版纳微型猪近交系精子冷冻保存研究

在版纳微型猪近交系（BMI）公猪精液冷冻保存稀释液中添加不同浓度甘油,并对不同解冻液配方和解冻方法进行研究,对比解冻后的精子活力、质膜完整率和顶体完整率,优化BMI公猪精液冷冻保存方法。结果表明,解冻后,甘油浓度为2%和3%组的精子活力、质膜完整率、顶体完整率显著高于1%、4%和5%组（P<0.05）;Ⅰ号解冻液解冻后精子活力、质膜完整率、顶体完整率均显著高于Ⅱ、Ⅲ和Ⅳ号解冻液（P<0.05）;在活力、质膜完整率和顶体完整率方面,40℃ 6 s和50℃ 6 s这两种程序的解冻效果都显著优于38℃ 30 s（P<0.05）。由此可见,2%或3%的甘油作为抗冻保护剂、Ⅰ号解冻液解冻、40℃ 6 s或50℃ 6 s水浴解冻是较为理想的BMI公猪精液冷冻保存方法。     

不同冷冻保护液和解冻温度对猪精液冷冻效果的影响

在BF5稀释液中分别添加不同水平的牛血清白蛋白(BSA)(0.5,1,1.5 g/L)、二甲基乙酰胺(DMA)(0.5%,1%,1.5%)、甲基-β-环糊精载胆固醇(CLC)(1,2.5,5 g/L),对成年健康猪精液进行冷冻保存,于不同温度(37,50,70℃)解冻后分别检测冷冻后精子的活率、活力、质膜完整性、项体完整率、线粒体活性.结果显示,0.5 g/L BSA组冷冻后精子活力、质膜完整率、顶体完整率和线粒体活性均高于其他组,但差异不显著(P0.05).1% DMA组冷冻后精子活率和活力显著优于1.5%DMA组(P＜0.05),同时也高于对照组(3%甘油)冻后精子活率和活力,但差异不显著.不同质量浓度CLC组冷冻后精子的活率、活力、质膜完整性和线粒体活性与对照组相比差异不显著.50℃和70℃解冻组精子的活率和线粒体活性显著高于37℃解冻组的精子;50℃解冻组精子的活力和质膜完整率显著高于其他2组.因此,在猪精液冷冻稀释液中,用DMA可以代替甘油作为渗透性保护剂,且以1%DMA,50℃解冻最佳.     

不同稀释液配方对奶牛冷冻精液的影响

采用假阴道法采集成年种公牛精液,经精液品质检查后,合格精液用四种不同冷冻稀释液进行稀释、冷冻、以筛选出适宜的冷冻稀释液和最佳冷冻保护剂.结果表明:Ⅱ号稀释液优于其它3种稀释液(P＜0.05);甘油为最佳冷冻保护剂.优于乙二醇和DMSO冷冻效果(P＜0.05),其最佳浓度为7%,精子冷冻后活率平均可达0.45±0.575,畸形率15.44%,项体完整率57.82%;奶牛细管冻精的解冻效果以75℃水浴,2 S到6 S的解冻时间最佳.     

解冻稀释液及孵育温度对冷冻-解冻后犬精液品质的影响

实验旨在比较解冻后解冻稀释液(Tris-柠檬酸-葡萄糖稀释液)的添加比例(1:0、1:1、1:2)对精液品质的影响,并比较了4种孵育温度(37、34、25、4℃)对精子寿命及精子活力的影响,探索合适的冷冻-解冻后犬精液的孵育条件。结果显示:解冻稀释液的添加与否及添加比例对解冻后孵育30 min的精子活力、活率、质膜完整率及顶体完整率均无显著影响;解冻后,在不同温度下孵育30 min,4组精子活率和质膜完整率无显著差异,而4℃孵育温度下精子活力和顶体完整率高于37℃(P0.05);解冻后孵育2 h,4℃孵育温度下的精液品质(精子活率、精子活力、质膜完整率、顶体完整率)最佳(P0.05),34℃和25℃组之间差异不显著,而37℃组的精液品质最差。结果表明,解冻稀释液对解冻后精液的孵育效果无影响,而解冻后精液的孵育温度以4℃最佳。     

