Embryo Transfer in the Canadian Cattle Industry: Canada's Regulatory Approach

In 1978, Canada was the first country to regulate animal embryo transfer in a manner similar to regulations for artificial insemination. Research has shown that the risk of disease transmission by bovine embryos is minimal therefore regulations are evolving to recognize this potential. The Canadian Embryo Transfer Association plays a key role in regulatory decisions. Importing embryos is based on risk assessment and on the impact of potentially introduced disease agents. Export strategy is based on negotiation of valid conditions, on effective certification of embryos and on full involvement at the international level.     

牛体外受精早期胚胎与小鼠胎仔成纤维细胞共培养的研究

探讨了人工合成培养液ＣＲ１ａａ和小鼠胎仔成纤维细胞对牛体外受精早期胚胎体外发育的影响。结果表明，牛体外受精卵在ＣＲ１ａａ液中的卵裂率达７６．２％，８细胞胚的比率达４４．８％。小鼠胎仔成纤维细胞能够显著促进牛体外受精的早期囊胚以上胚胎的发育。牛体外受精后第５、６天的早期胚胎分别与小鼠胎仔成纤维细胞共培养，在受精后第７天发育至囊胚以上的比率分别达１９．８％和２４．６％；受精后第８天，孵化的囊胚比例分别达５．２％和７．５％。实验表明，受精后第５、６天的牛体外受精早期胚胎与小鼠胎仔成纤维细胞共培养，可显著提高扩张囊胚和孵化囊胚数量。小鼠成纤维细胞对胚胎发育的支持作用取决于胚胎发育阶段     

B超诊断技术在母牛繁殖生产和胚胎移植工作中的应用

B超诊断技术的用途很广泛,应用最多的是在动物生殖系统。迄今为止,还没有一种诊断仪器能像B超诊断仪那样受到畜牧工作者的青睐。B超诊断技术的推广现已部分取代传统方法,奠定了B超诊断技术在畜牧生产中的重要地位。B超与传统的X射线、X射线CT成像、核磁共振(NMR)成像、放射性核     

一步吸管法奶牛胚胎移植效果观察

一步吸管法奶牛胚胎移植是相对于奶牛胚胎在冷冻保存和解冻过程中用庶糖二步清除防冻剂而言的、更简便的一种清除防冻剂的方法。即在吸管内无胚胎段吸入0．25moL／L的蔗糖液进行冷冻，解冻后使有胚胎的保存液与蔗糖液混合，剪去上段漂浮的甘油，直接移植。Renard和Leibo等用此法相继在1982年和1984年获得36．7％和45．2％的受胎率。郭志勤用此法在1987年以产犊后计算妊娠率达41．38％。     

影响牛胚胎移植效果的因素分析

近年来,胚胎移植技术在动物繁殖领域快速发展,且在生产中取得了一定的成就。但是由于胚胎移植成功率受到多种因素的影响,为该技术的推广增加了难度。本文分析了影响牛胚胎移植成功率的胚胎质量、冷冻技术、供体和受体牛等关键因素,以期提高胚胎移植的成功率,使胚胎移植技术能更广泛的应用于我国的牛养殖业,推动其产业化及现代化的发展进程。     

Development and Status of Cattle Embryo Cloning in Germany

Contents: A review about experiments in bovine embryo cloning performed by different working groups in Germany is given. The procedure is shortly described and the achieved results are specified. Average enucleation rates in the experiments were 58–74%, electrofusion rates were 31 to 85%. Between 3 and 17% of the in vitro cultured embryos cleaved to transferable embryos. The first calf emerging from nuclear transfer in Germany was born in August, 1992. A clone of three identical calves was given birth in April, 1993. Four months later a calf was born, which exclusively emerged from in vitro techniques (in vitro maturation of recipient oocytes, in vitro production of blastomere donor embryo, in vitro culture of cloned embryos). Finally some future aspects of bovine embryo cloning in Germany are illustrated.     

