊娠的灵敏度、特异性、阳性预测值、阴性预测值、准确性分别为92.0%、95.8%、95.8%、92.0%、93.9%,与B超检测方法结果的一致性(Kappa值)为0.632。说明PAG检测试剂盒可以高效应用于奶牛的早期妊娠诊断中。  相似文献   

4.
奶牛配种后,及时且准确了解奶牛的妊娠状况至关重要.奶牛早期妊娠诊断可显著缩短平均育种间隔,提高奶牛养殖效率.随着早期妊娠诊断技术不断发展,检测牛妊娠相关糖蛋白(PAG)逐渐被人们重视,尤其是酶联免疫吸附试验(ELISA)得到更多的开发与利用.目前国外已有PAGELISA牛妊娠检测试剂盒用于检测怀孕早期PAGs,该方法快...  相似文献   

5.
简单、准确的早期妊娠诊断,是减少空怀,提升母畜繁殖力、提高养殖场经济效益的重要手段。直肠触诊、B超检查、孕酮检测等传统妊娠诊断方法,虽然为养殖生产提供了重要技术支撑,但还未实现母牛配后最早检测,部分养殖场还难以满足较高的技术要求或实验室条件。胚胎滋养层细胞分泌的妊娠相关蛋白(PAGs)是奶牛妊娠过程中的重要蛋白,其血液含量变化规律为妊娠诊断方法研发提供了新思路。本文简要概述了现有妊娠诊断方法,详细论述PAGs诊断方法发展历程,展望未来妊娠诊断技术发展方向,使其在“早”、“准”、“简便性”上取得重要进展,并为相关研究提供了重要参考。  相似文献   

6.
《中国兽医学报》2017,(7):1408-1413
妊娠相关糖蛋白(pregnancy-associated glycoprotein,PAG)是一类动物妊娠后胎盘产生的特异性蛋白质,是判断妊娠的重要信号物质。为了获得绵羊妊娠相关糖蛋白PAG3的制备方法,以期通过检测绵羊体内的妊娠相关糖蛋白的含量来进行早期妊娠诊断。本试验通过原核表达生物工程合成的方法,将绵羊妊娠相关糖蛋白编码基因序列插入到表达载体pET20b中,利用原核表达转化大肠杆菌获得了融合His标签的目的蛋白PAG3。经过超声波裂解、His标签亲和层析的方法纯化获得了妊娠相关糖蛋白PAG3。  相似文献   

7.
酶免疫分析法诊断家畜妊娠研究进展   总被引:1,自引:0,他引:1  
母畜配种(或授精)后不久,必须进行妊娠诊断,以便加强怀孕母畜的饲养管理,保证顺利分娩或对未孕母畜及时补配,减少空怀。生产实践中广泛应用的直肠检查等方法,尽管简单易行,不需特殊设备,但检出时间长,判断结果不够准确。随着集约化畜牧业的发展,生产上迫切需要一种简单易行的早期妊娠诊断方法。酶免疫分析法(EnzymeImmunoassay,简称EIA)是由Dray等(1975)建立起来的一种早期妊娠诊断方法,以抗原抗体结合为基础,以酶促反应作为检测信号,将抗原抗体反应的特异性和酶的高效催化反应的灵敏性有机地结合起来,测量母畜体液…  相似文献   

8.
本试验采用半定量RT-PCR的方法,检测和分析了牛PAG基因mRNA在妊娠牛及空怀牛血液中的表达规律。结果发现,PAG基因mRNA在妊娠21d的母牛及空怀牛血液中都有表达,而妊娠牛表达量显著高于空怀牛(P〈005)。这说明配种后21d奶牛血液中PAG基因的表达量可以作为奶牛早期妊娠诊断的依据。  相似文献   

