胆固醇对山羊精液冷冻效果的影响

研究了胆固醇对山羊精液冷冻的影响。结果表明，胆固醇不影响冷冻后精子的活力，但影响精子的项体，添加胆固醇后，精子顶体部分脱落的比例增高，但全部脱落的比例降低。     

奶牛人工授精受胎率的影响因素与提高方法

1影响因素 应用冷冻精液进行人工授精时,由于运输、保存可能造成缺氮,出现2次冷冻等因素使精液活力降低,甚至死亡。因此,必须确认精液品质,镜检精子的活力和数量是否达标,还要考虑这头种公牛精子与其配种母牛的抗原性。     

牛细管精液冷冻温度曲线的研究

牛冷冻精液精子复苏率的高低与原精质量、精子耐冻性、稀释液种类、稀释方法及精液冷冻和解冻速度等因素有关。其中，精液在冷冻过程中温度变化曲线是影响精子复苏率高低的重要因素之一。研究细管精液在不同条件下冷冻，精液温度变化曲线及精子复苏率变化的规律，优选出细管精液最适宜的冷冻温度曲线，可以为提高牛冷冻精液质量提供重要保障。     

兔子精液冷冻保存综述

精子在冷冻保存过程中会受到不可逆的冷冻损伤或者部分功能改变,因此精子的冷冻保存是一个大挑战。虽然从广义上讲,物种之间的精子冷冻保存是非常相似的,但是每个物种的精子有着各自的特殊性,迫使研究人员不断优化冷冻保护剂和操作程序以更好地适应其特殊性。对家兔精液冷冻保存的概况进行了阐述,讨论了家兔精液冷冻保存的研究概况以及影响冷冻精液和人工授精的因素。     

牛精液冷冻技术应用研究进展

在简要介绍牛精液冷冻技术发展历史的基础上,分析了牛冷冻精液的现状和影响牛冷冻精液受胎率的主要因素,指出了我国牛冷冻精液存在的问题,应加强精液冷冻机理、精液冷冻保护剂、精子质量评估和分离精子的冷冻保存等方面的研究,最后展望了牛冷冻精液的发展前景。     

影响马冷冻精液品质的因素

冷冻运输精液在马育种上的应用已有20年的时间.人工授精技术大大促进了马的育种工作.但是也出现了一些问题,其中最突出的一个问题是,不是所有的种马都适合应用冷冻精液繁殖,因为当某些种畜的精液被处理、冷冻和运输后,其授精能力会下降.2000年,Brinsko等研究认为这一问题可能主要与精浆成分相关[1].冷冻精液维持授精能力的时间一般为24～48小时.超过了这个时间之后,受胎率急剧下降.新的稀释液配方通常宣称能更长时间地维持精子的授精能力,但是在通过改进稀释液配方和精液处理程序来延长精子寿命方面到目前还没有什么突破.近几年,在冷冻技术上出现的一些新的观点为克服和解决部分问题提供了可能.该文主要介绍在精液采集和冷冻阶段影响种马精液质量的一些因素及马精液冷冻技术的发展现状.     

牛精子冷冻损伤及其改善方法

牛精液冷冻与人工授精技术相结合，在牛品种改良、保护优良种质资源中发挥着重要作用。尽管冷冻后部分牛精子活力高达60%以上，但是冷冻后精子受损现象却普遍存在，尤其是受精能力与鲜精相比显著降低。作者详细介绍了冷冻-解冻过程对牛精子造成的主要损伤，包括精子的形态完整性、活力及遗传物质的改变等；阐述了冷冻造成精子损伤的主要原因，即细胞内冰晶形成和氧化应激反应及其产生的可能机制；并且对目前常用的提高冷冻精子质量的方法，如添加冷冻保护剂、优化冷冻程序以及添加抗氧化剂等进行了详细地综述；提出了在冷冻精液研究方面值得探索的问题，以期为家畜精液冷冻保存技术的进一步优化提供理论依据。     

影响猪冻精质量因素的研究进展

精液冷冻保存作为精液长期保存的最佳方法,具有保存时间长、生产成本低等优点,但由于猪精子较其他物种更容易受到低温的损伤,导致猪精液冷冻后精子活力低、受精率低,从而限制了冻精在养猪生产中的广泛使用。为优化猪精液冷冻-解冻方法,提高猪冻精质量,本文基于猪精液冷冻保存的损伤机理,从冷冻前处理、精液稀释液、冷冻和解冻程序等方面对影响猪精液冷冻质量的因素进行了详细阐述和总结。     

