精液解冻时抗冻剂的保护特性

在养牛业中已广泛利用公牛的冷冻精液,但还需要经常研究和改进精液解冻的方法。冷冻保存精液的效果不仅与冷冻有关,也与解冻有关。研究最适宜的解冻条件,是提高精子质量的重要问题,因为,在解冻时精子细胞也容易受损伤。已有的文献一般只报道抗冷冻剂在冷冻过程中的保护作用。本研究是为了弄清用不同抗冻剂保存的冻     

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。     

牛精液冷冻保存技术研究进展

牛精液冷冻保存的应用促进了我国牛人工授精技术的发展,通过冷冻保存可以延长精液保存时间,扩大良种公牛精液的使用范围,提高种用价值,加速品种的育成和改良步伐。本文从牛冷冻精液稀释液的成分,卵黄稀释液与无动物源性稀释液的发展,冷冻保护剂对精子冷冻效果的影响,抗氧化剂和抗生素在牛精液冷冻保存中的应用等方面进行了综述,旨在为今后的牛精液冷冻保存研究工作提供一定的参考。     

不同解冻液对精子呼吸强度的影响

呼吸是精子重要的生命现象之一。当精液中有氧存在时精子就通过呼吸,氧化代谢精液中可以利用的营养物质。本试验测定了4种不同解冻液所解冻公牛冻精中精子的耗氧量,结果表明,不同解冻液对精子的呼吸强度有显著影响。一、材料与方法 (一)解冻液的组成见《中国奶牛》,1991年,第4期。 (二)精液山西省家畜精液冷冻中心HB63号公牛颗粒冻精。     

山羊精液冷冻保存稀释液添加剂研究进展

精液冷冻保存技术是山羊繁育体系的重要组成部分，可以有效保存优质种质资源并加速山羊育种工作进程。山羊精子在冷冻过程中会受到氧化应激、冷应激等不利因素的损伤，导致山羊精子解冻后质量和人工授精受胎率较低，大大限制了山羊冻精的应用。因此，本文综述了近年来在山羊冷冻保存稀释液中添加抗氧化剂、糖类、脂肪酸等添加剂对山羊精子解冻后质量的影响，以期为山羊冷冻精液研究提供理论参考。     

金华猪精液冷冻保存技术研究

本试验用0.5 mL细管作为冷冻载体对金华猪精液进行冷冻保存研究,比较3种冷冻稀释液及不同冷冻方法、解冻程序对金华猪精液冷冻的效果,以解冻后的精子活力、畸形率和质膜完整率为判定指标。结果表明:Ⅱ、Ⅲ号冷冻稀释液处理组解冻后精子的活力、畸形率和质膜完整性都明显地高于Ⅰ号冷冻稀释液(P0.05);Ⅱ号冷冻稀释液和Ⅲ号冷冻稀释液处理组之间没有明显差异(P0.05)。采用程序冷冻仪冷冻法,使用Ⅲ号冷冻稀释液冷冻保存精子,并在60℃,8 s条件下水浴解冻精子后,精子活力和质膜完整率最高分别为42.3%和50.3%,畸形率最低为17.7%。因此,采用程序冷冻仪冷冻法,使用Ⅲ号冷冻稀释液,在60℃,8 s条件下水浴解冻方法较为适合0.5 mL细管金华猪精液冷冻保存及解冻。     

种公牛精子耐冻性对比试验

精子耐冻性一般用冷冻精液解冻后精子的复苏率和精子顶体完整率来比较.对于种公牛,冷冻精液解冻后精子的复苏率和顶体完整率越高,其耐冻性越好.为探讨种公牛品种、年龄、个体等因素对耐冻性的影响,进行了试验观察.     

冷冻保护剂对家畜精液冷冻保存的研究进展

家畜精液冷冻保存可以实现在不同时间、不同地点的人工授精,能有效提高优良种公畜的利用率,扩大其基因传播范围,同时也是家畜遗传资源易位保存的主要方法之一。在精液冷冻保存过程中,选择合适的稀释液成分对解冻后精子品质的影响十分重要。精子对低温非常敏感,在稀释液中加入冷冻保护剂可有效提升精子解冻后活力。文章综述了近几年渗透性冷冻保护剂(甘油、乙二醇、二甲基甲酰胺、二甲基乙酰胺、二甲基亚砜)和非渗透性冷冻保护剂(卵黄、大豆卵磷脂、蔗糖、脱脂乳)在猪、牛、羊、鸡、兔以及骆驼上的应用与研究,旨在为进一步深入研究家畜精子冻融损伤机制提供理论依据。     

猪精液超低温冷冻保存研究进展

猪人工授精(AI)技术已经广泛应用于畜牧业生产,但精液来源基本是17℃保存的新鲜猪精液,不利于精液长期保存和猪种资源保存。超低温冷冻保存技术是猪精液长期保存最有效的方法,冷冻精液可以实现不同地区、不同国家优良种猪精液间的交流,从而大大提高猪种资源的利用率,但冷冻解冻后的精液质量较差,受胎率、窝产仔数远低于鲜精,极大地限制了猪精液冷冻保存技术的广泛应用。本文综述了猪精液冷冻保存研究概况、猪精液冷冻损伤机理和猪精液冷冻保存影响因素,以期为猪精液超低温冷冻保存研究提供新的思路和方法。     

不同甘油浓度对兔精液冷冻保存的影响

本试验以不同浓度甘油对家兔精液冷冻保存的影响为研究目的,以柠-葡-卵基础液于三种浓度(6%、8%、10%)的甘油相配伍做为冷冻保存液对精液进行稀释,平衡,冷冻,解冻等处理,从而确定兔精液冷冻保存的最佳甘油浓度,得出如下结论:冷冻保护液中添加浓度为6%的甘油时,对精液进行冷冻保存、稀释、平衡,解冻后的精子活率与浓度为8%,10%的甘油冷冻效果比较差异显著.     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。