解冻温度和时间对牛精子活力的影响试验

[目的]为了找到较为理想的解冻温度与时间,为基层黄牛改良工作提供技术参考。在不同温度区、不同时间解冻牛细管冷冻精液,对解冻后的精子活力进行检测。[方法]采用50~90℃每隔10℃设一个温区解冻牛细管冻精,检测解冻后精液的活力。[结果]在50~90℃5个温度梯度下快速解冻不同时间后的精子活力均在0.35以上,其中90℃解冻3~4s,80℃解冻4~5s,70℃解冻4~6s,60℃解冻8~9s后的精子活力均大于0.4,显著高于其他时间解冻后的精子活力。[结论]不同温度、时间解冻后精子活力各异,其最佳解冻温度和时间为90℃解冻3~4s,80℃解冻4~5s,70℃解冻4~6s,60℃解冻8~9s。     

抗精子抗体对鸡繁殖性能的影响

种鸡受精率和孵化率的高低直接影响种鸡场的经济效益。通常影响种鸡受精和孵化的因素有 :种鸡质量、精液品质、输精方法、种蛋保存条件和时间、孵化条件等。很少有人考虑免疫因素引起的受精率下降和孵化率降低。笔者对某种鸡场受精率下降的原因进行试验和分析 ,证实该场种鸡受精率下降主要由母鸡体内的抗精子抗体所致。抗精子抗体的产生直接导致受精率下降 ,甚至不受精 ,并且影响血蛋率和孵化率 ,给种鸡场造成很大的经济损失。1　材料与方法1 .1　试验动物分组　从某鸡场受精率下降鸡群和受精率正常鸡群中选出部分鸡作为试验鸡 ,并分组单笼…     

冷冻保存对绵羊精子顶体蛋白酶活性的影响

为了检测冷冻保存对绵羊精子顶体蛋白酶活性的影响,试验采用改良的明胶膜片法对冷冻保存前后小尾寒羊精子顶体蛋白酶的活性进行研究。结果表明:冷冻保存后精子顶体蛋白酶阳性反应率[(47.00±2.55)%]和平均成环直径[(23.89±0.22)μm]与冷冻前精子顶体蛋白酶阳性反应率[(77.00±2.00)%]和平均成环直径[(37.26±0.47)μm]相比差异极显著(P<0.01)。说明冷冻保存对绵羊精子顶体蛋白酶活性造成显著性损伤。     

稀释后不同时间抗体对牛精子活率的影响

本实验测定稀释后不同时间鸡抗奶牛Y精子蛋黄抗体对牛精子活性的影响。试验证明:所提取的抗奶牛Y精子IgY样品对牛精子活率有一定的影响,抗体样品与精子抗原混合后会立即产生免疫效应,而是需要一定的时间,才能达到想要的免疫效果,所以在应用抗体和精子作用时,掌握二者作用的时间是很重要的。     

低温保存对绵羊精子质膜完整性的影响

为了探讨低温保存对绵羊精子质膜完整性的影响,研究采用低渗肿胀-伊红拒染(HOS-EY)法检测低温保存前后绵羊精子头膜和尾膜的完整性。试验设计了5个HOS-EY低渗染液浓度梯度组合(110,130,150,170,190 mOsm),按精子尾部肿胀与否和头部着色与否分为4种类型进行统计。结果表明:低温保存后,绵羊精子头膜、尾膜均完整的Ⅳ型精子发生率和头膜、尾膜均损伤的Ⅰ型精子发生率与鲜精相比分别极显著减少和增多(P<0.01),说明低温保存过程对精子质膜完整性有极显著影响;在低温保存过程中头膜损伤-尾膜完整的Ⅱ型精子发生率极显著增多(P<0.01),而头膜完整-尾膜损伤的Ⅲ型精子发生率显著减少(P<0.05),说明精子头膜或尾膜的损伤是独立发生的,且头膜比尾膜更易损伤。5种低渗液中,150 mOsm染液检测效果最好。     

