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.     

五种糖类对犬精液冷冻保存效果的研究

选取8只身体健康、性欲旺盛的比格公犬,采集其精液,对鲜精进行质量检测,主要包括颜色、射精量、精子活率、活力和pH。选取精子活率达到70%以上犬精液用于后续精液冷冻试验。分别将含有葡萄糖、果糖、蔗糖、乳糖和海藻糖的精液稀释液与精液按照1∶2的比例进行稀释。经冷冻解冻后,进行活率、活力、质膜完整性和顶体完整性的精子质量检测。通过对新鲜精液进行品质检测,结果显示5只合格用犬的平均射精量为2.85 mL,密度为2.01×10~8个/mL,pH为6.56。含有果糖的冷冻稀释液中精子活率和活力最高,分别达59.90%和54.00%;其次是添加葡萄糖和乳糖的稀释液中活率较高,分别为59.21%和56.73%,且两组稀释液中精子解冻后活力均为52.00%。进一步评估精子解冻后质膜完整率,结果显示葡萄糖和果糖组显著高于其他组,分别达48.73%和49.52%;而蔗糖添加组精子质膜完整率最低,为42.21%。稀释液中添加果糖的精子解冻后顶体完整率显著高于其他组,而添加蔗糖组顶体完整率最低。在比格犬的精液冷冻保存中,添加果糖的冷冻稀释液能显著提高精子的活率和活力,从而达到提高冻精质量的效果。     

新西兰兔精液冷冻保护剂的筛选

本试验的目的是分析在新西兰兔精液冷冻保存稀释液中分别添加不同浓度的海藻糖、透明质酸、维生素E(Ve)、超氧化物歧化酶(SOD)对兔精液冷冻保存效果的影响,以冻后精子活率、质膜完整性、顶体完整率等作为质量评定指标,筛选出效果较好的新西兰兔精液的冷冻保护剂种类及浓度。结果表明,精液冷冻保存稀释液中添加3种浓度的海藻糖均未提高兔精液冷冻后的精子活率、质膜完整率和顶体完整率(P0.05);添加0.5%和1%的透明质酸提高了兔精液冷冻后的精子活率(P0.05),但各组间质膜完整率和顶体完整率无显著差异;添加2 g/L Ve提高了兔精子4℃平衡后的活率、冷冻后精子活率、质膜完整率和顶体完整率(P0.05);添加4 000 IU的SOD提高了兔精子4℃平衡后的活率、冷冻后精子活率、质膜完整率和顶体完整率(P0.05)。结果证实,在新西兰兔精液冷冻保存稀释液中添加适宜浓度的Ve和SOD可提高兔精液冷冻后的精子活率、质膜完整率和顶体完整率。     

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。     

海藻糖对民猪精液冷冻保存的影响

为研究海藻糖在民猪精液冷冻中的作用,获得最佳民猪精液冷冻液成分,本试验在BTS、Modena和Zorlesco 3种稀释液基础上添加0.15 mol/L海藻糖,及在Zorlesco稀释液中分别添加0 mol/L、0.1 mol/L、0.15 mol/L和0.2 mol/L的海藻糖,研究海藻糖在不同稀释液中及其不同浓度对冷冻的民猪精子活率、质膜完整率、顶体完整率和线粒体膜电位的影响。结果表明,在Zorlesco稀释液中添加0.15 mol/L海藻糖可明显提高民猪冷冻精子的质量,使精子活率、质膜完整性、顶体完整率和线粒体活性分别达到(44.0±2.4)%、(58.2±2.4)%、(53.2±2.1)%和(51.3±2.3)%,为各组最佳(P<0.05)。将0.15 mol/L海藻糖分别添加在BTS、Modena和Zorlesco3种稀释液中发现,其中在Zorlesco稀释液添加海藻糖效果优于其他两组(P<0.05)。但海藻糖对冷冻前精子的保护作用不明显(P>0.05)。因此,在Zorlesco稀释液中添加1.5 mol/L的海藻糖能够明显提高民猪精子冷冻后质量,是民猪冷冻保存的适宜保护液。     