冷冻距离和冷冻保护剂种类对超低温保存新西兰兔精液品质的影响

为了探讨新西兰兔精液超低温冷冻保存的最佳方法,试验采集新西兰成年公兔精液,采用0.25 mL细管冷冻法进行超低温冷冻,以解冻后精液活率、质膜完整性、顶体完整率为指标,研究距离液氮面不同高度和冷冻保护剂种类对冷冻保存兔精液品质的影响。结果表明:冷冻精液距离液氮面3 cm,其精液活率、质膜完整性和顶体完整率明显优于1 cm和5 cm;在冷冻稀释液中添加甘油相对于其他冷冻保护剂对精液品质的保护效果好,甘油浓度为3%时相对其他浓度效果较好。说明了距液氮面3 cm冷冻,冷冻稀释液中添加3%甘油对兔精液的保存效果较好。     

新疆驴冷冻精液的研究

试验旨在探究新疆驴冷冻精液的最佳稀释保护液与处理方法。以假阴道采集新疆驴精液,并用5种不同稀释保护液稀释冷冻后,选取其中较为理想的稀释液作为对照组,再通过分别添加4%、5%、6%、8%甘油处理试验,最后再选用添加甘油后冷冻效果最优的稀释液为对照来进行离心浓缩试验。结果表明：①5号稀释液冷冻—解冻精液后,其活力、顶体完整率要显著高于其他4种稀释液（P<0.05）;②以5号稀释液为对照组,添加6%甘油(7号稀释液)冷冻后,精子的活力、顶体完整率要显著高于添加4%、5%、8%甘油组（P<0.05）;③以7号稀释液为对照组,通过离心浓缩,精液在冷冻后其活力和精子顶体完整率都显著提高（P<0.05）。结果提示,将驴精液用6%葡萄糖、2%乳糖、6%甘油为主的稀释液稀释,并经500 r/min离心浓缩10 min处理后,其冷冻效果最好。     

附睾尾液对绵羊精液冷冻保存的影响

实验旨在研究冷冻稀释液中添加附睾尾液（Cauda Epididymal Fluid,CEF）对绵羊精液冷冻保存的影响。利用假阴道法收集4只湖羊精液并混合,以附睾尾液中总蛋白为基准,在冷冻稀释液中分别添加不同浓度CEF(0、140、280、420μg/mL)。精液经过冷冻后投入液氮保存,解冻后检测精子活力、运动参数,以及质膜完整率、顶体完整率、线粒体膜电位、37℃精子存活时间等指标。结果表明：冷冻-解冻后280μg/mL CEF组的精子活力、前向运动、平均路径速度、直线运动速度、直线度、线性度、头部横向位移幅度均显著高于其他各组（P<0.01）,曲线运动速度高于其他各组（P<0.05）;精子质膜完整率、顶体完整率也高于其他各组（P<0.05）;JC-1染色结果显示,280μg/mL CEF组精子线粒体膜电位高于其他各组（P<0.05）;280μg/mLCEF组精子在37℃环境下可存活14h,较对照组精子能多存活4h。可见,在冷冻稀释液中添加适量CEF可以提高精液的冷冻效果。     

不同浓度的甘油和DMSO对蒙古羊精子活力的影响

研究由两个实验组成:实验一探讨添加不同浓度的甘油(1%、3%、5%、7%,V/V)对冷冻精子活率的影响,实验二探讨在37℃或5℃下添加不同浓度的二甲基亚砜(DMSO)(1%、1.25%、1.5%、1.75%,V/V)对冷冻精子活率的影响.通过实验组获得蒙古羊的最优的甘油浓度稀释液条件下,测定精子解冻后的活力、直线运动率、成活率及顶体完整率.同样用DMSO代替甘油测定精子活率、直线动动率、成活率和顶体完整率,实验结果显示前一项指标得到显著的改善(P＜0.05),且在37℃添加7%甘油效果最好.但是顶体完整率随着甘油或DMSO浓度的增加而出现下降趋势,也就是顶体完整率在5℃下添加1%的甘油或1.75%的DMSO效果较好(P＜0.05).实验中在37℃中增加DMSO顶体完整率显著下降(P＜0.05),此外,在5℃时添加1%DMSO时精子顶体完整率优于其他实验组.实验中在37℃条件下加入1.75%的DMSO比在5℃下精子活力好,在37℃添加7%的甘油比在5℃下添加7%的甘油效果显著(P＜0.05).研究结果表明,对于蒙古羊甘油仍是较好的精子冷冻保护剂.     