蛋种鸡血清抗精子抗体与受精率关系的试验

在本世纪初 ,Ｍｅｉｃｈｎｉｋｏｆｆ( 1 90 0 ) ,Ｐｆｆｅｉｆｅｒ( 1 90 5)和Ｈｅｎｌｅ( 1 92 8)分别发现动物精子具有抗原性。据报道 ,在不育妇女血清和宫颈粘液中存在着抗精子体。但是 ,抗精子抗体引起种鸡不受精或受精率极低的现象未见报道。我们从受精率急剧下降的蛋种鸡群中选出 32只血清抗精子抗体阳性母鸡 ,检查这些鸡的受精情况 ,同时设立血清抗精子抗体阴性鸡作对照组进行比较 ,发现免疫学因素可以引起蛋种鸡不受精或受精率极低。1　材料和方法1 .1　试验动物　试验组是从受精率突然下降鸡群中选出的 32只血清抗精子抗体强阳性…     

屡配不孕奶牛血清抗精子抗体水平和孕酮含量的测定

应用精子凝集试验测定五个牧场共33头屡配不孕奶牛和86头正常牛的血清抗精子抗体水平,发现30头屡配不孕牛的血清稀释到1∶8时,仍可见明显的凝集反应,而85头正常牛的血清稀释到1∶8时,凝集反应阴性。因此,将1∶8的血清稀释倍数作为诊断母牛是否不孕的指标,阳性和阴性准确率分别可达90.91％和98.84％。此外,用微滴板酶免疫法测定8头屡配不孕牛和30头正常牛的血清孕酮含量分别为9.83±1.85和1.95±0.74n g/ml,两者统计差异显著(P<0.01)。     

Effect of Exogenous Progesterone on Post-thaw Capacitation and Acrosome Reaction of Bovine Spermatozoa

The aim of this work was to study the effect of progesterone (P4) on capacitation and acrosome reaction (AR) of post-thaw bovine spermatozoa in vitro. Spermatozoa were incubated (0-180 min) in capacitation medium supplemented with 0, 0.1, 1.0 and 10.0 microg/ml of P4. At different time intervals aliquots were taken to determine sperm plasma membrane lipid destabilization, or capacitation (AR induced by lysophosphatidylcholine) in spermatozoa. The second experiment aimed to study the effects of P4, as potential inducer of AR in heparin-capacitated spermatozoa. The acrosomal status and viability of spermatozoa were evaluated under an epifluorescence microscope using Ethidium homodimer/peanut agglutinin fluorescein isothiocyanate staining method. Plasma membrane scrambling in spermatozoa was assessed by a flow cytometer, using merocyanine staining. The results show that P4 at the concentrations used had no negative effects on sperm viability. Progesterone significantly enhanced sperm capacitation (p < 0.001), but had no effect on plasma membrane lipid stability (p > 0.05) and did not significantly increase the AR of heparin-capacitated spermatozoa (p > 0.05). Progesterone displayed its effects in a dose-dependent manner with a maximum effect of 10 microg/ml P4 at 180 min of incubation. The results demonstrate that in cryopreserved bovine semen, P4 acts as capacitating, but not as an AR-inducing agent.     

Effect of Bovine Sperm‐Bound Antisperm Antibodies on Oviductal Binding Index

This study was designed to test the hypothesis that sperm‐bound IgG and IgA decrease binding of bull spermatozoa to oviductal epithelial cells in vitro. Three ejaculates were cryopreserved from each of four antisperm antibody (ASA)‐negative satisfactory breeder bulls. Bulls were then immunized with autologous spermatozoa, and three ASA‐positive ejaculates were cryopreserved from each bull post‐immunization. First, microscopy methods were compared to select the most appropriate assay for evaluation of oviductal binding index (BI). The BI did not differ when the evaluation was performed under fluorescence microscopy (131.1 sperm/mm²; 62.5–251.1 sperm/mm²), phase‐contrast microscopy (160.5 sperm/mm²; 56.8–397.4 mm²) or their combination (116.4 sperm/mm²; 56.8–249.6 sperm/mm²) (Median; IQR). The combination of microscopy methods was selected as it allowed better visualization of cells. Then, BI was compared between ASA‐negative and ASA‐positive ejaculates, and the association between BI and ASA binding was evaluated. The BI was less in ASA‐positive (114.9; 0 to 201.8 sperm/0.1 mm²) than ASA‐negative samples (218.9; 24.7 to 276.8 sperm/0.1 mm²) (P = 0.0002). This reduction in BI was significant in three of the four bulls. Regression analysis identified a negative association between BI and the percentage of IgG‐bound (p = 0.013) but not IgA‐bound spermatozoa. In conclusion, sperm‐bound IgG decreased the ability of bovine spermatozoa to bind to oviductal epithelial cells in vitro.     