维生素B12、E和C在家畜精液保存中的应用

家畜精液保存时,向稀释液中添加一定量的维生素B12、E或C,在提高精液品质方面具有重要的作用。精液稀释液中添加维生素B12,具有维持精子顶体完整率,延长精子体外存活时间和提高解冻后的精子活力的作用。维生素E是重要的抗氧化剂,能通过抑制自由基的形成,阻止诱发的膜脂质发生过氧化,从而维持精子顶体膜的完整,提高精子顶体完整率和降低精子畸形率;维生素E还能防止精子发生冷休克,提高冻精解冻后的精子活力,从而提高受精率。维生素C作为抗氧化物质,能有效地防止冷冻精子磷脂发生过氧化,提高解冻后的精子活力,延长精子在体外存活的时间;维生素C的抗氧化作用还表现在能够保护精子细胞中的遗传基因DNA免受氧化破坏。     

抗氧化剂对家畜精液冷冻保存的应用研究进展

 在家畜精液冷冻稀释液中加入抗氧化剂以提高冷冻精液质量的研究受到广泛关注,通过添加抗氧化剂降低精子在冷冻保存过程中的氧化损伤,保护精子质膜、精子顶体和DNA的完整性,提高冷冻-解冻后精子的受精能力。论文针对目前主要的一些抗氧化剂在家畜精液上应用研究的现状,对精子氧化损伤机理和常用抗氧化剂研究进行综述,期望对家畜精液冷冻保存的相关研究提供一定的理论依据和参考。     

Immunolocalization of the Cholesterol Transporters ABCA1 and ABCG1 in Canine Reproductive Tract Tissues and Spermatozoa

The mammalian sperm membrane undergoes cholesterol efflux during maturation and fertilization. Although ATP‐binding cassette (ABC) transporters are known to transport cholesterol through cell membranes in other organs, their presence in canine testis, epididymis and sperm has not been proven to date. Hence, the aim of the present study was to localize the ABC transporters ABCA1 and ABCG1 in canine testicular and epididymidal tissue as well as in spermatozoa membranes. To this end, semen samples from 12 dogs as well as testicles and epididymides of four young and healthy dogs were prepared for immunohistochemistry, respectively. Capacitation and acrosome reaction (AR) were induced in aliquots of the semen samples before immunostaining to assess changes in the expression of ABCA1 and ABCG1. Evaluation by confocal microscopy revealed the presence of both ABCA1 and ABCG1 in canine testicles and of ABCA1 in the epididymides. In spermatozoa, only ABCA1 immunoreactivity was detected, mainly in the region of the acrosome and midpiece. After induction of capacitation, ABCA1 signal persisted in the acrosome but disappeared after AR, indicating a loss of ABCA1 with the loss of the acrosome. We conclude that ABCA1 and ABCG1 are expressed in canine testis, whereas only ABCA1 is expressed in epididymis and spermatozoa membrane, both transporters probably contributing to the regulation of membrane cholesterol content.     

复合添加剂对解冻后奶牛性控冻精质量及受胎率的影响

【目的】试验旨在研究以褪黑素和地诺前列腺素组成的复合添加剂对奶牛性控冻精解冻后精子质量及奶牛人工授精后受胎率的影响。【方法】30份奶牛性控冻精样均分为2组：试验组和对照组,试验组添加由24 ng/mL褪黑素、1.5 mg/mL地诺前列腺素及精液稀释液组成的250 μL复合添加剂,对照组添加250 μL精液稀释液,试验组和对照组均与解冻后的奶牛性控冻精按照1∶1（V/V）进行混合,室温孵育0、2及4 h,通过免疫荧光染色分析精子活率、顶体完整率、高能线粒体活性精子比率;对216头青年奶牛和82头头胎奶牛输精后通过28 d早孕检测来确定受胎率情况。【结果】与对照组相比,经复合添加剂处理0 h的性控冻精活率、顶体完整率及高能线粒体活性精子比率均无显著变化（P＞0.05）;经复合添加剂处理2 h的性控冻精活率、顶体完整率、高能线粒体活性精子比率均显著升高（P＜0.05）;经复合添加剂处理4 h的性控冻精活率和顶体完整率均无显著变化（P＞0.05）,高能线粒体活性精子比率显著升高（P＜0.05）。在输精试验中,试验组青年奶牛和头胎奶牛中的受胎率分别为65.22%和48.21%,均显著高于对照组（P＜0.05）。【结论】以褪黑素和地诺前列腺素组成的复合添加剂可以促进解冻后奶牛性控冻精精液品质以及青年奶牛和头胎奶牛输精后的受胎率。     

