共查询到20条相似文献,搜索用时 781 毫秒
1.
为提高胚胎移植妊娠率,对影响移植妊娠率的受体品种、年龄、胎次、体况、黄体位置等因素进行试验。结果表明:初选合格率平均为49.50%,西+本牛初检合格率显著高于其他4个品种(本地牛,安×本牛,利×本牛,荷×本牛)(P0.05);发情率平均为88.17%,安+本牛高于其他4个品种,但各品种间差异不显著(P0.05);移植利用率平均为68.38%,妊娠率平均为46.8%,西+本牛移植利用率和移植妊娠率高于其他4个品种,但各品种间差异不显著(P0.05)。6~9周岁受体牛初选合格率显著低于2.5~6周岁和2.5周岁以下受体牛(P0.05),2.5~6周岁的受体牛在发情率、移植利用率和移植妊娠率高于6周岁的受体牛和2.5周岁以下的受体牛,但各组间差异不显著(P0.05)。5胎以上受体牛初选合格率显著低于0胎(育成牛)、1~4胎受体牛(P0.05);发情率、移植利用率和移植妊娠率1~4胎受体牛高于0胎(育成牛)和5胎以上受体牛,但各组间差异不显著(P0.05)。上等膘情受体牛发情率显著低于中上和中下等膘情受体牛(P0.05);移植利用率和妊娠率上等膘情受体牛最高,但与中上及中下膘情受体牛差异不显著(P0.05)。卵巢左、右有黄体侧移植妊娠率分别为48.48%、45.85%,两组间无显著性差异(P0.05)。 相似文献
2.
影响受体牛冷冻移植胚胎效果的主要因素 总被引:3,自引:0,他引:3
试验研究影响受体牛移植冷冻胚胎效果的主要因素,目的是解决胚胎移植产业化中容易出现的技术问题,以提高牛胚胎移植妊娠率。在季节、饲养管理、同期发情处理和胚胎移植技术以及环境条件等基本相同的情况下,结果表明:西门塔尔杂交牛的移植利用率和移植妊娠率高于黄牛杂交牛和黑白花奶牛,但各组间无显著性差异(P>0.05);2~6周岁的受体牛移植利用率和移植妊娠率高于7周岁以上和2周岁以下的受体牛,但各组间无显著性差异(P>0.05);经产1~3胎受体牛移植利用率显著高于4胎以上的受体牛(P<0.05),而移植妊娠率则无显著性差异(P>0.05);体况上等与中等的受体牛移植利用率和移植妊娠率无显著性差异(P>0.05);同期发情处理时卵巢处于黄体期的移植利用率显著高于卵泡期,差异极显著(P<0.01);左侧卵巢有黄体的子宫角胚胎移植妊娠率显著高于右侧(P<0.05);胚龄对胚胎移植妊娠率高低依次为早期囊胚、桑椹胚和囊胚,但无显著性差异(P>0.05)。 相似文献
3.
本文从胚胎、受体、受体母牛与胚胎供体间的同期化等方面对影响牛胚胎移植妊娠率的主要因素进行综述,并结合在胚移研究和和推广过程中的体会提出提高妊娠率的技术措施. 相似文献
4.
5.
用地方黄牛做受体,繁殖纯种奶牛和肉牛,是加快牛胚胎移植产业化进程的主要途径。目前,牛胚胎移植技术在我国正处于推广应用阶段,其技术操作程序已逐渐成熟,在小规模应用中的移植成功率已达畜牧业发达国家水平。但在大规模生产中,由于地方黄牛饲养技术落后,其生存条件和营养水平又各有差异,母牛体况和繁殖性能普遍较差,以至移植成功的总体效率较低。因此,改善和提高母牛的体况和繁殖性能,以提供足够合适的个体作受体,对提高牛胚胎移植率有着极其重要的意义。笔者通过对贵州本地黄牛进行胚胎移植的生产实践结果表明,采取补饲、净化生殖道、利用激素处理及加强受体牛移植后饲养管理的技术措施能显著提高农养黄母牛受体利用率和移植妊娠率。 相似文献
6.
7.
<正> 1987年8月21日至9月11日于甘肃省临泽牛场进行了102例牛胚胎移植试验,报告如下: 材料与方法1.1 牛只供体为黑白花牛25头,西门达尔牛1头。均按饲养标准饲养。受体为本地黄牛,黑黄一代,西黄一代,还有1头犏牛和2头尕力巴牛(公黄牛×母犏牛的女儿)。1.2 超排采胚在发情周期9~13天,用FSH超排,连续4日, 相似文献
8.
用黄牛做受体,繁殖纯种奶牛和肉牛,是加快牛胚胎移植产业化进程的主要途径。目前,牛胚胎移植技术在我国正处于推广应用阶段,其技术操作程序已逐渐成熟,在小规模应用中的移植成功率已达畜牧业发达国家水平。但在大规模生产中,由于地方黄牛饲养技术落后,其生存条件和营养水平又各有差异,母牛体况和繁殖性能普遍较差,以至移植成功的总体效率较低。因此,改善和提高黄母牛的体况和繁殖性能,以提供足够合适的个体作受体,对提高牛胚胎移植率有着极其重要的意义。笔者通过对贵州本地黄牛进行胚胎移植生产实践结果表明,采取补饲,净化生殖道,利用激素处理及加强受体牛移植后饲养管理的技术措施能显著提高农养黄母牛受体利用率和移植妊娠率。 相似文献
9.
[目的]选择不同品种牛,利用同期发情和自然发情后作为受体牛,进行日本和牛冻胚移植研究。[方法]选择奶牛20头和南德温杂种肉牛41头作为受体牛,利用CIDR+PG做人工同期发情处理,发情后的受体牛移植和牛冻胚。统计分析受体牛的同期发情率和移植后的妊娠率。[结果]试验结果表明奶牛和南德温杂种肉牛的受体牛同期发情率分别为90.00%和85.36%,差异显著(P<0.05);在同一牛场场使用不同品种受体牛进行冻胚移植试验结果表明,15头奶牛和27头南德温杂种肉牛受体牛妊娠率分别为46.67%和48.14%,差异不显著(P>0.05)。[结论]只要符合胚胎移植受体牛要求,奶牛和南德温杂种肉牛均可作为和牛胚胎移植受体牛。 相似文献
10.
近年来,胚胎移植技术在我国发展迅速,并在生产中得到了一定的应用,但由于费用比较高,且移植成功率受到很多因素影响,使其推广受到了很大限制。本文就牛胚胎移植过程中影响其移植成功率的几个方面因素,包括供体和受体牛的选择、供体和受体牛的同期发情程度、胚胎质量、移植者的技术操作水平、受体牛的饲养管理以及移植季节等作一综述。 相似文献
11.
12.
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
13.
14.
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
15.
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
16.
17.
18.
19.
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
20.
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