Effect of Progesterone and Oestradiol on Sperm–zona Binding and Acrosome Reaction in Bovine Spermatozoa after Thawing

This study was conducted assess spermatozoa binding capacity to the oocyte in the presence of 0.1 or 0.5 microg/ml progesterone (P4) or a combination of 0.5 microg/ml P4 with 0.1 microg/ml oestradiol (OE). The number of oocyte-bound spermatozoa in the presence of progesterone was significantly higher (p < 0.05 to p < 0.001) when compared with the control samples, that were incubated in the absence of P4. Spermatozoa binding to the zona pellucida (ZP) of the oocyte were concentration-dependent - significantly higher numbers of spermatozoa were bound in the presence of 0.5 microg/ml P4, when compared with that of 0.1 microg/ml P4. Oestradiol at 0.1 microg/ml concentration used impaired the effect of progesterone-mediated sperm-oocyte binding. The incidences of acrosome-reacted (AR) spermatozoa bound to the ZP - following 0, 60, 120 and 180 min. incubation in the presence and absence of 1 microg/ml progesterone was also assessed. Only at 180 min of incubation a higher (p < 0.001) incidence of the AR-spermatozoa was found in sperm-ZP complexes incubated in the presence or absence of progesterone, being 56.5 +/- 11.1 and 43.2 +/- 8.8 % respectively. In conclusion, progesterone enhances the sperm-ZP binding capacity. Progesterone affects the incidences of AR on zona-bound spermatozoa only after prolonged co-culture.     

Effects of Dilution Rate on the Motility and Acrosome Morphology of Boar Spermatozoa Stored at 15 °C

The objective of this investigation was to establish the optimal extent of dilution for storage of boar spermatozoa at 15°C in Kiev diluent. The dilution titers used for the sperm-rich fraction of ejaculates from 8 boars ranged from 1:2 to 1:50. Seminal doses were stored for 10 days. Motility and acrosome morphology were evaluated after 1, 3, 5, 7, and 10 days of storage. The percentages of motile spermatozoa after 24 and 72 hours of storage were significantly higher for dilution rates between 1:7 and 1:11 than for dilution rates lower than 1:7 or higher than 1:11 (p < 0.05). The percentages of spermatozoa with normal acrosomes after 24, 72, and 120 hours of storage were significantly higher for dilution rates between 1:8 and 1:11 than for dilution rates lower than 1:8 or higher than 1:11 (p < 0.01 ).     

Effects of Increasing Concentrations of Minocin on the Motility of Bovine Spermatozoa Processed in Various Extenders

The effect of minocycline hydrochloride (Minocin) on bovine spermatozoa was studied in eggyolk-citrate, Tris buffer and whole milk extenders. Each of the extenders contained penicillin, streptomycin, lincomycin-spectinomycin and four levels of minocin (10, 260, 510 and 760 μg/ml). Split ejaculates from Holstein sires were diluted in each of the extenders. This was followed by microscopic evaluation for progressive motility after initial dilution at 32°C, after cooling at 5°C and complete dilution, immediately after freezing and after 14 days of storage in liquid nitrogen. Under the experimental conditions employed, a decrease in the percent progressive motility was observed in the eggyolk-citrate and Tris buffer extenders with increasing concentration of minocin. Little or no difference in the percent progressive motility in the whole milk extender, either before or after freezing was observed when the minocin concentration was elevated.     

哺乳类动物精子的获能和顶体反应

介绍了在生殖过程中的2个重要的生理变化--获能和顶体反应,并综述了最近几年来在生殖生物学领域关于获能与顶体反应机制方面的最新成果.结果显示,cAMP、Ca2+、咖啡因等因素对精子获能有促进作用,ZP3、Ca2+、cAMP、肝素等因素对顶体反应有促进作用.所有研究成果表明,精子的荻能和顶体反应与精子膜的生理变化有着密切关系.     