海藻糖和甘油相互协同提高绒山羊精液冷冻保存品质

本实验旨在研究不同浓度的海藻糖和甘油相互协同对绒山羊精液冷冻保存的影响。将0 mmol/L (T0)、50mmol/L(T50)的海藻糖和0%(G0)、1%(G1)、2%(G2)、3%(G3)的甘油分别组合为T0G0、T0G1、T0G2、T0G3、T50G0、T50G1、T50G2和T50G3。以Tris-柠檬酸-葡萄糖(TCG)为基础稀释液,分析不同组合对绒山羊精液冷冻保存的影响。检测解冻后精子活力、运动参数、DNA完整率、顶体、质膜完整率、抗氧化水平。结果表明:海藻糖和甘油联合添加时精子冷冻保存效果显著高于单独添加海藻糖或甘油组,其中T50G1组作用最显著。在基础稀释液中添加50 mmol/L(T50)的海藻糖时,精子冷冻解冻后的活力、质膜完整率随着甘油浓度的升高而降低,而在基础稀释液中不添加海藻糖时,精子冷冻解冻后的活力、质膜完整率随着甘油浓度的升高而升高。综上表明,海藻糖和甘油通过协同作用提高精子冷冻保存效果,两者发挥作用的最适浓度为50 mmol/L海藻糖和1%甘油,并且海藻糖和甘油协同作用对精子活力以及质膜完整性具有浓度依赖性。     

芝麻酚对猪精液冷冻保存效果的影响

为了探究芝麻酚对猪精液冷冻保存效果的影响,用手握法采集成年杜洛克公猪精液,预处理后添加不同浓度芝麻酚(0,0.05,0.10,0.15,0.20和0.25g/L)的冷冻稀释液进行稀释,冷冻-解冻后检测猪精子活率、质膜完整性(低渗肿胀试验)、线粒体活性、顶体完整性、DNA完整性以及超氧化歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性等。结果显示:当芝麻酚添加浓度为0.20g/L时,解冻后精子活率、线粒体活性、质膜完整率和顶体完整率为最高,相比较于对照组,分别提高了12.67%、19.07%、18.78%和14.09%(P0.05);MDA含量最低为2.04nmol/mL(P0.05);SOD和GSH-Px酶活最高为73.04U/mL和237.59U/I(P0.05)。当芝麻酚添加浓度为0.25g/L时,DNA完整性最高为72.46%(P0.05)。当芝麻酚添加浓度为0.15g/L时,CAT酶活最高为3.44U/mL(P0.05)。结果表明:与对照组相比较,在猪精液冷冻稀释液中添加适当浓度的芝麻酚能显著提高解冻后猪精子活率、功能完整性和抗氧化能力(P0.05),且当芝麻酚的浓度为0.2g/L时对猪精子冷冻保存效果最好。研究结果表明,芝麻酚作为一种天然抗氧化剂,对猪精子冷冻保存具有良好的效果。     

五种糖对马精子低温保存及冷冻效果的影响

为了研究单独或组合添加葡萄糖、果糖、乳糖、棉籽糖及海藻糖对马精子低温和冷冻保存效果的影响,试验选取4匹6~12岁公马进行精液收集,经离心浓缩处理后置于含有不同糖的低温或冷冻稀释液中保存,低温保存1,24,48,72,96小时时检测活精子比例(total motility,TM)和直线运动精子比例(progressive motility,PM),评价糖对精子低温保存效果的影响,冷冻后精液于37℃水浴解冻后检测TM、PM、质膜完整率及高线粒体膜电势评价不同糖对精子冷冻效果的影响。结果表明:单独添加乳糖和棉籽糖组低温保存24 h后精液TM和PM明显低于葡萄糖、果糖及海藻糖组,葡萄糖、乳糖分别与其他几种糖两两组合低温保存1,24,48,72,96小时时精液TM和PM差异不显著,单独添加棉籽糖组精子冻融后TM和PM显著低于果糖和海藻糖组(P0.05),但精子质膜完整率和高线粒体膜电势显著高于其他各组(P0.05),单独添加葡萄糖、果糖、海藻糖及乳糖组精子冻融后TM、PM及高线粒体膜电势均无显著差异(P0.05),添加果糖组冻融后精子质膜完整性显著低于葡萄糖组(P0.05)。不同糖组合精子冻融后,乳糖+葡萄糖+海藻糖组精子质膜完整率显著高于乳糖+果糖组、乳糖+海藻糖组、乳糖+葡萄糖+果糖组、乳糖+果糖+海藻糖组(P0.05),乳糖+葡萄糖+果糖组精子高线粒体膜电势显著高于乳糖+果糖组(P0.05),与其他组相比差异不显著(P0.05)。仅含棉籽糖、乳糖或棉籽糖+乳糖的稀释液不适合于马精液低温保存,不同糖组合并没有获得比经典葡萄糖+乳糖更好的低温和冷冻保存效果。     