Influence of Ovulation Status,Seasonality and Embryo Transfer Method on Development of Cloned Porcine Embryos

To improve pig cloning efficiency, the present study evaluated the effect of ovulation status, seasonality and embryo transfer (ET) method on in vivo development of cloned porcine embryos. Cloned embryos were transferred to surrogate mothers on the same day of somatic cell nuclear transfer. In pre‐ovulation stage (PO), pregnancy rate (PR) and delivery rate (DR) were 36.3% and 9.4%, respectively. In post‐ovulation stage, 22.7% PR and 2.1% DR were recorded (both PR and DR are significantly higher in PO). When ET was performed during winter (December–February), spring (March–May), summer (June–August) and autumn (September–November), the PRs were 13.4%, 37.3%, 24.6% and 51.0%, while DRs were 0%, 12.7%, 4.3% and 7.8%, respectively. The highest PRs were recorded in autumn groups. However, DRs were significantly lower in autumn (7.8%) group compared with spring (12.7%) group. The PR was the lowest and no piglets were born in winter group, which might be because of the effect of low temperature during ET. To overcome the low PR in winter group, 0.25 ml straws were used for ET to minimize exposure time of embryos to ambient temperature. The straw ET group showed significantly higher PR in the winter group (23. 9%) compared with the conventional catheter‐loading group (7.7%). We suggest that using PO recipient and ET in spring is the best condition for pig cloning. In addition, alternative method to reduce cold shock during ET in winter is necessary.     

牛体外受精胚冷冻保存的研究

对牛卵泡卵母细胞体外受精（ＩＶＦ）１６８ｈ的致密桑椹胚、囊胚用常规快速冷冻法、预冷和不预冷的超快速冷冻法进行了冷冻保存试验。结果表明：ＩＶＦ囊胚采用含１０％甘油的常规快速冷冻法、含２．１ｍｏｌ／Ｌ甘油和０．２５ｍｏｌ／Ｌ蔗糖预冷５ｍｉｎ的一步冷冻法及含２５％甘油和２５％乙二醇预冷５ｍｉｎ的玻璃化冷冻法等３种方法进行冷冻保存，解冻后的继续发育率（６８．０％，５９．０％，６５．７％）均无显著差异（Ｐ＞０．０５），可用快速、简便、预冷的一步冷冻法或玻璃化冷冻法替代常规快速冷冻法；ＩＶＦ致密桑椹胚可用一步冷冻法（２．１ｍｏｌ／Ｌ甘油＋０．２５ｍｏｌ／Ｌ蔗糖）和玻璃化冷冻法（２５％甘油＋２５％乙二醇或２５％甘油＋２５％１，２－丙二醇）进行预冷的超快速冷冻保存；冻前预冷（５ｍｉｎ）能显著提高ＩＶＦ囊胚的冻后形态正常率和继续发育率（Ｐ＜０．０５）；ＩＶＦ囊胚冷冻—解冻后的继续发育率高于ＩＶＦ致密桑椹胚。     

焦虫病对牛胚胎生产的影响报告

利用进口加系肉用型西门塔尔优秀后代和美加系优秀种公牛冻精生产胚胎,改良本地肉牛,有利于高效地利用引进种质,加快我国肉牛品种改良的速度.目的:本文评估实施胚胎生产过程中,供体母牛在放牧中导致焦虫病,对胚胎生产结果及冻胚移植成功率影响.方法:本文选择40头10-16月龄加系西门塔尔种母牛进行超数排卵处理生产体内胚胎.在超排...     

