抗氧化剂在猪精液冷冻保存技术中的应用

利用冷冻精液进行人工授精的研究由来已久,但与鲜精和液态保存的精液相比,猪冷冻精液的受胎率、分娩率和窝仔数均较低,难以实现利用冷冻精液实现大规模商业化育种的目标。目前国外猪冷冻精液商业化应用比例不到人工授精的1％,并且各国的具体情况也不尽相同,而国内尚未有商业化推广的成功范例。即使是利用现有最好的冷冻技术,解冻后的活率也低于50％。     

抗氧化剂在猪精液冷冻保存技术中的应用

近年来,在猪精液冷冻保存技术中应用抗氧化剂以提高冷冻精液质量的研究受到了广泛关注。国内外相继报道,添加甲基黄嘌呤、丁羟甲苯、谷胱甘肽、超氧化物歧化酶和过氧化物酶、维生素E及褪黑素等抗氧化剂可以有效改善冷冻保存猪精液的精子运动学参数,保护精子质膜、顶体和DNA完整性,提高冷冻-解冻后精子的受精能力。为了更好地了解抗氧化剂的抗精子冷冻损伤的作用机制、客观地评价不同抗氧化剂的应用效果及展望其在猪精液冷冻保存技术中的应用前景特综述如下。     

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。     

不同抗氧化剂对猪精液冷冻保存效果的影响

在LEY冷冻稀释液基础上分别添加不同浓度维生素C(0、5、10、20、40、60 mmol/mL)、维生素E(0、0.2、0.5、1.0、2.5、5.0 mg/mL)、SOD(0、100、200、400、600 IU/mL)、CAT(0、50、100、200、300 IU/mL)、GSH(0、1、5、10 mmol/mL)等抗氧化剂,检测冷冻-解冻后精子活力、活率、质膜完整率、顶体完整率、平衡后和解冻后精子MDA含量,以观察5种抗氧化剂对猪精液冷冻保存效果的影响。结果表明:在冷冻稀释液中联合添加100 IU/mLSOD和200 IU/mL CAT明显提高冷冻-解冻后精子活力、活率、质膜完整率和顶体完整率(P<0.01)。     

抗氧化剂对猪精液冷冻保存效果的影响

目前,猪的人工授精以鲜精和常温保存的液态精液为主,冷冻精液在人工授精中所占的比例不足1%,由于解冻后精子复苏率较低、异常精子多、受胎率低等原因,在生产上猪的精液冷冻与牛的精液冷冻相比尚未得到普遍推广、应用。精子的冷冻处理在畜牧业上是一个重要且具有特殊优势的操作过程。提高精子冷冻技术水平,需要对配子的生理学知识和精子收集、处理过程的生化改变有更深入的了解,这些     

抗氧化剂在公猪精液冷冻保存中的应用

近几年来,在公猪精液冷冻稀释液中添加抗氧化剂以提高冷冻精液质量的研究受到广泛的关注。添加谷胱甘肽、超氧化物歧化酶和过氧化物酶、维生素E、L-半胱氨酸和L-谷氨酰胺、中草药成分等抗氧化剂可以有效地防止氧化损伤,提高解冻后精子活率、精子成活力、质膜与顶体完整性等,进而提高冷冻保存精液的受精能力。作者综述了抗氧化剂的抗精子冷冻损伤的作用机制及不同抗氧化剂的应用效果,并对其在公猪精液冷冻保存中的应用前景进行了展望。     

精液冷冻保存中抗氧化剂的作用机制研究进展

在精液冷冻保存中,过量活性氧(Reactive Oxygen Species,ROS)会对精子细胞造成严重损伤,在冷冻过程中添加抗氧化剂可以有效地减少精液在冷冻保存过程中产生过量的ROS,提高精子细胞超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性,降低丙二醛(MDA)水平,从而保护精子细胞免受氧化应激损伤,提高精液质量。目前,在精液抗氧化剂研究中最常用的是白藜芦醇、虾青素和黄芪多糖等,但这些抗氧化剂在精液冷冻研究中仅做了功能验证,其抗氧化机制尚不清楚。本文主要探讨以白藜芦醇、虾青素和黄芪多糖为代表的抗氧化剂在畜禽精液冷冻过程中对精子功能的影响和抗氧化保护机制,为畜禽精液冷冻研究提供参考。     