9.
奶牛早期妊娠诊断一直以来是奶牛养殖亟待解决的问题,特别是近年来奶牛养殖业飞速发展,奶牛早期妊娠诊断更加影响着奶牛的发展。家畜早期妊娠诊断方法研究历史悠久,从早期观察配种后母畜周期发情停止和使用最为直接的直肠检查法,到20世纪50年代开始至今相继发展起来的妊娠诊断方法很多。本文仅将在生产中具有实际应用和发展前景的早期妊娠诊断技术应用现状综述如下。  相似文献   

10.
《畜牧与兽医》2014,(8):100-102
近20年来,家畜早期妊娠诊断技术向着诊断时间早、速度快、方法简单、经济的方向发展;对妊娠或未孕母畜的饲养管理、临床检查具有重大意义;能有效地提高母畜的繁殖效率和减少经济损失。本文对近年来应用于家畜早期妊娠诊断的临床诊断法、实验室诊断法及新的诊断方法作一简单介绍。  相似文献   

11.
The plasma profile of pregnancy‐associated glycoprotein (PAG) and its relationship with fetal number were studied in 14 North Moroccan goats using a semi‐heterologous radioimmunoassay (RIA). Peripheral blood was collected every day during the first month of pregnancy, afterward the blood samples were collected trice a week. The PAG were first detected at day 20 of pregnancy, their levels increase to week 8 of gestation then decrease slightly until parturition. Statistical differences between goats carrying one or two foetuses are observed from week 5 of pregnancy until parturition. Factorial Discriminant Analysis provides mathematical models for the discrimination between the litter size using the PAG level and the week of pregnancy. Using only one blood sample per week, high sensitivity, specificity and overall accuracy (74%, 88% and 81%) were obtained using these models. It is concluded that the PAG RIA is an effective tool for early diagnosis of pregnancy and for discrimination between the litter sizes in North Moroccan goats.  相似文献   

12.
Pregnancy‐associated glycoproteins (PAGs) are produced by mono‐ and binucleate trophoblast cells in the ruminant placenta. PAG appears in maternal blood and, from approximately 4 weeks after fertilization onward, may serve as a reliable means of diagnosing pregnancy. A range of factors are said to affect plasma PAG concentrations, such as number and sex of foetus, mass of calf and placenta, level of milk production and genetic constitution. In this study, PAG pregnancy profiles of a dual‐purpose (Simmental) and two beef breeds (Uckermark and Aubrac) are compared with the profile of the specialized dairy breed Holstein–Friesian. Holstein–Friesian cows were sampled weekly; the levels of the other breeds were presented at 3‐week intervals. The overall significant breed difference (p = 0.013) was founded on deviations during the initial 3 weeks of pregnancy and from 23 weeks onward. During the period critical for the detection of pregnancy, between four and 22 weeks, agreement between PAG levels of various breeds was close (p > 0.05). No significant effect of body mass of cow or calf (relative to mass of dam) was detected. These findings imply that the PAG pregnancy test may be executed uniformly irrespective of breed or type of cow, affirming the suitability of the test as a valuable asset for the cattle industry.  相似文献   

13.
[目的]分析PAPPA(妊娠相关血浆蛋白A)和PAG(妊娠相关糖蛋白)mRNA在不同妊娠时期奶牛外周血的表达规律.[方法]提取奶牛空怀期和妊娠30 d、60 d、90 d、150 d和240 d血浆中游离RNA,RT-PCR扩增PAPPA和PAG的基因,分析其在妊娠期的相对表达水平,并研究其表达规律.[结果]PAG基因...  相似文献   

