对牛难产截胎术的改进

随着使役的减少牛的运动量出现了不足现象,在对肉牛的改良过程中,常出现本地牛所怀胎儿过大现象;此外,胎儿胎位胎向不正以及母牛产道特殊的生理结构导致牛难产发生的概率大幅度增加,给养殖户以及兽医工作者造成了极大的困扰。截胎术就是在难产时通过对胎儿进行切割使之能够从产道内取出的手术,是牛难产救助中的常用手术。近年来,笔者经过长期的兽医临床实践,改进了传统的截胎术,取得了良好的应用效果。现将其简介如下。     

母羊腹直肌断裂和腹膜破裂胎儿坠到乳房背侧

母羊腹直肌断裂和腹膜破裂胎儿坠到乳房背侧唐京彬曹玉军（山东省临沂市种鸡场，莒南２７６６００）由于母羊腹直肌不发达，胎羊体重过大，母羊在妊娠后期运动不慎，而导致腹膜、腹直肌突然破裂，使胎羊通过破裂孔坠入乳房背侧。本病主要发生在妊娠后期，尤其是临产前几天...     

母牛流产的预防与治疗

<正>在临床诊治的动物疾病中,牛的难产比较多。有产力性难产、产道性难产、胎儿性难产;胎向、胎位、胎势异常、胎儿过大、胎儿畸形、双胎都会导致母牛难产。由于牛的骨盆轴比较弯曲,分娩时不利于胎儿通过。难产一旦发生,容易引起犊牛死亡,也会危及母牛生命。生产实践证明,预防牛难产的发生,必须从配种时就抓起。1母牛难产的预防措施(1)对于子宫疾病引起的流产,应在配种前治疗,病情轻或胎水多的牛,给予丰富的营养,饲喂体积小的精料,限制饮水,     

治疗牛难产截胎术的改进

截胎术是牛难产救助中常用的手术。近年来临床上牛难产有大幅上升的趋势,其原因主要是：养牛的目的转为肉用为主,使役的减少造成运动不足;肉牛改良导致当地牛所怀的胎儿过大,再加上母牛产道的特殊生理结构以及胎儿胎位胎向不正等因素。因此,掌握截胎术在牛难产救助中有着非常重要的意义。     

手术治疗乳牛胎儿浸软一例

胎儿浸软常因胎儿骨片及分解产物不能全部从子宫排出或伴发子宫炎后贻子宫粘连而失去受孕能力。有的可能发生子宫穿孔,导致母牛死亡。我们曾采用过剖腹手术取出子宫内的胎儿骨片,治疗乳牛胎儿浸软一例,以后患牛恢复了受孕能力。 1236号牛,第2胎,妊娠5个半月时,从阴道排出深红褐色,混有胎儿骨片,诊断     

规模化猪场母猪流产的原因与对策

所谓母猪流产,即妊娠中断,是指母猪在怀孕期间,由于各种原因造成胚胎或胎儿与母体之间的生理关系发生紊乱,妊娠不能继续而中断。妊娠中断后胚胎或胎儿会发生不同的变化,如胚胎液化被母体吸收,胎儿干尸化,胎儿浸溶,死胎被排出体外或活胎被排出体外。     

以两种不同成纤维细胞为饲养层培养牛胚胎干细胞的比较

牛胚胎干细胞的培养一直未能确定最适合的饲养层,寻找一种适合于其生长的饲养层对于成功培养牛胚胎干细胞有重要意义。本研究以胎鼠和牛胎儿为材料,分别以含10%FBS的高糖DMEM和含10%FBS的DMEMF12为培养液,分离并且获得2～5代的胎鼠成纤维细胞和5～6代的牛胎儿成纤维细胞。在上述两种成纤维细胞为饲养层的条件下,采用含10%胎牛血清、0.1 mmol/Lβ-巯基乙醇、0.1 mmol/L非必须氨基酸、100 U/mL青霉素、0.05 mg/mL链霉素、20 ng/mL LIF和10 ng/mL bFGF的DMEMF12培养液培养牛胚胎干细胞,来寻找一种适合于牛胚胎干细胞培养的饲养层。结果表明,在相同的培养体系条件下培养牛胚胎干细胞,以胎鼠成纤维细胞为饲养层的贴壁率显著高于以牛胎儿成纤维细胞为饲养层的贴壁率(P0.05),以牛胎儿成纤维细胞为饲养层更利于胚胎滋养层的去除。     

不同共培养体细胞和胎牛血清浓度对牛体外受精后早期胚胎的影响

利用屠宰黄牛的卵母细胞经体外成熟(IVM)、体外受精(IVF)后的早期胚胎,与单层颗粒细胞(GC)、输卵管上皮细胞(BOEC)等体细胞共培养及在胎牛血清的胚胎培养液中的后续发育进行了研究,并探讨了其影响因素,以期筛选出最佳的体外培养条件。结果表明:使用GC和BOEC体外共培养牛体外受精后胚胎,均取得了较好的囊胚发育率;且牛体外受精后早期胚胎体外培养体系中,添加10%血清能有效地促进牛体外受精后胚胎的囊胚率。     