猪精液大剂型冷冻保存的研究进展

本文概述了近年来对猪精液大剂型冷冻技术的研究工作,并从冷冻稀释液、稀释方法和冷冻解冻程序方面阐述了影响猪精液大剂型冷冻的因素,探讨了存在的问题并进行了展望。     

水苏糖对猪精液冷冻保存效果的影响

为了提高猪精液冷冻保存效果．试验采用在传统的ZO稀释液基础上分别添加1％、2％、4％、8％的水苏糖的方法．研究不同浓度水苏糖对猪精液冷冻后精子质量的影响。结果表明,水苏糖相对于ZO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4％,冷冻一解冻后猪精子活力、活率、质膜完整性以及顶体完整率均显著提高,水苏糖可以明显抑制精子获能,获能处理前精子获能率仅为32．4％,而获能处理后降为28．6％。有利于抑制精子获能,精液稀释液中甘油的适宜添加浓度为3％,说明水苏糖与甘油共同作用能在冷冻一解冻过程更加有效地保护精子。     

浅析抗氧化剂对猪精液保存的影响因素

近年来,随着畜牧业的发展,家畜精液保存技术在生产实践中发挥着重要作用。在精液保存过程中,体内外环境的差异打破了精子所处环境的动态平衡,保存期间产生大量的活性氧（reactive oxygen species,ROS）。过量的ROS会与精子质膜发生氧化反应,破坏精子的功能和结构完整性,使其活力和质量降低,影响受胎率。为了降低ROS对精液的损伤,加入外源抗氧化剂可以有效抑制和清除ROS,避免精子细胞受到破坏,进而提高精液品质。文章对抗氧化剂的作用机制、抗氧化剂的种类以及在猪精液保存上的应用等方面进行综述。     

马精液冷冻保存研究进展

从马精液冷冻程序过程中不同采精方法、稀释液添加剂、冷冻保存承载工具等方面,概述了影响精液冷冻的因素,并介绍了解冻后精液的人工授精方法。     

猪精子冷冻损伤与保护剂的研究进展

猪精液冷冻保存技术主要是利用液氮(-196℃)作为冷源,在超低温的环境下使精子生理代谢完全暂停,实现长期保存的目的.猪精子在低温环境主要损伤是细胞内结冰晶造成的机械损伤、游离的活性氧造成的化学损伤,对这两种损伤机制研究是国内外科研工作者们的研究热点.文章主要简述猪精液冷冻技术发展简况,精子在冷冻过程中受损伤机制和现阶段...     

抗氧化剂在哺乳动物精液冷冻保存中的应用

从20世纪50年代哺乳动物精液冷冻研究开始,国内外研究者通过几十年对精液冷冻程序以及冷冻稀释液、解冻液等的筛选,牛、羊等家畜的冷冻精液已经商业化生产,广泛用于人工授精进行优良品种的繁殖.     

褪黑素、谷胱甘肽对猪精液冷冻保存效果的影响

本试验旨在研究褪黑素、谷胱甘肽两种抗氧化剂对精子冷冻的保护效应。以成年杜洛克公猪为研究对象,在猪精液冷冻稀释液中先后单独、联合添加褪黑素、谷胱甘肽,解冻后精子质量通过检测活率、活力、顶体完整性、线粒体活性以及活性氧（ROS）含量来判定。结果表明：分别单独添加0.25mg/mL褪黑素、5mmol/L谷胱甘肽,或联合添加0.125mg/mL褪黑素和1mmol/L谷胱甘肽,均能减少精液冷冻过程中ROS的生成,显著提高冷冻精子解冻后的质量（P〈0.05）,其中联合添加效果显著优于单独添加效果。     

猪圆环病毒分子生物学研究进展

猪圆环病毒（PCV）是单链环状DNA病毒。它是近年来阻碍养猪业发展的重要传染病,因而成为各国学者的研究热点。本文就猪圆环病毒的基因组结构与功能,主要编码的蛋白质及其功能,分子生物学诊断方法等的最新研究进展作一综述。     

中草药防治猪传染性胃肠炎的研究进展

猪传染性胃肠炎是由猪传染性胃肠炎病毒引起的一种高度接触性肠道疾病。该病不仅可导致不同品种和各生长期的猪产生呕吐、腹泻和失水等临床症状,还具有传染性强、传播速度快的特点。因此,为了使猪传染性胃肠炎病得到有效的防治,文章主要从猪传染性胃肠炎的危害概况、中草药在猪传染性胃肠炎防治中的应用概况、中药防治猪传染性胃肠炎作用机理3个方面探讨了当前中草药防治猪传染性胃肠炎的研究进展,以期为兽医临床防治猪传染性胃肠炎提供理论依据。     