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）。     

猪精液冷冻技术的研究

以解冻后的精子活率、活力、质膜完整率、顶体完整率和人工授精结果为判定指标 ,比较了几种冷冻稀释液、解冻液及冷冻 -解冻程序对猪精液冷冻的效果 ,并对所筛选出的最佳稀释液和冷冻程序做了改进。结果如下 :(1) 号稀释液冷冻解冻后的精子活力 (32 .4± 7.3) %、活率 (4 2 .2± 3.2 ) %、顶体完整率 (6 2 .3± 0 .8) %和弯尾率 (4 2 .6± 7.5 ) %均显著高于 、 、 号稀释液 (P<0 .0 5 )。 (2 )在 号稀释液中添加 0 .5 %、1%和 2 %的 O.E.P(氨基 -钠 -十二烷硫酸酯 )使精子活率提高 5 %、弯尾率提高 6 %、顶体完整率提高近 10 % ,与对照组相比差异显著 (P<0 .0 5 )。 (3)应用改进的稀释液 ( 液加 1% O.E.P) ,细管法比颗粒法冷冻精子活率提高近 7个百分点 ,活力提高 6个百分点 (P<0 .0 5 )。(4 )室温预平衡 4h的精子活力和活率都比对照组 (0 h)有显著提高 (P<0 .0 5 ) ,而预平衡 2、6 h的精子活力和活率与对照组差异不显著 (P>0 .0 5 )。 (5 ) 号解冻液解冻后精子活力 (4 2 .9± 2 .6 ) %显著高于 、 、 号解冻液 (P<0 .0 5 )。 (6 )用 5 0℃水浴解冻精子的活力 (4 6 .3± 2 .6 ) %显著高于 39℃ (4 2 .9± 2 .6 ) %和 70℃水浴 (4 1.1± 5 .7) %解冻的精子活力 (P<0 .0 5 )。 (7)精清和 号解冻液     

Sperm motility, plasma membrane integrity, and binding capacity to homologous zona pellucida of cryopreserved epididymal spermatozoa in the domestic cat

We examined motility, plasma membrane integrity, and binding capacity to homologous zona pellucidae (ZP) of frozen/thawed epididymal cat sperm as a model species for endangered felines. Epididymal spermatozoa from 20 domestic cats were frozen with freezing egg-yolk extender containing 3.0% glycerol in 0.25-ml straws. Post-thaw motility and plasma membrane integrity of the frozen/thawed spermatozoa were 31.8 +/- 2.4% and 32.2 +/- 4.2%, respectively. The frozen/thawed spermatozoa were co-cultured with frozen/thawed immature homologous oocytes with intact ZP for 3 h to examine their ability to bind to the ZP. Sixteen of the 20 frozen/thawed sperm samples demonstrated the ability to bind to ZP. These results indicated that the freezing system for epididymal sperm used in the present study gives appropriate information for banking the genetic resources of wild felid species.     

Influence of partial or total replacement of glycerol by alternative cryoprotectants in Ghent freezing extender on post‐thaw sperm quality in stallions

Although glycerol is the cryoprotectant most commonly used in stallions, it has also a considerable toxicity for equine sperm. It was the aim of this study to analyse the quality of frozen‐thawed stallion semen after complete or partial replacement of glycerol in the freezing extender by alternative cryoprotectants. We hypothesized that partial or total replacement of glycerol by cryoprotectants occurring in cold‐resistant frog, insect or plant species results in similar or better semen quality after freezing–thawing. As basic medium, the commercial Ghent basic extender was used and either supplemented with glucose and urea, trehalose and proline, or trehalose and betaine. Based on a series of preliminary experiments, semen was frozen in either commercial Ghent cryopreservation extender (Ghent control), Ghent glucose–urea extender or a Ghent combined extender (glucose–urea, trehalose‐betaine and trehalose‐proline; volume ratio of 2:1:2) in a computer‐controlled rate freezer. After freezing–thawing, semen was analysed for motility, membrane integrity, phosphatidylserine translocation, mitochondrial membrane potential and chromatin condensation. No differences between Ghent control and Ghent glucose–urea extender were seen, while all endpoints except DNA integrity were negatively affected in Ghent combined extender (e.g., progressive motility: Ghent 49.2 ± 3.7, Ghent glucose–urea 46.5 ± 4.6, Ghent combined 24.4 ± 2.8%; p < .001). In conclusion, glycerol concentration in a commercial freezing extender for equine spermatozoa can be successfully reduced when urea as an additive cryoprotectant is added and the glucose concentration is elevated. However, total glycerol replacement with urea, betaine, proline and trehalose was less successful.     