Ultrasound in the Gynaecological Diagnosis in Bovine with Respect to Embryo Transfer*

The use of ultrasonography in cases of embryo transfer in cattle provides valuable additional information. Indications are the examination of uterus and ovaries, control of superovulation, ultrasound-guided follicle punction for oocyte collecting, pregnancy diagnosis from day 20 and monitoring of early pregnancy for occurrence of embryonic death. Especially the ultrasound-guided follicular aspiration of oocytes seems to be a successful path for a avoiding superovulation. Inhalt: Die Sonographie in der gynäkologischen Diagnostik unter dem Aspekt des Embryotransfers Durch die Sonographie können für Arbeiten in Zusammenhang mit dem Embryotransfer, wie am Beispiel des Rindes gezeigt wurde, wertvolle zusätzliche Informationen erhalten werden. Indikationen für den Einsatz von Ultraschall sind die Funktionsüber-prüfung von Uterus und Ovarien, die Kontrolle der Superovulation, die Oozytengewinnung unter sonographisch überwachter Follikelpunktion mit transvaginalern Zugang, die Graviditätsdiagnose ab dem 20. Tag und die Überwachung der Frühgrauidität, wobei vor allem das frühzeitige Erkennen einer embryonalen Mortalität von Bedeutung ist. Besonders die transvaginale Follikelpunktion zur Oorytengewinnung scheint ein vielversprechender Weg zu sein, wenn eine Superovulation vermieden werden soll oder die betreffenden Tiere aufeine hormonale Stimulation nicht reagieren.     

胚胎移植受体牛同期发情及受胎效果的研究

本试验分别采用CIDR+E2法和两次PGF2α子宫输注法,对胚胎移植受体牛做同期发情处理,鲜胚移植观察其妊娠情况。试验结果表明两种处理方法的受体牛在24~48h发情率分别为85.5%和51.6%,两者之间差异显著(P<0.05)。移植前对受体牛进行黄体检查,黄体合格率分别为79.3%和77.8%,差异不显著(P>0.05);受胎率分别为45.8%和42.4%,差异不显著(P>0.05)。24h后观察发情,6.5d直检,黄体A、B级者用于移植。     

奶牛同期发情和冷冻胚胎移植试验

为了扩大优质奶牛数量,加快奶牛品种改良速度,广州珠江牛奶有限公司从澳大利亚进口一批奶牛冷冻胚胎。并于2002年11～12月进行了2次同期发情处理和冻胚移植。1材料1.1胚胎奶牛冻胚购于澳大利亚RAB动物基因公司,155枚均为1级荷斯坦牛胚胎。1.2受体牛全部选自广州珠江牛奶有限公司的荷斯坦牛,年龄在1.5～6.0岁,胎次在0～4胎之间。1.3使用药品和工具1.3.1Estrumate(前列腺素F2a类药物),含氯前列烯醇250μg/mL,氯甲酚B.P0.1%(w/v),后者用于抗菌。由澳大利亚Schlering-ploughAnimalHeath公司生产。1.3.2两种奶牛发情鉴定器(Kamar和EstrusAl…     

Factors Affecting the Development of Somatic Cell Nuclear Transfer Embryos in Cattle

Nuclear transfer is a complex multistep procedure that includes oocyte maturation, cell cycle synchronization of donor cells, enucleation, cell fusion, oocyte activation and embryo culture. Therefore, many factors are believed to contribute to the success of embryo development following nuclear transfer. Numerous attempts to improve cloning efficiency have been conducted since the birth of the first sheep by somatic cell nuclear transfer. However, the efficiency of somatic cell cloning has remained low, and applications have been limited. In this review, we discuss some of the factors that affect the developmental ability of somatic cell nuclear transfer embryos in cattle.     

浅谈胚胎移植在黄牛品系繁育中的应用

略述了胚胎移植技术在基础理论研究及畜牧生产中的应用,论述了应用胚胎移植技术开展鲁西黄牛品系繁育的可能性并提出了初步的实施方案。     

白绒山羊性控胚胎生产及移植应用研究初探

应用X性控冷冻精液对超排供体白绒山羊进行人工授精,生产性控胚胎并进行鲜胚移植。结果发现,①用性控冻精和鲜精输精的供体母羊,平均卵子回收数分别为13.3和12.5枚,其中性控冻精组受精卵比例为29.6%（55/186）,极显著低于鲜精组94.0%（281/299）的比例（P<0.01）;②性控胚胎和普通胚胎移植受体母羊产羔率分别为42.2% 和58.1% ,二者差异极显著（P<0.01）;③性控胚胎移植受体母羊所产羔羊雌性所占百分数为100%,极显著高于普通胚胎移植（P<0.01）。表明通过白绒山羊X、Y精子分离、人工授精生产性控胚胎,同时结合胚胎移植技术,可以达到按照生产实际中的意愿得到性别控制子代白绒山羊的目的。     

