牛活体采卵技术及其在胚胎体外生产中的应用

自第1头体外生产胚胎(IVP)牛诞生和非手术活体采卵(OPU)技术在牛上应用以来,为了改进IVP和OPU技术,许多研究者致力于提高牛IVP和OPU技术的效率.时至今日,OPU和IVP技术均已成为成熟的技术.阐述了过去十几年中OPU和IVP技术的主要研究成果和研究进展,并总结了该技术的应用历史、应用现状和应用前景.     

牛活体采卵技术研究进展

活体采卵(Ovum Pick-up,OPU)可生产大量遗传品质优良、系谱明确的体外受精胚胎,成为牛胚胎移植的重要胚胎来源,在奶牛和肉牛生产中得到广泛应用。本文综述了牛OPU技术特点和优势,重点分析了影响OUP效率的因素,以期为牛OUP胚胎生产提供参考。     

奶牛活体采卵与屠宰场卵巢卵子体外生产胚胎的效果比较

先利用屠宰场卵巢获得的卵母细胞进行体外培养试验.在建立了培养体系获得较稳定的囊胚率的基础上,再利用具有优良乳用遗传性状的老龄奶牛进行活体采卵(OPU),获得的卵子进行体外胚胎生产,对奶牛活体采卵与屠宰场卵巢卵子体外生产胚胎的效果进行了比较.同时对奶牛重复OPU的效果及OPU卵子的培养天数对妊娠率的影响因素等进行探讨,试图为研究和生产建立一个高效的活体采卵体外胚胎生产方法.结果表明:(1)活体采卵获得的卵母细胞从形态以及后期的发育情况均明显差于屠宰场卵巢获得的卵子;OPU法的卵裂率、囊胚率(70.5%、18.3%)明显低于从屠宰场卵巢获得的卵子的卵裂率、囊胚率(75.1%、34.8%)(P＜0.01).(2)不同个体采集卵子数量差异明显(5.92枚/头与1.4枚/头)(P＜0.05).(3)同一头奶牛每次采卵数之间无显著差异,但有波动性变化.(4)奶牛OPU卵子经培养在第6 d或第7 d发育至囊胚的胚胎移植妊娠率高于第8 d发育至囊胚的胚胎.     

全日制放牧BMY牛的活体采卵-体外胚胎生产-胚胎移植研究

为建立BMY牛的活体采卵(OPU)-体外胚胎生产(IVP)-胚胎移植(ET)快速扩繁技术体系,从人工草地全放牧牛群中选择健康的经产空怀BMY牛作为供体(n=14)集中OPU一次;卵母细胞经TCM-199体外成熟培养(IVM)、Fert-TALP液体外受精(IVF),受精卵用合成输卵管液(SOF)体外培养(IVC)生产胚胎;BMY牛受体(n=81)用CUE-MATETM孕酮阴道栓+EB+FSH+PG方法同期发情处理,对黄体合格的移植OPU-IVP来源鲜胚。研究结果表明:①OPU头均获卵母细胞23.50枚,获10枚以上卵母细胞的供体占85.7%;IVP的平均囊胚数和可用胚数分别为5.21和4.00枚;OPU前8～9d卵巢上有黄体(CL)的供体,头均获卵母细胞数及IVP的囊胚数、可移植胚数、囊胚率和可移植胚率分别比对照组高7.28枚(P<0.05)、7.29枚(P<0.05)、6.00枚(P<0.05)、27.3%(P<0.01)和23.2%(P<0.01);②受体黄体合格率69.1%(56/81),胚胎移植妊娠率37.5%(21/56),产犊率35.7%(20/56);③受体在胚胎移植时注射GnRH,其妊娠率比对照组高16.2%(P>0.05)。结果显示,BMY母牛具有良好的OPU潜力,但个体间差异较大;可通过严格供体选择及改善IVP技术等措施,实现OPU-IVP效率最大化。CUE-MATETM+EB+FSH+PG同期发情处理方法适于在牛规模化胚胎移植(ET)和人工授精(AI)中应用。综合应用OPU、IVP、同期发情和ET技术是加快优良BMY牛扩繁的重要途径之一。     