Impact of Ultra‐Rapid Freezing on the Motility,Morphology, Viability and Acrosome Integrity of Epididymal Cat Sperm Diluted in Sucrose‐Based Extenders

The objective of the present study was to investigate the influence of different sucrose‐based extenders on the motility, morphology, viability and acrosomal integrity of epididymal cat spermatozoa cryopreserved by ultra‐rapid freezing method. Nine cats were castrated, and collected semen was diluted 1 : 1 with Dulbecco`s phosphate‐buffered saline‐BSA1%‐based extender supplemented with different sucrose concentrations (0, 0.25, 0.4 and 0.6 m ). After ultra‐rapid freezing, samples were thawed and sperm motility, morphology, viability and acrosome status were assessed. At thawing, the number of progressively motile (p < 0.01) and morphologically normal (p < 0.01) sperm was higher in the sucrose‐supplemented groups than in the sucrose‐free group. Viability of spermatozoa cryopreserved without sucrose was significantly reduced. In extender supplemented with 0.4 m sucrose, spermatozoa viability showed higher values (57.0 ± 4.7; p < 0.01). No significant differences were detected among groups for sperm acrosome integrity. Results support that cat sperm survive after ultra‐rapid freezing using sucrose as a cryoprotectant, and the best results were achieved when 0.4 m of sucrose was used. This is the first report on sperm ultra‐rapid freezing of cat sperm and further studies on extenders, sperm management or cryovials should be carried out to improve sperm cryosurvival.     

Sperm cryopreservation in the Far‐Eastern wildcat (Prionailurus bengalensis euptilurus)

The Far‐Eastern wildcat (Prionailurus bengalensis euptilurus) is a rare and poorly investigated nondomestic felid species. An attempt of freezing and cryopreserving Far‐Eastern wildcat spermatozoa in CaniPlus Freeze (CPF) medium is reported. Sperm was collected by electroejaculation from five adult Far‐Eastern wildcat captive‐born males. Epididymal spermatozoa from five adult randomly bred domestic cat males were used as a reference. The viability of frozen–thawed spermatozoa evaluated by double staining with SYBR Green I and PI followed by the subsequent confocal laser scanning microscopy (CLSM) was 38.2% ± 3.0% for the domestic cat and 38.0% ± 10.2% for the Far‐Eastern wildcat. The motility of frozen–thawed spermatozoa was 30.8% ± 9.8% for the domestic cat and 33.7% ± 15.1% for the Far‐Eastern wildcat. Sperm morphology was assessed by light microscopy. The total percentage of normal spermatozoa after freezing and thawing was 51.9 ± 5.9 for the domestic cat and 55.0% ± 6.4% for the Far‐Eastern wildcat. Defects of flagella were the most frequently observed abnormalities in both species (32.2% ± 4.8% and 30.8% ± 4.4% of all reported anomalies for the domestic cat and Far‐Eastern wildcat, respectively). Domestic cat epididymal and Far‐Eastern ejaculatory spermatozoa fertilized in vitro‐matured oocytes of the domestic cat (30.0% ± 5.5% and 35.5% ± 15.0%, respectively). Taken together, these results suggest that the freezing of Far‐Eastern wildcat spermatozoa with CPF medium is a suitable method for Felidae cryopreservation.     

Comparative study of the effects of various cryoprotectants in preserving the morphology of frozen and thawed fowl spermatozoa

1. The effects of various cryoprotectants (glycerol, dimethyl‐sulphoxide (DMSO), methylformamide and ethylene glycol) of the same molarity on preserving the morphology of frozen and thawed fowl spermatozoa (especially midpiece and acrosome) were examined under the light (LM) and scanning electron microscope (SEM) to determine the most suitable.

2. Under LM, the mean respective increases in sperm deformity in semen diluted with ethylene glycol, methylformamide, glycerol and DMSO were 4·5, 4·9, 5·0 and 6·5 percentage points.

