无角道塞特羊胚胎移植技术研究

（西北农林科技大学生物工程研究所,陕西杨凌712100）     

使用PMSG、HCG调节繁殖末期母蓝狐发情和产仔效果的试验研究

为了提高乏情母狐的利用率,第1年对50只没有发情表现的青年母蓝狐同时一次注射PMSG200IU/只,5d后再注射HCG100IU/只,有42只出现明显发情症状并接受公狐爬跨,发情率84%。对发情母狐实施子宫内输精,结果无一产仔;第2年对50只非典型发情的青年母蓝狐同时一次注射PMSG200IU/只,5d后再注射HCG100IU/只,全部出现明显的发情症状并接受交配。对其实施子宫内输精3次,结果有24只产仔,产仔率48%。试验结果表明,在母狐繁殖末期,联合使用PMSG和HCG对没有发情表现的青年母蓝狐有促使其发情的作用,但不能使其产仔;对有发情表现但不明显的青年母蓝狐有促进其发情并能使其部分怀孕和产仔的作用。     

农产品电子商务系统分布式数据库的设计

分析了我国农产品数据分散、难以共享的现状,介绍了分布式数据库的结构,详细叙述了分布式数据库的设计内容,提出了农产品电子商务系统中的分布式数据库的设计方案,包括数据分割、数据冗余和数据同步等问题的解决。     

母猪情期启动营养调控分子机制的探讨

养猪生产中后备母猪年更新率高达40％～50％,哺乳母猪断奶后情期启动失败被淘汰比例占30％～40％,50％的母猪终身仅提供30～40头断奶仔猪就被淘汰,给养猪生产带来巨大经济损失.大量研究表明,下丘脑Kisspeptin信号系统在调控雌性动物情期启动和卵泡发育方面发挥重要作用.本课题组前期研究证实,猪的情期启动只有在营养充足、机体处于合成代谢时才能发生和维持.营养是推动后备母猪由生长向繁殖转换,或断奶母猪由泌乳向繁殖转换的物质基础.本文提出了营养调控母猪情期启动的几种理论假设,综述了能量、蛋白质(氨基酸)、维生素D3和部分矿物元素对机体代谢和下丘脑Kisspeptin信号的影响及其在调控母猪情期启动方面的分子机制.     

Effects of syncrhonization between silk receptivity and pollen grain vigor on kernel sets of corn (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

Kernel sets in corn were affected by silk receptivity, pollen grain vigor, and the synchronization of silking and pollen shedding. Grain yield decrement was often caused by poor kernel set ability under field conditions. This study was conducted with two corn hybrids—Yedan 12 and Yedan 19—in both field and laboratory to observe silk receptivity, pollen vigor, synchronization of silking and pollen, and their effects on the kernel sets. The results showed that silk receptivity could be maintained over a relatively longer period of time after silks emerged, but both kernel set percentage and kernel weight decreased as silks aged when pollination occurred. Pollen grains that shed earlier had higher TTC-dehydrogenase activity, higher germination percentage, more rapid pollen tube growth rate, and higher percentage of kernel sets and kernel weight than those that shed later. The effect of delayed silking on kernel set ability was more significant compared with delayed pollen. Synchronization of silking and pollen shedding showed different characters in different hybrids: “partial overlapped” for Yedan 12 and “overlapped” for Yedan 19.     

季节对山羊同期发情处理效果的影响

将316只经产空怀母羊分成4组,分别在春季、夏季、秋季和冬季用孕激素阴道栓结合前列腺素和垂体促滤泡素进行同期发情处理,并在发情结束后剖检部分山羊检查卵巢排卵点与黄体情况.结果表明处理羊只的发情率以秋季最高,为94.74%;与春、夏、冬季相比差异极显著(P＜0.01);以夏季发情率最低,仅为59.55%;春季和冬季发情率分别为72.57%和78.95%,处于中等.山羊剖检结果表明春、夏、秋和冬季分别有4只、4只、14只和10只母羊有经排卵形成的1～2个排卵点(或新生黄体),分别占各季剖检山羊的80.00%,80.00%,87.50%和83.33%.反映季节是影响山羊同期发情处理效果的一个重要因素.     