荷斯坦奶牛与和牛活体采卵-体外受精（OPU/IVF）体系的建立及应用

[目的]研究牛活体采卵-体外受精（ovum pick-up and in vitro fertilization,OPU/IVF）体系,建立高效的牛体外胚胎生产系统。[方法]以从屠宰场采集的健康牛新鲜卵巢为试验材料,进行卵母细胞体外成熟、体外受精、体外胚胎培养相关条件的摸索,重点考查体外胚胎培养液中添加瘦素（leptin）对囊胚率的影响。选取13～15月龄健康荷斯坦奶牛及和牛各10头作为供体,进行活体采卵、卵母细胞体外成熟、体外胚胎生产,记录可用卵数及可用囊胚数,统计卵裂率、囊胚率;2个品种牛的体外冷冻胚胎解冻后,以荷斯坦奶牛为受体进行胚胎移植,移植后45 d统计妊娠率。[结果]添加30 U/mL的leptin可以显著（P<0.05）提高屠宰场来源牛体外胚胎的囊胚率。随机选择供体牛活体采卵,平均每头荷斯坦奶牛获得可用卵7.5枚,平均每头和牛获得可用卵8.1枚;荷斯坦奶牛及和牛的卵裂率分别为84.00%、82.71%,二者差异不显著（P>0.05）。体外培养条件下,平均每头荷斯坦奶牛获得可用囊胚4.3枚,平均每头和牛获得可用囊胚3.7枚;荷斯坦奶牛的囊胚率（57.33%）显著...     

奶牛活体采卵及体外生产胚胎技术研究

采用盲吸法对17头空怀奶牛和25头青年奶牛进行活体采卵,采集卵母细胞199枚,平均每头采得卵母细胞4.74枚,其中,可用卵母细胞139枚,平均每头获可用卵母细胞3.3枚,经体外系统培养,获受精卵101枚,发育至桑葚胚和囊胚期阶段35枚,受精率和胚胎发育率分别为72.66%和25.17%.选择11枚胚胎移植黄牛受体11头,妊娠4头,妊娠率为36.36%,正常产犊4头.     

牛活体采卵技术的研究进展

牛活体采卵是继牛体外受精（IVF）、胚胎移植（ET）技术之后推出的一项新的胚胎工程技术。文章就目前牛活体采卵技术最新进展及其几种常用方法的使用效果进行了阐述,综述了影响牛活体采卵效果的因素,最后对牛活体采卵技术的前景作了展望。     

水牛活体采卵体外生产胚胎技术

本研究应用B超引导阴道穿刺法,对40头尼里-拉菲和摩拉水牛连续3次采卵,采卵间隔为3 d.共采卵120头次.共穿刺卵泡935个,采集卵母细胞643枚,可用卵母细胞为456枚,卵母细胞回收率为68.77%(643/935),卵母细胞可用率为70.92%(456/643),头均可用卵母细胞为(3.80±0.23)个.第1、2、3次采卵头均回收可用卵母细胞数分别为(3.82±0.50)、(3.82±0.35)、(4.05±0.43)枚,差异不显著(P＞0.05).收集的卵母细胞经体外成熟、体外受精和受精卵与颗粒细胞单层体外共培养,受精后48 h分裂率为56.36%(257/456),囊胚率为20.39%(93/456).2个品种水牛的头均可采卵泡数、头均回收卵母细胞数和囊胚率均无显著差异.这表明,在B超引导下进行连续活体采卵,并利用卵母细胞进行体外受精生产胚胎是可行的. 3),头均可用卵母细胞为(3.80±0.23)个.第1、2、3次采卵头均回收可用卵母细胞数分别为(3.82±0.50)、(3.82±0.35)、(4.05±0.43)枚,差异不显著(P＞0.05).收集的卵母细胞经体外成熟、体外受精和受精卵与颗粒细 单层体外共培养,受精后48 h分裂率为56.36%(257/456),囊胚率为20.39%(93/456).2个品种水牛的头均可采卵泡数、头均回收卵母细胞数和囊胚率均无显著差异.这表明,在B超引导下进行连续活体采卵     

淘汰牛连续活体采卵效果及影响因素分析

为挖掘利用具有优秀遗传性能的淘汰母牛的卵泡资源,本实验开展淘汰牛连续活体采卵的效果及影响因素研究。选取6头5～6岁无卵巢疾病的淘汰西门塔尔牛,分别于7、10、11月和12月每间隔4 d进行1次活体采卵,每月最高进行5次活体采卵,记录每头次的卵泡抽吸次数、获卵数、优质卵数,并对影响活体采卵效果的因素进行分析。结果表明：平均头次获卵数和优质卵数分别为4.61枚和2.22枚,卵子回收率和优质卵率分别为47.21%和49.13%;试验牛的平均头次获卵数无显著差异,但第1次活体采卵的卵子回收率高于第2～5次（P<0.05）,第2次活体采卵的优质卵率显著高于第5次;采卵月份对平均头次获卵数、回收率和优质卵率无显著影响;采卵次数与采卵月份间无交互作用（P>0.05）。综上,淘汰牛连续活体采卵的效果相对稳定,连续采卵次数对卵子回收率、优质卵率具有一定影响。     