红景天多糖对藏猪精液冻后品质及精子基因组DNA甲基化的影响

在藏猪精液的冷冻液中添加不同质量浓度的红景天多糖(0,2,4,6,8,10mg/L),制成高密度细管冻精,以冷冻解冻后精子活率、精子畸形率、精子顶体完整率和质膜完整率为精液品质的评价指标,筛选最适红景天多糖添加质量浓度;用甲基化荧光定量法检测3组(鲜精组、未添加组、最适添加组)精子基因组DNA甲基化的水平。结果显示:添加红景天多糖质量浓度为6mg/L组的精子活率显著高于其他组(P<0.05),该组精子畸形率、精子顶体完整率、精子质膜完整率也显著好于未添加组(P<0.05);这3组精子基因组的DNA甲基化水平(0.610 5±0.080 0,0.945 7±0.043 7,0.680 2±0.051 0)中,最适添加组虽显著高于鲜精组(P<0.05),但却显著低于未添加组(P<0.05)。结果表明:在藏猪精液冷冻液中添加质量浓度6mg/L的红景天多糖不仅可以明显改善藏猪精液冻后品质,而且可以明显减少冷冻对藏猪精子基因组DNA甲基化水平的影响,这将为提高藏猪精液冷冻保存效果的进一步研究提供参考。     

褪黑素对绒山羊精液冷冻保存效果的影响

为了研究褪黑素对绒山羊精液冷冻保存效果的影响,在冷冻稀释液中外源补充不同浓度(0.125,0.250,0.500,1.000 mg/mL)的褪黑素进行冷冻试验,冷冻解冻采用计算机辅助精液分析系统(CASAS)和流式细胞仪分别检测精子活率、质膜完整率、顶体完整率以及精子细胞中活性氧(ROS)的含量。结果表明:在冷冻稀释液中添加褪黑素能够显著降低精子细胞中ROS的含量,而且在冷冻稀释液中添加浓度为0.500 mg/mL的试验组绒山羊精子活率(53.3%)、质膜完整率(44.6%)、顶体完整率(77.9%)均显著高于空白对照组(47.8%、36.3%和53.2%)(P0.05)。说明在绒山羊精液冷冻稀释液中添加0.500 mg/mL褪黑素能够显著提高绒山羊精子抗氧化能力和冷冻保存效果。     

二甲基甲酰胺对猪精液冷冻保存效果的影响

用二甲基甲酰胺(DMF)完全替代甘油,比较不同平衡时间和不同DMF添加量对猪精液冷冻保护效果的影响。结果表明,DMF能完全替代甘油,获得较好的冷冻保护效果。最佳平衡时间为90 min,解冻后精子活力为(44.57±0.72)%,显著高于对照组和其他组(P0.05)。当DMF添加量为5%时,冻后精子活力、活率、线粒体活性、顶体完整率和质膜完整率分别为(49.91±0.39)%(、46.51±0.26)%、(47.51±0.52)%(、49.84±0.56)%、(46.30±1.61)%,均显著高于2%、3%、6%DMF添加组(P0.05),但与4%DMF添加组相比,冻后精子活力、活率和质膜完整率差异不显著(P0.05)。本试验结果表明,DMF最适添加量为5%。     

Cryopreservation of boar semen by egg yolk-based extenders containing lactose or fructose is better than sorbitol

The present study determined the effect of different types of sugars (lactose, fructose, glucose and sorbitol) used in egg yolk-based extender on the post-thawed boar semen quality. Twenty-two ejaculates from 6 fertility-proven Yorkshire boars were cryopreserved by liquid nitrogen vapor method. Sperm motility, viability, acrosome integrity and intact functional plasma membrane were determined at 0, 2 and 4 hr after thawing. It was found that the lactose-based extender resulted in a higher percentage of post-thawed sperm motility, viability, intact acrosome and functional plasma membrane than sorbitol-based extender (P<0.05) and fructose-based extender yielded a higher post-thawed sperm motility and viability than sorbitol-based extender (P<0.05). It could be concluded that sorbitol was not an effective sugar for the cryopreservation in boar semen.     

