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.     

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.     

Simple and High Performance Timing Synchronization in OFDM System

One ML timing offset estimation method for orthogonal frequency-division multiplexing(OFDM) systems is presented.The performance of our timing offset estimator are compared to that of H.Minn's estimator in terms of estimator variance error in both AWGN channel and multipath fading channel. Because no performance floor exists under high SNR condition,the new estimator can get more accurate estimation result with low computational complexity even under multipath fading environment.     

绵羊EYA3基因表达及其多态性与季节性发情之间的关系

为探究绵羊EYA3基因表达及其多态性与季节性发情之间的关系,本实验通过采用实时荧光定量PCR(qPCR)检测EYA3基因在常年发情绵羊(小尾寒羊)和季节性发情绵羊(苏尼特羊)的大脑、下丘脑和垂体组织中的表达情况,同时利用Sequenom MassARRAY~?SNP技术检测2组绵羊(常年发情组:小尾寒羊、策勒黑羊和湖羊;季节性发情组:滩羊、苏尼特羊和草原型藏羊)EYA3基因SNP位点(g.238191128G>C)的多态性,并与绵羊季节性发情性状进行关联分析。结果表明:无论在小尾寒羊还是苏尼特羊,EYA3基因在各组织中均广泛表达,在苏尼特羊垂体中表达较高(P<0.01);且长光照条件下季节性发情的苏尼特羊垂体中EYA3基因表达量显著高于小尾寒羊(P<0.01)。绵羊EYA3基因g.238191128G>C位点均存在GG、GC和CC3种基因型。g.238191128G>C位点在小尾寒羊、湖羊、策勒黑羊、滩羊、苏尼特羊和草原型藏羊中表现为低度多态(PIC<0.25);在小尾寒羊、策勒黑羊、滩羊、苏尼特羊和草原型藏羊5个群体中均处于哈代温伯格平衡状态(P>0.05);并且该位点基因型频率和等位基因频率在常年发情和季节性发情绵羊组间差异均达到极显著水平(P<0.01)。综上,EYA3基因表达与g.238191128G>C位点与绵羊季节性发情性状存在一定关联。     

Effect of environmental factors on estrus synchronization and artificial insemination success in farmers flock in sheep under semi-arid tropical region

Environmental cues in the different seasons might influence the estrus and lambing percentages. The present study was conducted to assess the effect of environmental factors on estrus synchronization (ES) and artificial insemination success in sheep . During the period from 2012 to 2017, a total of 1,197 ewes of Kheri and Malpura breeds of 34 farms originating from 10 villages were synchronized for estrus and then fixed-time artificial insemination (FTAI) was done. Oestrous synchronization was done by intravaginal progesterone sponges and eCG protocol. Fixed-time cervical insemination was performed 48 and 56 hr after sponge removal in ewes exhibiting estrus, using liquid chilled semen containing 100 million sperm per dose of Patanwadi/Malpura rams. Mean sunshine hours, maximum and minimum ambient temperatures, temperature amplitude, mean relative humidity (RH), temperature-humidity index (THI), mean temperature during sponge-in to sponge-out—12-day period, sponge-out and next day, AI day and AI to next 15 days have been calculated. The estrus response and lambing percentage were higher (p < .05) when ES and FTAI were done during hot-humid with rainfall season. Successful (p < .05) ES occur when the minimum temperature was higher in cold-humid season, and the sunshine hour was higher in hot-humid with scanty rainfall season during sponge-in to sponge-out period. The success of the lambing percentage was higher (p < .05) when maximum temperature, minimum temperature, mean temperature and THI was higher on the day of AI and the next 15-day period, irrespective of the season. The success of FTAI indicates the adaptability of the local breed to tolerate the harsh climate of the hot semi-arid region without much hindrance in lambing percentages.     

Anti-Mullerian hormone and its relationship to ovulation response and fertility in timed AI Bos indicus heifers

This study evaluated the association between plasma anti-Mullerian hormone (AMH) concentration and fertility in Nelore (Bos indicus) heifers submitted to timed artificial insemination (TAI). At the onset of the synchronization protocol, heifers (n = 289) received a subcutaneous P4 ear implant (3 mg) and 2 mg of oestradiol benzoate. Eight days later, the P4 implant was removed and 0.5 mg of oestradiol cypionate, prostaglandin (0.265 mg, i.m.) and equine chorionic gonadotropin (300 UI, i.m.) was administered, and TAI was performed 48 hr after ear implant removal. Ovarian ultrasound evaluations were performed to measure number of ovarian follicles, dominant follicle size and ovulation response. Pregnancy diagnosis was performed by ultrasound 30 days after AI. Heifers with greater circulating AMH had more antral follicles, a smaller dominant follicle near timed ovulation and lower ovulation response to the timed AI protocol compared to heifers with lower circulating AMH. Although AMH and pregnancy outcome had a quadratic-shaped pattern, AMH was not significantly associated with fertility. In conclusion, heifers with lower AMH had larger follicles towards the end of the synchronization protocol and greater ovulation responses, whereas greater circulating AMH was unrelated to conception success.     

杂交水稻超高产制种的技术关键

阐明了杂交水稻超高产制种关键技术 :(1)安排母本比父本早 2天抽穗以充分利用父本初散花粉 ;(2 )利用药物刺激剑叶叶枕分生组织 ,创造最佳授粉态势 ;(3)利用柱头外露敏感期进行特殊技术处理 ,提高母本柱头外露率及柱头外露体积 ;(4 )在父本散粉高峰期人工辅助授粉以及创造超高产制种父母本苗架     

液压四同步马达在举升同步机构中的应用

四同步马达在液压系统中用于同步控制,其控制精度要比其它调速方式高得多。基于此,文章对液压四同步马达和举升机构的工作原理进行了分析,通过介绍液压同步马达的结构分类和特点,以公司YCNH3166垃圾中转站液压系统的4流同步马达为对象,详细阐述了其同步功能的具体实现方法以及影响液压四同步马达同步误差的主要因素和解决方法。