成年奶牛与青年奶牛活体采卵效果分析

采用盲吸法对17头空怀奶牛和25头青年奶牛进行活体采卵,采集卵母细胞199枚,平均每头采得卵母细胞4.74枚,其中,可用卵母细胞139枚,平均每头获可用卵母细胞3.3枚,经体外系统培养,获受精卵101枚,发育至桑葚胚和囊胚期阶段35枚,受精率和胚胎发育率分别为72.66%和25.17%。     

奶牛胚胎移植产业化及相关技术的应用

1 奶牛胚胎移植产业化的概念 奶牛的人工授精，特别是冷冻精液的普及是奶牛繁殖技术的一次重大的革命，对全世界奶牛业的发展和效益的提高起到了重要的推动作用。充分发挥了优秀种公牛的利用率，加速了奶牛的遗传改进速度。奶牛胚胎移植是继人工授精之后奶牛繁殖技术的又一次革命。充分发挥了优秀母牛的遗传和繁殖潜力，极大地增加了优秀个体的后代数。这项技术从……     

奶牛胚胎移植技术应用进展

胚胎移植技术是胚胎工程的重要组成部分,目前在奶牛上得到了广泛的应用。与传统的胚胎移植技术相比,目前奶牛胚胎移植技术应用了更先进的生物技术,包括胚胎冷冻、胚胎分割、融合、卵核移植、胚胎性别鉴定、卵母细胞的体外培养与体外受精及基因导入等。本文在叙述了奶牛胚胎移植技术的发展过程基础上,对胚胎移植的前景也作了一定分析。     

Leptin和ITS对牛卵母细胞体外培养和胚胎生产的影响

利用Leptin和ITS促进体外成熟和体外培养的牛卵母细胞的发育和质量,探讨提高胚胎体外生产的质量和数量的方法和技术。试验1：体外受精胚胎的培养液：添加BSA的KSOM中添加10mL/L浓度的ITS,结果使胚胎的桑椹胚率和囊胚率显著（P〈0.05）高于培养液中不加ITS的对照组（桑椹胚率：43.48%vs29.07%,囊胚率：22.83%vs11.63%）,卵裂率、正常分裂率和8细胞率与对照组差异不显著（P〉0.05）。试验2：在卵母细胞的体外成熟液中添加10μg/L具有生物学活性的重组鸡Leptin成熟肽融合蛋白,Leptin处理组和对照组卵母细胞经体外成熟、受精后转入加有10mL/LITS的KSOM培养液进行体外培养。试验组卵裂率和正常分裂率极显著（P〈0.01）高于对照组（88.96%vs66.81%和61.11%vs29.36%）,8细胞率显著（P〈0.05）高于对照组（84.84%vs69.57%）。Leptin处理的卵母细胞在受精后的桑椹胚率和囊胚率与对照组差异不显著,但最后的囊胚数量较对照组增加1倍多,分别为IVF卵母细胞总数的14.8%和6.4%（P〈0.01）。这说明,添加Leptin对牛卵母细胞体外成熟有促进作用,可显著提高卵母细胞受精后早期胚胎的卵裂率、正常分裂率和8细胞率;加入ITS则能提高桑椹胚率和囊胚率;而Leptin和ITS的按顺序结合使用,则能大大增加体外生产胚胎的桑椹胚和囊胚的数量,从而提高胚胎体外生产的效率。     

Improved embryo development in Japanese black cattle by in vitro fertilization using ovum pick-up plus intracytoplasmic sperm injection with dithiothreitol

The purpose of this study was to determine whether dithiothreitol (DTT) treatment of sperm and ethanol activation improve embryo production by intracytoplasmic sperm injection (ICSI). Further, we compared ICSI with standard in vitro fertilization (IVF) in oocytes obtained from cattle. We demonstrated that DTT reduced the disulfide bond in the bovine sperm head. Using oocytes obtained from a slaughterhouse, ICSI-DTT treatment without ethanol showed the highest rate of blastocyst formation. We applied these results to fertilization using ovum pick-up (OPU). Eleven Japanese black cattle served as donors for OPU plus standard IVF (OPU-IVF). Of them, four donors with low embryo development rates were selected to determine whether embryo development was enhanced by OPU plus ICSI (OPU-ICSI). We assessed effects on embryo development following IVF and ICSI in oocytes obtained using OPU. Blastocyst rates were significantly higher for OPU-ICSI than for OPU-IVF. Our results suggest that OPU-ICSI improves the blastocyst development rate in donors with low embryo production compared with the standard OPU-IVF.     