Studies on the Effect of Supplementing Boar Semen Cryopreservation Media with Different Avian Egg Yolk Types on in Vitro Post-thaw Sperm Quality

Fertility after insemination of cryopreserved boar semen is currently below that of fresh semen. In an attempt to improve the post-thaw motility and acrosome integrity of boar sperm, semen was frozen using an adapted Westendorf method in which the chicken egg yolk was replaced by either duck or quail egg yolk. The different composition of the yolk types, particularly the amount of cholesterol, fatty acids and phospholipids, were thought to potentially afford a greater level of protection to sperm against damage during freezing and thawing. Sperm frozen in medium containing chicken egg yolk displayed higher motility immediately after thawing, but there was no difference in the motility of sperm frozen with different types of egg yolk 3 or 6 h after thawing and maintenance at 37 degrees C. Sperm frozen in media containing chicken or duck egg yolk had a higher proportion of intact acrosomes immediately after thawing than sperm frozen in medium containing quail egg yolk, but 6 h after thawing and maintenance at 37 degrees C the sperm that had been frozen in medium containing chicken egg yolk had a higher proportion of intact acrosomes than the sperm frozen in media containing duck or quail egg yolk. Analysis of the composition of the different yolk types showed that the basic components of the yolks were similar, but the ratios of fatty acids and phospholipid classes differed. Duck egg yolk had more monounsaturated fatty acids (MUFA) than chicken egg yolk, which had more MUFA than quail egg yolk. Duck egg yolk contained more phosphotidylinositol (PI) than chicken or quail egg yolks and quail egg yolk contained more phosphotidylserine than either chicken or duck egg yolks. The differences in post-thaw motility and acrosome integrity of boar sperm when frozen in media containing the different types of egg yolk may be due to the variation in composition.     

The Effect of 2-Hydroxypropyl-β-Cyclodextrin on Post-Thaw Parameters of Cryopreserved Jack and Stallion Semen

Cyclodextrins improve post-thaw viability and motility of semen as well as mediate cholesterol efflux and subsequent acrosome reaction in spermatozoa from several species. The objectives of this study were: (a) to assess the effect of prefreeze addition of 60 mM hydroxypropyl-β-cyclodextrin (β-CD) on post-thaw viability and motility of jack and stallion semen cryopreserved in ethylene glycol-based freezing extenders containing 5% or 20% (v/v) egg yolk (LEY and HEY, respectively), and (b) to evaluate the ability of 1 μM calcium ionophore A23187 and/or 60 mM β-CD to induce acrosome reaction in thawed jack and stallion spermatozoa. Post-thaw motility of spermatozoa cryopreserved in HEY was higher (P < .05) for jack but lower (P < .05) for stallion spermatozoa when compared with LEY. Jack and stallion spermatozoa both exhibited higher (P < .05) motility when cryopreserved in 60 mM β-CD than without β-CD. Curvilinear velocity was faster (P < .05) for jack and stallion spermatozoa cryopreserved in LEY than in HEY. A treatment × time interaction affected (P < .05) the proportion of spermatozoa that underwent acrosome reaction. Post-thaw incubation of jack and stallion spermatozoa with β-CD for 90 minutes induced acrosome reaction in 85% and 22% of viable sperm cells, respectively; however, only 32% of jack and 8% of stallion spermatozoa incubated with calcium ionophore underwent acrosome reaction. This study is the first to evaluate the effect of β-CD (not loaded with cholesterol) on jack semen cryopreservation, and results reveal that β-CD may be a useful tool to enhance semen cryopreservation and to induce post-thaw acrosome reaction in jack spermatozoa.     