海藻糖对猪精液冷冻保存效果的影响

在传统的Tris-柠檬酸-葡萄糖稀释液基础上，分别添加25％、50％、75％、100％的海藻糖，研究不同浓度海藻糖对猪精液冷冻后精子质量的影响。结果表明，海藻糖相对于对照TCG稀释液能够显著改善和提高猪精液的冷冻效果，其最佳添加浓度为25％，冷冻-解冻后猪精子活力、活率、线粒体活性、质膜完整性以及顶体完整率均显著提高（P〈0．05），分别达到41．38％、46．34％、44．56％、43．51％和64．09％。海藻糖可以明显抑制精子获能，获能处理前精子获能率仅为3．68％，而获能处理后达到41．82％，有利于促进精子获能。精液稀释液中甘油的适宜添加浓度为2％，海藻糖只有与甘油共同作用，才能在冷冻-解冻过程更加有效地保护精子。猪精子活力、活率、线粒体活性、质膜完整率、顶体完整率等之间存在极显著的正相关关系（P〈0．01），而与获能处理前精子的获能率存在显著的负相关关系（P〈0．05）。     

Breed of Boar Influences the Optimal Concentration of Gamma‐oryzanol Needed for Semen Cryopreservation

The aim of this study was to investigate the influence of boar breed on the optimal concentration of gamma‐oryzanol on the qualities of cryopreserved boar semen. Semen was collected from 20 boars (10 Duroc, 5 Large white and 5 Landrace boars). The semen sample was divided into five groups (A–E) according to the concentration of gamma‐oryzanol in extender II, that is 0, 0.08, 0.16, 0.24 and 0.32 mm , respectively. The semen was cryopreserved by nitrogen vapour and storage in nitrogen tank (?196°C). After storage for a week, samples were thawed at 50°C for 12 s and evaluated for progressive motility, sperm viability and acrosome integrity. The results demonstrated that gamma‐oryzanol significantly improved progressive motility, viability and acrosome integrity of frozen–thawed boar semen. Considering the influence of breeds on the optimal concentration of gamma‐oryzanol, for Duroc boar, gamma‐oryzanol at 0.16 mm (group C) yielded the highest percentage of progressive motility, sperm viability and acrosome integrity. For Large white and Landrace boars, gamma‐oryzanol at 0.24 mm (group D) showed a significantly higher percentage of progressive motility, viability (not significant in Landrace) and acrosome integrity than other concentrations. In conclusion, the optimal concentration of gamma‐oryzanol needed for boar semen cryopreservation in lactose–egg yolk (LEY) freezing extender is not only depended on individual boar but also breed of boar, that is 0.16 mm for Duroc and 0.24 mm  for Large white and Landrace.     

The Cryoprotective Effect of Trehalose Supplementation on Boar Spermatozoa Quality

In order to improve boar sperm quality during frozen-thawed process, the influence of the presence of trehalose on success of cryopreservation of boar sperm were investigated. We evaluated freeze-thawing tolerance of boar spermatozoa in a base cooling extender with the addition of different trehalose concentrations (0, 25, 50, 100 and 200 m m ), and try to determine the optimum concentration of trehalose. We chose sperm motility, mitochondrial activity, acrosome integrity and membrane integrity as parameters to evaluate cryopreservation capacity of boar spermatozoa. We obtained the best results for 100 m m trehalose-supplemented extenders, with values of 49.89% for motility, 44.69% for mitochondrial activity, 66.52% for acrosome integrity and 44.61% for membrane integrity, while freeze-thawing tolerance diminished significantly for 200 . The synergic effect of trehalose and glycerol resulted in better cryosurvival of boar spermatozoa than that of a single cryoprotectant. In conclusion, when trehalose-supplementation was added up to 100 m m , trehalose confers a greater cryoprotective capacity to the extender, and the sperm motility, mitochondrial activity, membrane integrity and acrosome integrity parameters were significantly improved during frozen-thawed process.     

Effect of Docosahexaenoic Acid on Quality of Cryopreserved Boar Semen in Different Breeds