14.
It has been shown in several mammalian species that during pregnancy, trophoblast cells express a range of pregnancy-associated glycoproteins (PAG). The presence of PAG in the maternal serum of cows may serve as an indicator of pregnancy from day 28 after AI onward. The present study addresses (1) conversion of an existing PAG-RIA to a competitive double antibody ELISA using a polyclonal anti-bPAG-IgG and an anti-rabbit-IgG raised in sheep for coating and (2) application of newly established ELISA to test its suitability for pregnancy detection by measuring PAG in serum or milk. The intraassay coefficients of variation (CV) for the PAG-ELISA were 2–14% for serum and 10–12% for milk; the corresponding interassay CVs were 8–22% and 12–22%, respectively. Pregnancy-associated glycoprotein profiles established in milk and serum of 12 pregnant cows showed a characteristic pattern with measurable amounts from approximately day 20 onwards in serum and from day 60 onwards in milk. In a field trial, serum PAG was determined in 397 cows sampled between 20 and 50 days after insemination. The outcome was that, pregnancy could reliably be diagnosed from day 28 onwards in serum and from day 150 onwards in milk. In conclusion, it may be stated that the established ELISA provides an efficient and reliable means of pregnancy diagnosis that will, in our judgement, gain in popularity with cattle breeding. The ELISA proved to be an adequate and efficient way of measuring PAG in maternal serum or milk and will be a useful means of pregnancy detection in cows.  相似文献   

15.
The objective of the present study was to compare two commercially available blood-based pregnancy tests, namely BioPRYN, an ELISA for pregnancy-specific protein B (PSPB), and an ELISA for pregnancy-associated glycoprotein (PAG), for early pregnancy diagnosis in dairy cattle using transrectal ultrasonography as a gold standard. Transrectal ultrasonography was conducted 26-58 days after artificial insemination (AI) in 197 cattle from 19 farms. Concurrently, a blood sample was collected for determination of serum PSPB and PAG. Transrectal palpation was performed approximately 120 days after AI to verify that pregnancy was maintained. For PSPB and PAG, there were no significant differences (P>0.05) in sensitivity (98.0 and 97.8%), specificity (97.1 and 91.2%), positive predictive values (99.3 and 97.8%), negative predictive values (91.9 and 91.2%) and accuracy (97.8 and 96.4%). In conclusion, the two blood pregnancy assays were equally efficacious and were highly accurate (based on transrectal ultrasonography as the gold standard).  相似文献   

16.
This study was designed to establish possible factors affecting plasma pregnancy-associated glycoprotein (PAG) concentrations during early pregnancy in high producing dairy cows with live fetuses. Blood samples were obtained on days 35, 42, 49, 56 and 63 of gestation from 80 lactating cows in two herds carrying live fetuses. Radioimmunoassay systems were used to determine PAG (RIA-497 and RIA-706) and progesterone concentrations. We evaluated the effects on PAG concentrations of herd, lactation number, sire of fetus, day of gestation, fetus number, plasma progesterone and milk production at each time point established, along with possible paired interactions. Mean milk production per cow approached 41kg during the study period. PAG concentrations were not affected by herd, lactation number or plasma progesterone concentration. Significant positive effects on PAG concentrations were shown by the gestation day, and the interaction between day of gestation and twin pregnancy. Significant differences between bulls and a significant negative correlation between milk production and PAG values on day 63 of pregnancy were also detected. Proportions of blood samples showing undetectable PAG levels and false negative diagnoses throughout the study period were significantly higher (P<0.001) using the RIA-497 system (2.5% and 5.3%, respectively) compared to RIA-706 (0% and 0.8%, respectively). Our findings suggest that PAG concentrations during the early fetal period are related to the day of gestation, milk production, number of fetuses and sire of fetus in high producing dairy cows. Under our working conditions, the RIA-706 method was better at detecting plasma PAG molecules than the RIA-497 system.  相似文献   