Effect of suckling on embryo production by repeated ovum pick-up before and after timed artificial insemination in early postpartum Japanese black cows

We investigated whether suckling would affect embryo production of cows bred by timed artificial insemination (TAI) following an ovulation synchronization protocol combined with ovum pick-up and progesterone releasing intravaginal device (OPU-PRID-TAI protocol). The number of oocytes and transferable embryos collected by repeated OPU, performed before and after TAI, were recorded. A total of 14 Japanese Black cows were divided into weaned (n=7) and suckled groups (n=7). All 14 cows were treated with OPU on day 0 (the first day of treatment) and then with a PRID for 9 days. Prostaglandin F(2alpha) analog was administered on day 7, GnRH analog was administered on day 10 (36 h after removal of the PRID) and TAI was performed 12 h later. Ovulation was confirmed by palpation per rectum the following day. After TAI, additional OPU sessions were performed on days 18, 25 and 32. The synchronized ovulation rates of the weaned and suckled groups were 100 and 85.7%, and the conception rates were 71.4 and 42.9%, respectively. Immature oocytes were fertilized and cultured in vitro. The numbers of oocytes collected and blastocysts generated were similar between the individual OPU sessions in both groups. However, the total numbers of oocytes collected, cultured oocytes, cleavage embryos and blastocysts as well as the proportions of cleavage embryos and blastocysts to cultured oocytes were all significantly (P<0.05) greater in the weaned group compared with the suckled group. These results suggest that the OPU-PRID-TAI protocol has the potential to produce a significant number of good-quality embryos in vitro after repeated OPU in early postpartum weaned Japanese Black cows. To collect more oocytes and produce more embryos, we suggest that calves be removed from cows scheduled for treatment using this protocol.     

影响山羊体外胚胎生产的主要因素

研究了不同成熟培养时间（21、242、7 h）、FSH剂量（0、0.02、0.04、0.06 AU/mL）和激素组合（FSH＋LH＋E2、FSH＋LH、LH＋E2、FSH＋E2）、氨基酸以及负压低氧条件（-300 mmHg2、%CO28、%～10%O2）对山羊卵母细胞体外成熟/体外受精（IVM/IVF）的影响。结果表明：山羊卵母细胞成熟培养以24～27 h较为适宜;添加FSH组的受精卵裂率显著高于未添加组（P〈0.01）,添加剂量以0.02～0.04 AU/mL效果为最佳;LH对山羊的IVM/IVF无显著影响;E2添加对山羊IVM/IVF有负面影响,使囊胚发育率显著降低（P〈0.05）。在成熟液中添加必需氨基酸（EAA）和非必需氨基酸（NEAA）均能显著提高受精卵裂率（P〈0.05）。负压低氧环境对山羊卵母细胞的体外成熟无显著影响,但是不利于山羊的体外受精,使受精卵裂率极显著降低（P〈0.01）;负压低氧环境对提高胚胎发育率的作用不明显。     

Anti-Muellerian hormone levels in plasma of Holstein-Friesian heifers as a predictive parameter for ovum pick-up and embryo production outcomes

The aim of this study was to investigate whether plasma anti-Muellerian hormone (AMH) levels of Holstein-Friesian heifers could be used to predict ovum pick-up (OPU) and embryo production outcomes. Plasma samples and data were collected from 64 heifers, which underwent repeated OPU with subsequent in vitro embryo production followed by embryo flushing after superovulation. AMH levels were significantly positively correlated with the number of follicles aspirated per OPU session (r = 0.45), recovered oocytes per OPU (r =0.43) and in vitro produced embryos per OPU (r = 0.28). No significant correlations between AMH and in vivo produced embryos were ascertained. Our results suggest that correlations between AMH and outcomes of an OPU-IVF program are too low to use AMH as a precise predictive parameter for the success of a particular OPU procedure in Holstein-Friesian heifers. However, AMH can help to identify groups of very good or very poor oocyte donors.