3种稀释液对乐至黑山羊精液品质的影响

旨在评价不同种类稀释液对乐至黑山羊精液品质的影响。配制柠檬酸-Tris（1号）、磷酸盐（2号）和OviXcell（3号）3种稀释液,采集8只乐至黑山羊新鲜精液,采用上述稀释液进行冷冻保存;测定并比较添加不同稀释液冷冻保存的山羊精液在采集后、平衡后以及解冻后的精子活力、精子畸形率、精子顶体完整率。结果表明：在3种稀释液中,添加OviXcell稀释液（3号）的精液其解冻后精子活力和顶体完整率均最高,精子畸形率最低。提示OviXcell稀释液更适用于乐至黑山羊精液的体外冷冻保存。     

温度与稀释液pH对猪精液常温保存效果的影响

 为提高猪精液常温保存的效果,研究不同温度和稀释液pH对猪精液常温保存效果的影响。结果表明：（1）当精子活力分别为50％和30％时,配方Ⅰ与Ⅱ稀释液保存的精液,在温度为15~20 ℃条件下的精子存活时间均显著高于21~25 ℃（P<0.05）;在pH为6.5~6.9条件下的精子存活时间均显著高于6.0~6.4（P<0.05）;（2）精子顶体染色结果表明,适宜温度与pH条件下,精液保存48 h后,顶体完整率达到96%以上。研究结果表明,猪精液常温保存适宜温度为15~20 ℃,适宜PH为6.5~6.9。     

不同浓度大豆卵磷脂替代蛋黄对东佛里生奶绵羊精液冷冻保存效果的影响

本试验皆在研究添加不同浓度大豆卵磷脂（SL）冷冻保存东佛里生奶绵羊精液的效果。我们在Tris基础稀释液中,添加18%蛋黄为对照组,添加0.5%、1%、1.5%、2%、2.5%SL设为试验组,检测冷冻精液解冻后的精子活率和顶体完整率。结果显示,添加0.5%、2.5% SL冷冻稀释液稀释的精液,解冻后精子活率和顶体完整率与其他组之间存在显著差异（P<0.05）;添加18%蛋黄和1%～2% SL冷冻稀释液稀释的精液,冷冻解冻后精子活率和顶体完整率之间无显著差异（P>0.05）;添加18%蛋黄和1.0%～1.5% SL冷冻稀释液稀释后的精液,进行人工授精后母羊的妊娠率与对照组无显著差异（P>0.05）。因此,大豆卵磷脂可以作为冷冻保护剂用于东佛里生奶绵羊精液的冷冻保存,其最佳添加浓度为1～2%（g／L）。     

不同稀释液对藏猪精液4℃保存效果的影响

为探讨不同精液稀释液对4℃保存藏猪精液的效果,保证优良藏猪种公猪精液的合理、高效利用,该试验选用5种常用的猪精液常温保存稀释液,并在藏猪精液4℃保存至第5天时检查藏猪精子活力、精子畸形率、精子顶体完整率、精子质膜完整率等。结果表明,在精液保存过程中,2号液对藏猪精液的保存效果最佳,精子活力在保存至第5天时仍然保持在0.54,且藏猪精子活力、精子畸形率、精子顶体完整率、精子质膜完整率均高于其余4组（P〈0.05）。该试验研究初步筛选了4℃保存藏猪精液的稀释液,为今后藏猪精液的生产应用奠定了基础。     

奶牛性控精液品质检测及效果分析

本试验旨在利用精子分析仪对奶牛性控冷冻精液精子的运动性能及体外受精率进行分析。结果表明:性控精液精子活力及顶体完整率、前向性与常规精液相比差异显著(P<0.05);曲线速度、直线速度、平均路径速度、平均移动角度、前向性差异均不显著(P>0.05);体外受精率差异不显著(P>0.05)。结论:奶牛性控精液运动性能及受精率低于常规精液。     

Evaluation of Spermatological Parameters Used to Predict the Fertility of Frozen Bull Semen

Kjxstad, H., E. Ropstad and K. Andersen Berg: Evaluation of spermatological parameters used to predict the fertility of frozen bull semen. Acta vet. scand. 1993,34,299-303.– Post-thaw motility, velocity and acrosome integrity of frozen semen were determined in 18 bulls with varying fertility (average non-return rates: 71.3 (± 2.8) - range: 65.2-75.7). Five semen straws were investigated from each bull. The average values for sperm motility (percentage motile spermatozoa), sperm velocity (graded from 0-3) and acrosome integrity (proportion of spermatozoa with intact acrosome) were 67.5%, 2.5 and 79.3%, respectively. Significant correlations were found between sperm motility and velocity, but not between sperm motility and acrosome integrity. Both sperm motility and velocity were significantly related to bull fertility. It was concluded that of the post-thaw semen characteristics investigated in this study these 2 parameters provided a reliable basis for prediction of bull fertility.