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现代动物繁殖技术包括人工授精、同期发情、胚胎移植、胚胎分割、胚胎嵌合、体外受精、克隆技术和性别控制等等,其中人工授精和胚胎移植在现代畜牧业生产中发挥着极其重要的作用,尤其是人工授精技术,是迄今为止应用最广泛并最有成效的繁殖技术. 相似文献
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<正> 绵羊胚胎技术是家畜生物工程技术的重要组成部分,其中属于细胞遗传工程的有胚胎移植、胚胎分割、胚胎冷冻,属于分子遗传工程的有胚胎嵌合、胚胎培养和体外受精。现就这些方面的研究进展状况简介如下。1 胚胎移植1.1 自Heape(1891)发明胚胎移植技术距今已有近百年的历史了。Warwick在1934年,Lop-Yrin 相似文献
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1在动物繁殖育种中应用
胚胎工程是指对动物早期胚胎或配子所进行的多种显微操作和处理技术。包括体外受精、胚胎移植、胚胎分割移植、胚胎干细胞培养等技术。胚胎冷冻技术进一步克服了胚胎移植中母畜周期的时间限制,解决了远距离的运输问题。 相似文献
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动物胚胎生物技术研究进展 总被引：1，自引：0，他引：1
胚胎生物技术是在胚胎移植技术的基础上,对哺乳动物的胚胎进行人为的工程技术操作,然后让它继续发育,获得人们所需要的成体动物的新技术.主要包括:超数排卵、卵母细胞体外成熟培养、体外受精、胚胎移植、胚胎冷冻保存、性别控制、胚胎克隆等一系列 有关胚胎体外操作和改造的技术.本文就这些技术的发展及其应用作一综述. 相似文献
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近年来胚胎工程技术发展迅速,并逐步在畜牧业中推广应用.胚胎移植是目前应用最为广泛的现代繁育技术.经过几十年的发展,国内的胚胎移植相关技术已成熟,可以以多种形式满足不同市场的需求.同时,由于中国奶牛的品质较差,奶业基础相对薄弱,需大力繁育高产优质奶牛,在减少饲养数量的同时提高奶产量,提高饲养经济效益.胚胎工程技术对发展国内奶业意义重大.利用胚胎工程技术提高我国奶产量已具备条件,而且是必由之路. 相似文献
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胚胎移植是指将母畜体内的早期胚胎通过物理方法取出,移植到同种生理状态相同的母畜体内,使之继续发育成新个体的过程。胚胎移植技术在20世纪80年代逐步开始在畜牧生产中应用,随着胚胎冷冻技术的成熟,使国家间通过胚胎实现种畜进出口成为可能。种公牛站选择和培育种公牛的主要途径 相似文献
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胚胎移植技术通过同期发情、超数排卵和人工技术在良种母牛(供体牛)体内生产多枚胚胎,并将早期的胚胎从供体牛取出来移植到另一头母牛(受体牛)胚胎移植技术是加快牛群改良和纯种快速繁育一种重要手段。胚胎质量和数量是影响胚胎移植技术效果的关键因素。 相似文献
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胚胎工程技术在畜牧业上的应用 总被引：1，自引：0，他引：1
胚胎工程或叫胚胎技术 ,是以胚胎移植为基础 ,以转基因动物为中心 ,通过人工操作胚胎 ,定向改变动物性状使之为人类造福的一系列生物技术的总称。主要包括 :胚胎移植、体外胚胎生产 (体外成熟、体外受精和胚胎培养 )、胚胎冷冻、胚胎分割、动物克隆、胚胎性别鉴定、胚胎嵌合、显微受精和转基因动物技术等。1 目前可以在畜牧业上应用的技术胚胎移植、体外胚胎生产 (体外成熟、体外受精和胚胎培养、胚胎冷冻 )、胚胎分割等胚胎工程技术在国外已经商业化 ,牛和羊的胚胎移植技术在我省的畜牧业上的应用前景最大。要开展胚胎移植技术 ,还需要开… 相似文献
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动物胚胎生物技术的研究进展与应用前景 总被引：1，自引：0，他引：1
胚胎生物技术是在胚胎移植技术的基础上，以胚胎为研究对象，经过20多年的试验研究而迅速发展和成熟起来的技术，主要包括：超数排卵、卵母细胞体外培养成熟、体外受精、胚胎移植、胚胎冷冻保存、胚胎性别鉴定和性别控制、胚胎克隆、体细胞克隆和基因转移等一系列有关胚胎的生产、操作和改造的技术。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献