During the cryopreservation process, the level of polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), in the sperm plasma membrane decreases significantly because of lipid peroxidation, which may contribute to sperm loss quality (i.e. fertility) of frozen–thawed semen. The aim of this study was to investigate the effect of supplementation of DHA (fish oil) in freezing extender II on frozen–thawed semen quality. Semen from 20 boars of proven motility and morphology, were used in this study. Boar semen was split into four groups, in which the lactose–egg yolk (LEY) extender used to resuspend the centrifuged sperm pellet was supplemented with various levels of fish oil to reach DHA level of 1X (group I, control, no added fish oil), 6X (group II), 12X (group III) and 18X (group IV). Semen solutions were frozen by using a controlled rate freezer. After cryopreservation, frozen semen was thawed and evaluated for progressive motility, viability by using SYBR‐14/Ethidiumhomodimer‐1 (EthD‐1) staining and acrosome integrity by using FITC‐PNA/EthD‐1 staining. There was a significantly higher (p < 0.001) percentage of progressive motility, viability and acrosome integrity in DHA (fish oil) supplemented groups than control group. Generally, there seemed to be a dose‐dependent effect of DHA, with the highest percentage of progressive motility, viability and acrosome integrity in group‐III. In conclusion, supplementation of the LEY extender with DHA by adding fish oil was effective for freezing boar semen as it resulted in higher post‐thaw plasma membrane integrity and progressive motility.     

Metformin blocks mitochondrial membrane potential and inhibits sperm motility in fresh and refrigerated boar spermatozoa

Metformin is clinically used to treat diabetes. Given its role‐impacting metabolism, metformin has been also added to semen cryopreservation media showing specie‐dependent effects. We aimed to investigate metformin effects in both fresh (38.5°C for 2, 24 hr) and refrigerated (17°C for 10 days) boar spermatozoa. Metformin (2 hr) does not affect fresh sperm viability, membrane lipid organization nor acrosome integrity. However, metformin (24 hr) blocks sperm ΔΨm and significantly reduces % motile spermatozoa (65%), % progressive spermatozoa (50%), % rapid (100%), velocities VCL (69%), VSL (86%), VAP (78%) and motility coefficients. Metformin‐including extender does not modify sperm viability, membrane lipid organization or acrosome integrity. Furthermore, it significantly reduces high ΔΨ‐population spermatozoa at refrigeration day 4. Metformin also significantly reduces sperm motility during refrigeration. Summarizing, metformin inhibits both boar sperm ΔΨ and motility in any sperm condition studied: fresh and refrigerated. These findings dissuade metformin as an additive to improve boar sperm quality.     

近交五指山小型猪精液冷冻保存技术的研究

用液氮熏蒸法在氟板上制作冻精颗粒,以解冻后的精子活率、活力和质膜完整性为判定指标,比较4种冷冻稀释液及不同冷冻-解冻程序对五指山小型猪精液冷冻的效果。结果表明:①Ⅳ号冷冻稀释液冷冻解冻后精子的活率(0.610±0.036)、活力(0.427±0.025)和质膜完整性(0.503±0.015)均显著高于Ⅰ、Ⅱ和Ⅲ号冷冻稀释液(P<0.05)。②实验中精液在4℃冰箱中平衡降温2 h的精液精子活力、质膜完整性均好于在17℃平衡3 h再放入4℃冰箱中平衡2 h的解冻效果,而且精子活率差异显著(P<0.05)。③湿解法的效果优于干解法。     

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.     

The Effect of Trehalose Supplementation of INRA-82 Extender on Quality and Fertility of Cooled and Frozen-Thawed Stallion Spermatozoa

Stallion semen cryopreservation is often associated with poor post-thaw sperm quality. Sugars act as nonpermeating cryoprotectants. The aim of the present study was to evaluate the cryoprotective effect of trehalose on stallion sperm quality and field fertility rates subjected to cooling and freeze–thaw process. Semen samples were collected from six Arabian stallions, divided into five different treatments in a final concentration of 100 × 10⁶ sperm/mL by using INRA-82 extender containing 0, 25, 50, 100, and 200 mM of trehalose then subjected to both cold storage and cryopreservation. Sperm motility, acrosome, plasmatic membrane, and DNA integrity were analyzed, and 57 mares were used to evaluate the field fertility of chilled and frozen-thawed semen. Results showed that the extender containing 100 mM trehalose only increased the functional acrosomal, plasma membrane, and DNA integrities. The inclusion of 50 mM trehalose in semen extender resulted in significantly (P < .05) increased post-thaw total motility compared to the control group, and chilled semen achieved higher pregnancy rates compared to the frozen-thawed one. Pregnancy rate of mares inseminated with frozen-thawed semen (P < .05; 46.15% vs. 36.36%, respectively) was lower than those inseminated with chilled semen (76.47% vs. 68.75%, respectively) but higher than control. In conclusion, addition of 50 mM trehalose yielded the highest quality stallion semen after cooling and post-thawing in terms of motility, integrities of acrosome, membrane, and DNA as well as improved field fertility.