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《畜牧与兽医》2020,(8)
试验旨在研究影响绵羊胚胎移植妊娠率的关键因素。试验选取64只供体绵羊,对其进行超数排卵处理,同时选取370只受体绵羊,进行同期发情处理。采集胚胎分析其质量、数量及发育阶段,观察受体卵巢黄体数对妊娠率的影响。对试验数据进行卡方检验分析。结果表明,A级桑葚胚妊娠率(72.3%)显著高于B级桑葚胚的妊娠率(60.0%),P0.05;移植1枚A级桑葚胚妊娠率(71.8%)显著低于移植2枚A级桑葚胚妊娠率(82.4%),P0.05;移植1枚B级桑葚胚妊娠率(48.2%)显著低于移植2枚B级桑葚胚妊娠率(58.3%),P0.05;胚胎发育阶段和黄体数对妊娠率无显著性影响(P0.05)。综上所述,胚胎等级、移植胚胎数是影响绵羊胚胎移植妊娠率的主要因素。 相似文献
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[目的]为了评估胚胎质量和发育阶段对奶牛胚胎移植妊娠率的影响。[方法]使用63头青年奶牛作为供体进行超数排卵,评估回收胚胎质量和发育阶段。选择334头青年奶牛作为受体鲜胚移植不同质量和发育阶段胚胎。对胚胎质量分布、发育阶段分布、不同质量胚胎和不同发育阶段胚胎移植30 d妊娠率进行统计分析。[结果]可用胚胎中A级胚胎比例(60.78%)显著高于B级和C级胚胎比例(36.70%和2.52%)(P<0.05);致密桑椹胚比例(54.36%)显著高于早期囊胚,囊胚和扩张囊胚比例(18.35%,25.0%和2.29%)(P<0.05)。A级和B级胚胎移植30 d妊娠率(63.55%和64.35%)显著高于C级胚胎移植30 d妊娠率(44.44%)(P<0.05);致密桑椹胚、早期囊胚、囊胚和扩张囊胚移植30 d妊娠率差异不显著(P<0.05),早期囊胚、囊胚移植30 d妊娠率高于致密桑椹胚、扩张囊胚移植30 d妊娠率(P<0.05)。[结论]选择不同发育阶段的A级和B级胚胎能够获得较高胚胎移植妊娠率,增加早期囊胚和囊胚阶段胚胎移植数量能够提高胚胎移植妊娠率。 相似文献
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统计分析了河北省2007~2009年度胚胎移植妊娠情况。结果表明:1)胚胎级别对妊娠率有显著影响(43.02%∶36.65%,P0.01);2)胚胎不同发育阶段对妊娠率没有显著影响,但早期囊胚妊娠率为44.34%,高于其他组(P0.05);3)胚胎冷冻(59.38%∶50.00%)与胚胎取样(54.69%∶51.35%)对胚胎的妊娠率均有一定的影响,但差异均不显著(P0.05);4)春季和冬季的妊娠率为36.42%和37.74%,显著低于夏季移植妊娠率45.82%(P0.05)与秋季无显著差异(P0.05)。夏季和秋季胚胎移植妊娠率差异不显著(45.82%∶42.60%,P0.05);5)受体牛营养状况对移植妊娠率影响显著(P0.01)。 相似文献
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试验就胚胎的发育阶段、胚胎保存时间及移植胚胎数等因素对胚胎移植效果的影响情况进行了研究.结果表明,胚胎发育日龄对受体妊娠率没有显著影响(P>0.05),但移植8~16细胞的胚胎的妊娠率略高于2~4细胞(58.49% vs 61.47%).人员不是影响受体妊娠率的主要因素.胚胎在体外保存0~120 min对妊娠率没有显著影响,但以在体外保存0~30 min内移植的妊娠率最高(65.61%).黄体与移植胚胎的相对位置对受体的妊娠率没有显著影响(P>0.05),但移植双胚的受体的妊娠率较移植单胚高(61.76% vs 45.17%).同时,试验统计了经胚胎移植产生的羔羊和自然繁殖羔羊之间的差异,发现经胚胎移植产生的波尔山羊母羔的初生重极显著地高于自然繁殖的母羔(P<0.01),但公羔间的初生重以及公、母羔间的体高、体长、胸围、死亡率和性别比例与自然繁殖羔羊差异不显著(P>0.05). 相似文献
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[目的]探讨提高奶牛冷冻胚胎移植妊娠率方法。[方法]对比1次、2次同步发情奶牛冷冻胚胎移植受体母牛的试验妊娠率。[结果]1次、2次同步发情胚胎移植妊娠率分别为44.45%和70.73%。[结论]同步发情对胚胎移植妊娠率有很大影响,2次同步发情可显著提高奶牛冷冻胚胎移植妊娠率。 相似文献
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影响羊胚胎移植妊娠率的因素分析 总被引:2,自引:0,他引:2
本研究对胚胎质量、胚胎移植数量、胚胎发育阶段、冷冻方法、移植方法及饲养管理水平等因素对移植妊娠率的影响进行研究。结果表明:移植胚胎移植数量和妊娠率有显著影响(P<0.05);在冷冻胚胎前后,人为因素、使用设备等均可影响到胚胎的质量,进而影响到移植的妊娠率(P<0.05);经过不同处理方法的胚胎其移植效果差异显著,用程序冷冻法冷冻波尔山羊胚胎移植妊娠率为10.7%(60/560),用EFS40玻璃化冷冻法冷冻胚胎其移植妊娠率为42.9%(60/140);受体的营养状况不同对移植妊娠率起很大作用,从营养状况不好到营养状况良好的受体,其移植妊娠率差异显著;供、受体发情的同期化程度也是决定妊娠率的主要因素,发情同步差在6h内的妊娠率最高(62.3%);受体的重复使用、健康状况和季节等因素均可影响到移植的妊娠率。 相似文献
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波尔山羊胚胎移植影响因素的研究 总被引:1,自引:0,他引:1
试验就胚胎的发育阶段、胚胎保存时间及移植胚胎数等因素对胚胎移植效果的影响情况进行了研究。结果表明,胚胎发育日龄对受体妊娠率没有显著影响(P>0.05),但移植8~16细胞的胚胎的妊娠率略高于2~4细胞(58.49%vs 61.47%)。人员不是影响受体妊娠率的主要因素。胚胎在体外保存0~120min对妊娠率没有显著影响,但以在体外保存0~30 min内移植的妊娠率最高(65.61%)。黄体与移植胚胎的相对位置对受体的妊娠率没有显著影响(P>0.05),但移植双胚的受体的妊娠率较移植单胚高(61.76%vs 45.17%)。同时,试验统计了经胚胎移植产生的羔羊和自然繁殖羔羊之间的差异,发现经胚胎移植产生的波尔山羊母羔的初生重极显著地高于自然繁殖的母羔(P<0.01),但公羔间的初生重以及公、母羔间的体高、体长、胸围、死亡率和性别比例与自然繁殖羔羊差异不显著(P>0.05)。 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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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 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