用截胎术治疗牛难产

截胎术是牛难产救助中常用的手术。特别是近年来临床上牛难产有大幅上升的趋势，其原因主要是养牛的目的转为肉用为主，使役减少造成运动不足。肉牛改良导致当地牛所怀的胎儿过大，再加上母牛产道的特殊生理结构以及胎儿胎位胎向不正等因素导致难产。因此，掌握截胎术在牛难产救助中有着非常重要的意义。笔者在长期的兽医临床实践中，对传统的截胎手术进行改进，取得了良好的效果。     

截胎术在肉牛难产中的应用

正截胎术是牛难产中常用的救助手术。近几年来临床上牛难产有大幅上升的趋势,其主要原因是养牛的以肉牛为目的,使役的减少造成运动不足;肉牛改良导致当地牛所怀的胎儿过大,再加上母牛产道的特殊生理结构以及胎儿胎位胎向不正等因素。因此,掌握截胎术在牛难产救助中有着非常重要的意义。笔者在长期的兽医临床实践中,对传统的截胎手术进行改进,取得了     

Multiple embryo-transplant offspring produced from quartering a bovine embryo at the morula stage

A non-surgical embryo collection was completed on a day 7 superovulated Chianina donor cow. Because all but two of the ova from the collection were unfertilised and a surplus of potential recipients was available, one embryo (an excellent quality late morula) was dissected into four equal portioned 'quarter' embryos using a simplified micromanipulation procedure. Each quarter embryo was then placed in a 0.25 ml French straw and non-surgically transplanted to four different crossbred beef recipient females. The remaining embryo was similarly transplanted to a herd mate recipient as an intact embryo. One recipient returned to oestrus, one recipient had an extended post transfer cycle and the two remaining recipients produced a live quarter embryo transplant calf each within 24 hours of the other. The intact embryo placed in a herd mate recipient did not produce a transplant calf. To the authors' knowledge, these transplant offspring are the first live births reported from a non-surgically collected later-stage bovine morula (day 7), which had been dissected into quarters and then individually transplanted non-surgically to recipient females. The procedure was relatively simple to perform and was completed in less than one hour.     

WT1基因组蛋白乙酰化修饰对细胞核重编程的影响

利用体细胞移植技术获得克隆动物的成功是几十年来生命科学领域取得的重大突破之一,这项技术引起了社会的广泛关注。然而,由于哺乳动物克隆效率低下,且克隆后代发育异常等问题,已成为目前制约动物克隆技术发展和应用的瓶颈。克隆动物中经常出现后代过大综合征（LOS）,该病导致克隆动物早产、难产和易夭折。LOS类似于人的伯-伟综合征（BWS）,BWS也称为Wlims瘤,表现为巨舌、内脏肿大等症状。研究发现BWS的发病机理与WT1基因（Wilms’tumor 1gene）异常表达有关。本文对体细胞核重编程和表观遗传学调控细胞重编程的研究进展进行综述,并对WT1基因组蛋白乙酰化修饰与体细胞重编程之间的联系进行简要介绍,以期为生命科学领域的进一步探索与研究提供借鉴。     

大白×梅山猪资源家系重要经济性状的分析

为了寻找控制重要经济性状的基因座位 ,我们在国内较早开始组建资源家系。利用 3头大白猪和 7头梅山猪作父母本 ,产生F1 。F1 随机交配产生F2 ,147头F2 个体记录了生长、胴体及肉质性状。对各性状进行统计分析 ,结果表明 ,各性状变异程度大、变异范围广 ,性状间有不同程度的相关 ,从一个侧面预示着QTL的存在 ;同时 ,这些性状的统计分析 ,为定位QTL时协变量的选择提供了参考价值。     

Births of freemartins derived from embryos reconstructed with ear fibroblasts.

Although the combination of artificial insemination (AI) and embryo transfer (ET) is effective for preventing large offspring syndrome in clone cattle production, it may cause freemartinism. In this study, 51 reconstructed embryos were transferred to artificially inseminated recipients. Of those 9 twin pregnancies, three delivered male and female offsprings. The females had tufts of long coarse hair and short blind pouch at the vaginal end. At necropsy, hypoplastic testicles and epididymis, which connected to the uterus through the spermatic cord, were found and seminal vesicles were also noted. All females had mixed sex chromosome configuration (60, XX and 60, XY). These results suggest that the combined ET program can cause freemartinism, which reduces the efficiency of clone cattle production.     