山羊超数排卵和同期发情研究

用ＦＳＨ（以４种程序注射）配合ＬＨ和前列腺素对安哥拉山羊和奶山羊进行超排处理。结果表明：ＦＳＨ各给予方式的超排效果间没有显著差异（Ｐ＞０．０５）；安哥拉山羊对超排的反应弱于奶山羊（Ｐ＜０．０５）；超排后回收的可用卵母细胞数显著高于可用胚胎数（Ｐ＜０．０１）。１５－甲基ＰＧＦ２α和氯前列烯醇对奶山羊的同期发情率基本一致；但二者从注射到发情的间期具有显著差异（Ｐ＜０．０５）。注射前列腺素的时间显著影响诱导发情效率，对奶山羊而言，在情期的８～１６ｄ内使用，效果确切     

Probability of pregnancy to artificial insemination either after detected oestrus or at a fixed time in dairy cows: Influence of intrinsic and extrinsic factors in a large-scale,on-farm study

The first aim of this study was to determine the influence of the procedures [hormonal treatments for fixed time artificial insemination (FTAI) versus insemination at spontaneous oestrus (SEAI)] on several sequential inseminations (AI). A second aim was to determine the influence of some intrinsic and extrinsic factors and their interactions, including characteristics of the animals such as age, season, farm, sire, and AI technician on the response to both procedures. A retrospective analysis was performed from a data base of 120.807 AIs of healthy cows with at least 40–70 days post-partum at first service. Overall, FTAI achieved slighter greater pregnancy rates than insemination after detected oestrus. The second AI seems to be a key insemination as effects of sire and technician were greater than in the following ones. The use of FTAI or SEAI in one AI did not affect the results of the following AIs, regardless if FTAI or SEAI procedures were used in that AI. Technician had greater variation than sire or farm on final pregnancy rate. The results of each sire for pregnancy rate varied according to the type of insemination, with sires achieving greater results with one or other procedure. Pregnancy rate was positively related to the days in milk in the first two AIs. Results were greater in autumn than in spring services.     

母猪诱导发情及排卵效果研究

研究不同方法对母猪的诱导发情及排卵效果的影响。采用三种处理方法对母猪进行了诱导发情及排卵研究。结果表明，PMSG+HCG组的诱导发情率与情期受胎率均极显著（P﹤0.01）高于三合激素组、显著（P﹤0.05）高于PMSG组，且PMSG组的诱导发情率与情期受胎率均显著（P﹤0.05）高于三合激素组；经PMSG+HCG方法诱导发情处理的母猪，其发情高峰发生在注药后48~96h，母猪发情呈现明显的同期化；PMSG+HCG方法处理母猪后，可以提高母猪的产仔数及活仔数，且对受胎率无影响；进一步观察母猪排卵及胚胎发育状况表明，PMSG+HCG方法对母猪进行诱导发情及排卵并没有影响胚胎的质量，胚胎开始进入子宫的时间发生在母猪配种后60h以前，此时，胚胎处于4细胞期。说明采用促性腺激素对母猪的诱导发情效果要明显好于性腺激素，且采用适宜剂量的PMSG与HCG混合注射来诱导母猪发情及排卵是完全可行的。     

Drive-response Synchronization for Chaotic Systems

In the drive response method of Pecora and Carroll (the PC method), the response system is copied directly from drive system and is steady subsystem of drive system. But sometimes the PC method is disabled. Therefore, another method of realizing the drive response of chaos systems is put forward in this paper. The response system is not copied directly from steady subsystem of drive system, but is constructed from arbitrarily state variable of drive system. At the same time, the driving function is added in the response system, and the method of construction is pointed out. The method can realize the chaos synchronization that can not be realized by PC method.