3. Under SEM, the mean respective increases in acrosomal deterioration in semen diluted with glycerol, ethylene glycol, DMSO and methylformamide were 6·6, 8·8, 13·1 and 31·2 percentage points.

4. From these results, it appears that glycerol is superior to ethylene glycol DMSO and methylformamide as a cryoprotectant.

     

Comparison of acetamide and dimethylsulfoxide as cryoprotectants of European brown hare (Lepus europaeus) spermatozoa

The aim of the present study was to assess the effect of dimethylsulfoxide (DMSO) and acetamide on the post-thaw properties of hare semen and to perform an AI trial with frozen-thawed semen. Semen was collected under general anaesthesia by the electroejaculation method from 6 males. Immediately after collection, the semen was diluted with an extender containing the following components: 250 mM Tris, 80 mM citric acid, 70 mM glucose, 1.0 M DMSO, egg yolk (17% v/v) and kanamycin (80 mg/l); this extender was used for Protocol I (n=17). In Protocol II (n=15), the DMSO was replaced with 1.0 M acetamide. Immediately after thawing and after incubation for 90 and 180 min at 37 C, the properties of semen were evaluated by computer-assisted semen analysis, and the percentage of viable, acrosome intact spermatozoa was evaluated using flow cytometry. During the 3-h incubation, the percentages of motile spermatozoa and spermatozoa with progressive motility were significantly higher in Protocol I (P<0.01). Immediately after thawing, path and straight velocity were significantly higher in Protocol I (P<0.01), as was the curvilinear velocity (P<0.05). The amplitude of lateral head displacement was higher after 3-h incubation in Protocol I (P<0.05), and no differences in beat cross frequency were found between Protocol I and II at any incubation time. The percentage of viable, acrosome intact spermatozoa determined with flow cytometry was higher in Protocol I (P<0.01) at all incubation times. As a result of artificial insemination with the semen frozen with DMSO as a cryoprotectant, two out of three inseminated females delivered two healthy young each. Following artificial insemination with the semen frozen with acetamide as a cryoprotectant, two out of three inseminated females delivered one healthy young each. On the basis of the results, it should be stated that DMSO ensures better post-thaw properties of hare spermatozoa than acetamide.     

Trehalose in glycerol-free freezing extender enhances post-thaw survival of boar spermatozoa

Cryopreservation of boar semen is still considered suboptimal due to lower fertility as compared with fresh samples when glycerol, a permeating cryoprotectant, is used. Trehalose is a non-permeable cryoprotectant and nonreducing disaccharide known to stabilize proteins and biologic membranes. The aim of this study was to evaluate the cryosurvival and in vitro penetrability of boar spermatozoa when glycerol was replaced with trehalose in a freezing extender. Ejaculated Berkshire semen samples were diluted in egg yolk-based freezing extender containing glycerol (100 mM) or trehalose (0, 50, 100, 150, 200 and 250 mM) and cryopreserved using a straw freezing procedure. Thawed samples were analyzed for motility, viability, mitochondrial membrane potential (MMP), and acrosome integrity. In experiment 2, penetrability of spermatozoa cryopreserved with 100 mM glycerol or trehalose was examined. Replacement of cryoprotectant glycerol (100 mM) with trehalose had no effect on sperm viability, but replacing it with 100 mM trehalose improved motility, MMP and acrosome integrity significantly. Sperm motility and MMP were considerably higher in 100 mM trehalose, whereas the acrosome integrity was substantially higher in 100–250 mM trehalose. The in vitro penetration rate was also significantly higher in spermatozoa cryopreserved with trehalose (61.3%) than in those cryopreserved with glycerol (43.6%). In conclusion, 100 mM non-permeable trehalose can be used to replace glycerol, a permeating cryoprotectant, for maintenance of better post-thaw quality of boar spermatozoa.     