体细胞核移植技术在转基因动物研究中的应用

利用基因工程技术将目的基因整合入动物体细胞染色体中，并将其作为供体核移植入受体－－去核卵母细胞构成重建胚，然后将其移植入假孕母体，待其妊娠、分娩，便可得到经定向遗传修饰的转基因克隆动物。本文就这一领域的发展历史、研究现状、应用前景及存在的问题等方面作一概述。     

A study of the inheritance of a bleeding disorder in Simmental cattle

A study was designed to determine the inheritance pattern of a blood platelet aggregation disorder in Simmental cattle utilizing embryo transfer technology. A Simmental donor cow that had previously produced a calf with the platelet aggregation disorder was superovulated and mated to a bull that had also produced affected offspring. Twenty-seven calves were produced from the 63 (42.9%) embryos transferred. This somewhat lower than expected pregnancy rate is suggestive of an increased rate of embryo loss. Twenty-three of 25 (92%) calves had normal platelet aggregation patterns and 2 failed to show any evidence of platelet aggregation. Data are suggestive that inheritance is not simple Mendelian recessive. A more likely scenario is that the defect is the result of the inheritance of at least 2 genes, which is also consistent with the sporadic incidence reported in the population at large.     

The analysis of selected performance parameters following embryo transfer in the example of cattle

Gestation lengths and birth weight of calves from German Red Pied cows were used to analyse differences between embryo transplant offsprings (n = 76) and offsprings from natural pregnancy (n = 118). Furthermore differences were examined in milk traits between embryo transplant (n = 76) and not embryo transplant offsprings (n = 66) from the same dam (German Black Pied, n = 38). After embryo transfer gestation lengths was shorter, but only with a clear difference in first calving cows. Calves from embryo transfer had lower birth weights, because most of the time recipients are maiden. Even the age effect was taken into account, birth weights were about 1.5 kg lower for embryo transplant offsprings. For milk traits no significant differences could be ascertain between embryo transplant and not embryo transplant offsprings. With the exception of fat yield the estimated breeding values of the offsprings correspond to the expectations.     

Somatic Cell Nuclear Transfer in Horses

The cloning of equids was achieved in 2003, several years after the birth of Dolly the sheep and also after the cloning of numerous other laboratory and farm animal species. The delay was because of the limited development in the horse of more classical-assisted reproductive techniques required for successful cloning, such as oocyte maturation and in vitro embryo production. When these technologies were developed, the application of cloning also became possible and cloned horse offspring were obtained. This review summarizes the main technical procedures that are required for cloning equids and the present status of this technique. The first step is competent oocyte maturation, this is followed by oocyte enucleation and reconstruction, using either zona-enclosed or zona-free oocytes, by efficient activation to allow high cleavage rates and finally by a suitable in vitro embryo culture technique. Cloning of the first equid, a mule, was achieved using an in vivo -matured oocytes and immediate transfer of the reconstructed embryo, i.e. at the one cell stage, to the recipient oviduct. In contrast, the first horse offspring was obtained using a complete in vitro procedure from oocyte maturation to embryo culture to the blastocyst stage, followed by non-surgical transfer. Later studies on equine cloning report high efficiency relative to that for other species. Cloned equid offspring reported to date appear to be normal and those that have reached puberty have been confirmed to be fertile. In summary, horse cloning is now a reproducible technique that offers the opportunity to preserve valuable genetics and notably to generate copies of castrated champions and therefore, offspring from those champions that would be impossible to obtain otherwise.     

羔羊诱导卵泡发育及其应用的研究进展

幼畜体外胚胎移植(Juvenile In Vitro Embryo Transfer,JIVET)技术是利用幼畜对外源激素敏感的生理特点,采用外源促性腺素诱导幼畜卵泡超数发育,结合卵母细胞体外成熟、体外受精和胚胎移植等技术生产后代,该技术体系的研究与应用可以充分发挥优秀母畜繁殖潜能,快速扩繁良种畜群。近年来,国内外对绵羊JIVET技术研究比较多,但应用JIVET技术生产体外胚胎的效率低下、效果不稳定仍然是一个普遍问题。迄今为止,大多数的研究致力于加强供体羔羊选择、优化激素处理方案以及提高羔羊卵母细胞体外发育能力等方面。本文综述了羊JIVET技术的原理与最新研究进展以及影响JIVET技术效率所存在的内因和外因,旨在为深层次探索羔羊卵子发生和卵泡发育调控机制提供理论依据,促进JIVET技术的研究与应用。     

New Biotechniques and their Consequences for Farm Animal Welfare

Contents This paper considers (potentially) harmful consequences of new biotechnologies for farm animal welfare. The most important new biotechnologies that are currently used in farm animals breeding and husbandry include: multiple ovulation and embryo transfer (MOET) and in vitro embryo production (IVP). Cloning by nuclear transfer (NT) and transgenesis are still in development and mainly applied for experimental purposes with the prospect of a more widespread practical implemention in the future. Evidence is presented showing that generally accepted technologies such as MOET and IVP, relative to in vivo procedures, can result in a host of deleterious side-effects commonly known as the large offspring syndrome (LOS). Likewise, NT and transgenesis, which also typically include several in vitro reproductive manipulations, have clearly been associated with the occurrence of LOS symptoms. It is argued that transgenesis may constitute one additional set of factors that may negatively affect farm animal welfare: the expression of the transgene and the concomitant synthesis and release of a protein. NT might lead to incompletely reprogramming of the transferred genome. It is suggested that the introduction of new biotechnologies into farm animal husbandry should be accompanied by scientifically valid and systematic studies into the effects on animal welfare, with the help of a comprehensive welfare protocol.