The Effect of Season on Spermatozoa Motility,Plasma Membrane and Acrosome Integrity in Fresh and Frozen–Thawed Semen from Xinong Saanen Bucks

The aim of this study was to evaluate whether the season of ejaculate collection influences seminal quality parameters of pre‐ and post‐freeze–thawing in Xinong Saanen bucks. Ejaculates were collected from eight bucks throughout the four seasons (spring, summer, autumn and winter) in a 12 months’ time period, identified in the Northern Hemisphere. Semen samples were evaluated by the combinations of conventional and Computer‐Assisted Sperm Analysis (CASA) when fresh and after frozen–thawed, respectively. The results clearly demonstrated that season of ejaculate collection influenced (p < 0.05) fresh semen quality. Highest semen quality was observed during autumn. On the contrary, undesirable indices (significantly lower, p < 0.05) were observed in winter as compared with the other remaining seasons. CASA has clearly shown the influences of seasonal variations on semen motility parameters. Furthermore, season of ejaculate collection was also found to influence sperm freezability. Semen characteristics after frozen–thawed followed a similar pattern with that of fresh ejaculate except in spring. The results revealed that sperm quality was higher (p < 0.01) in summer and autumn than in spring and winter. In conclusion, seasonal variation influences semen quality in Xinong Saanen bucks. In addition to summer and autumn, fresh ejaculates in spring can also be successfully used for AI. Sperm from ejaculates collected during summer and autumn are more suitable for cryopreservation. Hence, it is possible to increase the efficiency of goat breeding by manipulating the seasonal variations of semen quality for immediate AI and/or cryopreservation.     

Studies on Motility and Fertility of Cooled Stallion Spermatozoa

This study on extended, cooled stallion spermatozoa aimed to compare the ability of three extenders to maintain sperm motility during 24 h of preservation, and to describe pregnancy and foaling rates after artificial insemination (AI) of stallion spermatozoa stored and transported in the extender chosen from the in vitro study. After 6 and 24 h of preservation, motility, both subjective and evaluated by the motility analyzer (total, progressive and rapid), was lower in non-fat, dried skim milk-glucose than in both other extenders: dried skim milk-glucose added to 2% centrifuged egg yolk, and ultra high temperature treated skim milk-sugar-saline solution added to 2% centrifuged egg yolk (INRA82-Y). Rapid spermatozoa and sperm velocity parameters, after 24 h, were significantly higher in INRA82-Y. In the fertility trial, semen collected from three Maremmano stallions, diluted in INRA82-Y, and transported in a refrigerated Styrofoam box, was used to inseminate 56 mares of the same breed. Pregnancy rates after the first cycle and per breeding season were significantly higher for the 31 mares inseminated in three AI centres (54.8 and 80.6%, respectively) than for the 25 mares inseminated at the breeder's facilities (28.0 and 52.0%). Foaling rates were not significantly different between the AI centres mares (54.8%) and the other mares (44.0%). In conclusion, INRA82-Y yielded satisfactory pregnancy and foaling rates, especially when employed in the more controlled situation of an AI centre, and can therefore be included among those available for cooled stallion semen preservation.     

Influence of Thawing Diluents on Vitality,Acrosome Morphology,Ultrastructure and Enzyme Release of Deep Frozen Roar Spermatozoa*

The present investigation was performed to study the effect of freezing and thawing on boar spermatozoa. Thirty-one ejaculates from four boars were investigated after thawing in three different thawing diluents (seminal plasma, OLEP, isotonic glucose solution).From each ejaculate one sample of 1 × 10⁹ spermatozoa was thawed in each of the thawing diluents. Each sample was examined in a thermoresistance test in which motility was stimulated with caffeine 30 min. and 3 hrs. after thawing. Furthermore, acrosome morphology and ASAT release from the spermatozoa were investigated for each sample. One ejaculate from the two most frequently used boars was examined by electron microscopy after thawing in each of the thawing diluents.Differences in the aspects studied appeared between isotonic glucose solution and the other two thawing diluents in the thermoresistance test, in the response to caffeine stimulation 3 hrs. after thawing and in the amount of ASAT released from the spermatozoa. The influence on the acrosome morphology varied between the thawing diluents, but the acrosomal alterations did not seem to be connected with the damage reflected by the thermoresistance test and by the measurement of extracellular ASAT activity.The ultrastructural investigation showed that all spermatozoa examined had some degree of ultrastructural alteration as compared with freshly ejaculated boar spermatozoa treated in the same way. This alteration could not be related to any of the thawing diluents.Of the various laboratory tests the thermoresistance test and the measurement of ASAT release are suggested to be sensitive indicators of sperm damage during freezing and thawing. These tests might be useful indicators of variations in sensitivity of spermatozoa to the freezing-thawing procedure.