Effects of Thawing Temperature and Post‐thaw Dilution on the Quality of Cat Spermatozoa

The present study aimed to compare cat sperm quality after thawing using two different temperatures (37 and 70°C) and to investigate the effects of post‐thaw dilution on the sperm quality and longevity of ejaculated cat spermatozoa. Six ejaculates of each of six male cats were collected using an electroejaculator (total 36 ejaculates). The semen was frozen in 0.25‐ml straws using a Tris egg yolk extender containing Equex STM paste. Four straws prepared from each ejaculate were thawed at four different occasions; (i) at 37°C for 15 s, (ii) at 37°C for 15 s and diluted 1 : 2 with Tris buffer (v/v), (iii) at 70°C for 6 s, (iv) at 70°C for 6 s and diluted 1 : 2 with Tris buffer (v/v). The percentages of motile spermatozoa, the scores of progressive motility, the percentages of spermatozoa with intact plasma membrane (using SYBR‐14/EthD‐1 stains) and intact acrosome (using fluorescein isothiocyanate conjugated peanut agglutinin/propidium iodide stains) were evaluated in fresh semen at 0, 2, 4 and 6 h after thawing. The thawing temperature had no effect on any sperm parameters throughout the incubation period (p > 0.05). The dilution after thawing improved sperm motility, progressive motility and acrosome integrity (p < 0.05). The thawing of cat spermatozoa and subsequently diluting with Tris buffer resulted in an immediate (at 0 h) overall (combined over temperature) percentage of motile sperm of 64.8 ± 10.7 (mean ± SD), a score of progressive motility of 4.0 ± 0.5, a percentage of spermatozoa with intact plasma membrane of 64.4 ± 12.1 and intact acrosome of 44.8 ± 20.2. In conclusion, frozen cat semen can be thawed either at 37 or 70°C and post‐thaw dilution is recommended to reduce the toxic effect of some ingredients in the extender during post‐thaw incubation.     

红腹锦鸡精液冷冻稀释液配方的筛选

为加强濒危珍稀动物种质资源的保护,开展了濒危珍稀禽类—红腹锦鸡的人工授精研究。2005年5月26日~6月8日,对8只红腹锦鸡用手按摩其背、尾部采精12次。初测其精液品质,结果表明,采精量平均(0.114±0.016)mL(0.01~0.2 mL),每毫升精液中精子平均3.2亿个(3.0~3.3亿),活力9级以上,pH值6.5,偏酸性,淡乳白色(半透明似冲熟的藕粉),微腥。鲜精分别加11%蔗糖—卵黄稀释液(3号液);11%蔗糖—0.1%柠檬酸三钠—卵黄稀释液(5号液);5%葡萄糖—卵黄稀释液(8号液)。精子活力达8~9级。用3%柠檬酸三钠—卵黄稀释液(2号液)稀释,精子活力2级。冷冻时,用11%蔗糖溶液100 mL中加16 mL鲜卵黄,加5 mL甘油,配制的3号冷冻稀释液稀释,解冻后,精子活力达4级。优于试验中选拟的其它配方(加入5 mL甘油的5号冷冻液,解冻后精子活力为3级;加入5 mL甘油的8号冷冻液,解冻后未见活的精子)。如果冷冻稀释液中甘油改为6 mL,则解冻后精子全部死亡。     

Effects of five cryoprotective agents on quality of sheep epididymal spermatozoa during pre-freezing

The objective of this study was to test five cryoprotective agents during ram epidydimal spermatozoa incubation (at 4 °C), of up to 3 h, typical equilibration time before the freezing step begins, in order to establish a starting point for future freezing and thawing protocols. The parameters analyzed were: progressive motility (PM), vitality, and the plasma membrane functional integrity by the hypoosmotic swelling (HOS) test. Testes and epididymides were collected immediately after death. The tail of both epididymides were isolated and spermatozoa were recovered constituting one sample (n=20). A Tes–Tris–Yolk extender was employed. The extender contained five alternative CPAs: Dimethylacetamide (DMA), Dimethyl sulfoxide (DMSO), Ethylene glycol (EG), Glycerol (GLY) and Propylene glycol (PG) at three final concentrations: 2.5%, 5.0% and 10.0%. Control groups consisted of samples mixed only with the extender, without any CPA. All sample groups were exposed to the CPAs for 1 h or 3 h at 4 °C. EG exposure yielded better responses in both PM and HOS test parameters compared to extender only and also the other CPAs. There was no difference among all the treatments regarding vitality. EG (with best results at 2.5%) is thus proposed as a good CPA (followed by DMA as an explorable alternative) for the implementation of forthcoming ram epididymal spermatozoa freezing protocols.