摇摆病奶牛体内铜状态及其与NO水平的关系

为探明枘本中反映铜状态的几个重要标识与奶牛摇摆病之间的关系，并阐述奶牛体内NO水平及自由基的含量在该病发生中的作用，实验抽样测试了病区及非病区同年生奶犊牛血清铜、全血铜含量及血浆铜氧化酶（CP）、血清超氧化物歧化酶（CuZn-SOD）的活性；同时也检测了全血总自由基相对含量及血清NO含量。实验结果表明：病区奶牛化物歧化酶CuZn-SOD活性极显著地高于非病区奶牛（P＜0.01），并且病区发病奶牛与临床健康奶牛相比，该酶活性差异显著（P＜0.05）；病区奶牛CP活性显著低于非病区，同时病区临床健康牛与病牛间该酶活性差异显著（P＜0.05）；发病牛与病区临床健康牛的血清铜及全血铜之间的差异不显著（P＞0.05）；病区奶牛NO含量显著低于非病区而自由基含量显著高于非病区。结论 CuZn－SOD及CP更能反映机体内缺铜的程度；铜缺乏导致的机体自由基堆积和NO水平的改变也是该病发生的重要因素。     

新疆塔城地区牛胚胎移植现状问题及对策

本文简要地介绍了塔城地区牛胚胎移植的现状,通过分析胚胎移植工作开展中存在的问题,提出了塔城地区牛胚胎移植的发展思路。     

牛胚胎移植及后代在高寒地区适应性观察试验

互助县在2001-2004年先后从新疆呼图壁种牛场胚胎工程中心引进不同品种牛冷冻胚胎172枚,进行了胚胎移植试验.结果表明：平均受胎率为41.86%,产犊成活率为91.67%.胚胎移植所产的黑白花、安格斯、西门塔尔、利木赞犊牛平均初生重、6月龄重、12月龄重显著高于同龄本地黄牛（P＜0.01）;周岁平均日增重显著高于同龄本地黄牛（P＜0.01）;且胚胎移植后代牛的体尺也相应高于本地黄牛.胚胎移植后代牛的生长发育良好,在青海高寒地区具有良好的适应性.     

Effect of Embryo Density on In vitro Developmental Characteristics of Bovine Preimplantative Embryos with Respect to Micro and Macroenvironments

To overcome developmental problems as a consequence of single embryo culture, the Well of the Well (WOW) culture system has been developed. In this study, we aimed to examine the effect of embryo densities with respect to both microenvironment and macroenvironment on developmental rates and embryo quality to get a deeper insight into developmentally important mechanisms. WOW diameter and depth significantly affected developmental rates (p < 0.05). WOWs with diameter of 500 μm reached significantly higher blastocyst rates (32.5 vs 21.1% vs 20.3%) compared to embryos cultured in WOWs of 300 μm diameter or plain cultured controls. Embryos cultured in WOWs with 700 μm depth reached significant higher developmental rates compared with embryos cultured in WOWs of 300 μm depth and control embryos (30.6 vs 22.6% vs 20.3%). Correlation of the embryo per WOW volume with developmental rates was higher (r² = 0.92, p = 0.0004) than correlation of WOW diameter or WOW depth with developmental rates. However, the embryo per WOW volume did not affect differential cell counts. An embryo per culture dish volume of 1 : 30 μl was identified to be optimal when the embryo per WOW volume was 1 : 0.27 μl increasing developmental rates up to the level of mass embryo production. Giving the opportunity to track each embryo over the complete culture period while keeping high developmental rates with normal mitotic dynamics, the results of this work will provide benefit for the single culture of embryos in human assisted reproduction, mammalian embryos with high economic interest as well as for scientific purpose.