Relationship between sperm quality traits and field-fertility of porcine semen

An investigation involving seven boars, active in artificial insemination, and 1,350 multiparous sows was conducted at a private farm and aimed at examining the relationship between sperm quality traits and boar fertility in terms of farrowing rate and litter size. This experiment was done for 6 months. The semen samples were evaluated for subjective sperm motility and concentration. Ejaculates with at least 1 × 10⁸ sperm/mL and 70% sperm progressive motility were extended with a commercial medium to 30 × 10⁶ sperm/mL and used for artificial insemination (AI). AI dose was 100 mL semen containing 3 × 10⁹ spermatozoa. Aliquots of diluted semen were assessed for live morphologically normal spermatozoa (LMNS, eosin-nigrosin stain exclusion assay) and sperm chromatin instability (SCI, acridine orange assay). Farrowing rates according to different boar sperm varied (p < 0.001) from 59.3 to 88.92%. The mean values of LMNS (47.2~76.5%) and SCI (0.16~4.67%) differed significantly among boars. LMNS (r = 0.79, p < 0.05) and SCI (r = -0.90, p < 0.02) accounted for 62.2 and 81.7% of the variability in farrowing rates, respectively. After the combination of sperm traits, the relationship between percentage of LMNS with stable chromatin structure and farrowing rate was significant (r = 0.86, p < 0.05). The number of live piglets per parturition was not significantly correlated with sperm quality attributes. In conclusion, boar fertility after AI with freshly diluted semen can be predicted based on the evaluation of sperm morphology and chromatin integrity.     

Cryopreservation of stallion semen: Effect of adding antioxidants to the freezing medium on sperm physiology

Cryopreservation of stallion semen has not reached the level of efficiency and positive results described in other species. This is mainly due to the greater sensitivity of stallion sperm to the freezing process, showing higher rates of oxidative stress and plasma membrane damage, which trigger the activation of several cell damage pathways that ultimately culminate in DNA fragmentation and cell death. Therefore, finding molecules that improve the efficiency of this technique in stallion by preventing oxidative stress and cell damage is required. Thus, the aim of the present study was to evaluate the effect of adding three antioxidants (MnTBAP, NAC and FeTPPS) to the freezing medium on the quality and functional parameters of stallion sperm. Semen samples from three stallions frozen with the antioxidants were evaluated in two conditions: (a) adding the antioxidants before freezing, and (b) before and after freezing. Plasma membrane integrity, mitochondrial membrane potential, lipid peroxidation, intracellular ROS levels, membrane lipid disorder, DNA damage, sperm motility and binding to the zona pellucida were assessed. The results showed that MnTBAP was the antioxidant treatment that best controlled the oxidative stress process and post-thaw cell damage, showing higher plasma membrane integrity, mitochondrial membrane potential, sperm motility, number of spermatozoa bound to the zona pellucida of bovine oocytes and lower lipid disorder. Additionally, it was determined that a second post-thaw application of antioxidants is detrimental since induced higher cell damage and lower sperm motility, without showing any beneficial effect on the spermatozoa.     

Dihydromyricetin supplementation during in vitro culture improves porcine oocyte developmental competence by regulating oxidative stress

Dihydromyricetin (DHM), a dihydroflavonoid compound, exhibits a variety of biological activities, including antitumor activity. However, the effects of DHM on mammalian reproductive processes, especially during early embryonic development, remain unclear. In this study, we added DHM to porcine zygotic medium to explore the influence and underlying mechanisms of DHM on the developmental competence of parthenogenetically activated porcine embryos. Supplementation with 5 μM DHM during in vitro culture (IVC) significantly improved blastocyst formation rate and increased the total number of cells in porcine embryos. Further, DHM supplementation also improved glutathione levels and mitochondrial membrane potential; reduced natural reactive oxygen species levels in blastomeres and apoptosis rate; upregulated Nanog, Oct4, SOD1, SOD2, Sirt1, and Bcl2 expression; and downregulated Beclin1, ATG12, and Bax expression. Collectively, DHM supplementation regulated oxidative stress during IVC and could act as a potential antioxidant during in vitro porcine oocytes maturation.