17.
The present study sought to determine: (i) the effects of Neospora caninum infection and twin pregnancy on plasma pregnancy‐associated glycoprotein‐2 (PAG‐2) concentrations throughout pregnancy and (ii) whether plasma PAG‐2 concentrations could predict abortion in N. caninum‐infected cows. The study was performed on a commercial Holstein‐Friesian dairy herd in northeastern Spain and the final data included those recorded in 53 non‐aborting and 19 aborting animals. Blood samples were collected immediately before pregnancy diagnosis (on Days 40, 90, 120, 150, 180 and 210 post‐insemination) in non‐aborting cows or until the time of abortion detection in aborting cows. General lineal models (GLM) repeated measures anova revealed the different behaviour of PAG‐1 and PAG‐2, and significant effects of Neospora seropositivity, cool season and twin pregnancy on plasma PAG‐2 concentrations throughout gestation (between‐subject effects). In addition, based on the odds ratios, the likelihood of abortion increased in Neospora‐seropositive cows (by a factor of 7.0) compared to seronegative animals and decreased in cows with a high plasma PAG‐2 concentration (>4.5 ng/ml) on Day 120 of pregnancy (by a factor of 0.24), compared to the remaining cows. In conclusion, there is a relationship between plasma PAG‐2 concentrations and the risk of abortion in Neospora‐infected dairy cows. Thus, plasma PAG concentrations measured using anti‐boPAG‐2 antiserum on Day 120 of gestation could serve as an indicator of the abortion risk in N. caninum infected animals; values <4.5 ng/ml indicating a high risk of abortion in chronically infected animals.  相似文献   

18.
Pregnancy‐associated glycoproteins (PAGs) constitute a large family of glycoproteins that are synthesized in the superficial layer of the ruminant placenta according to a spatial and temporal expression pattern. When PAGs are released in the maternal blood they can be used for pregnancy diagnosis, pregnancy follow‐up and for the monitoring of the trophoblastic function. Three different radioimmunoassay systems (RIA 1, RIA 2 and RIA 3) using antisera produced against PAG I67 (RIA 1), PAG55+62 (RIA 2) and PAG55+59 (RIA 3) were used in this investigation in order to measure the PAG concentration in plasma samples withdrawn from pregnant cows and heifers during different periods following artificial insemination (AI). These systems were able to detect PAG molecules in the maternal blood as early as 21 days after AI in different concentrations (RIA 1: 0.43 ± 0.24 ng/ml, mean ± SD; RIA 2: 0.48 ± 0.24 ng/ml; RIA 3: 0.64 ± 0.37 ng/ml). On days 32 and 42 RIA 2 (4.30 ± 1.32 ng/ml and 5.56 ± 1.95 ng/ml) and RIA 3 (4.17 ± 1.15 ng/ml and 5.60 ± 1.89 ng/ml) presented significantly (p < 0.0001) higher PAG concentrations than those of RIA 1 (2.43 ± 0.81 ng/ml and 4.01 ± 1.48 ng/ml), respectively. After day 21, significant correlations (p < 0.0001; r ≥ 0.929) were determined between the three systems. Additionally the three individual PAG profiles presented in this study showed that PAG molecules secreted in the maternal blood between 21 and 50 days after AI were better recognized by the RIA 2 and RIA 3 systems. This study clearly indicated that the ability of a RIA test to recognize PAG molecules in the maternal blood can be improved by carefully selecting the antiserum.  相似文献   

19.
Pregnancy-associated glycoprotein (PAG) concentrations were measured in buffalo cows starting from day 28 after breeding. Oestrus was synchronized in 10 buffaloes using two injections of 25 mg prostraglandin (PG)F2 α (Lutalyse®) at a 11-day interval. Blood sampling was conducted nearly twice weekly. Results indicated that plasma PAG concentrations in non-pregnant buffaloes were low (<0.20 ng/ml) during the whole experimental period (day 28 to 103), while in pregnant animals plasma PAG levels increased from day 28 (4.48 ± 0.92 ng/ml) until day 41 (27.27 ± 6.74 ng/ml), remaining high (20.71 ± 9.20 ng/ml) until day 103. Progesterone levels were significantly (p < 0.0001) higher in pregnant (3.51–4.80 ng/ml) than in non-pregnant buffaloes (0.28–1.52 ng/ml). A significant difference (p < 0.0001) in plasma PAG concentrations between pregnant and non-pregnant animals starting at day 28 after breeding suggests that PAG-radioimmunoassay could be suitable for pregnancy diagnosis in buffaloes during this period. In conclusion, PAG test offers the advantages that it requires a single plasma sample for early pregnancy diagnosis as well as the accuracy of the test for the detection of pregnancy as early as day 28.  相似文献   

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