牛精液冷冻技术应用研究进展

在简要介绍牛精液冷冻技术发展历史的基础上,分析了牛冷冻精液的现状和影响牛冷冻精液受胎率的主要因素,指出了我国牛冷冻精液存在的问题,应加强精液冷冻机理、精液冷冻保护剂、精子质量评估和分离精子的冷冻保存等方面的研究,最后展望了牛冷冻精液的发展前景。     

绵羊精液冷冻保存研究进展

绵羊精液保存技术目前虽然已进入生产应用阶段,但冷冻精液人工授精受胎率低仍是限制绵羊冷冻精液进行生产推广的重要因素。目前,对于绵羊精液冷冻的研究主要集中在冷冻稀释液组分和冷冻程序等方面。文章针对国内外有关绵羊精液冷冻保存稀释液、冷冻程序、解冻方法和冷冻损伤等研究进展作一综述,旨在对今后精液冷冻保存研究提供一定的参考。     

影响绒山羊冻精质量de几个冷冻技术环节

影响绒山羊冻精质量的技术环节,主要由冷冻温度、降温速度以及冷冻容器的选择等构成。1 冷冻温度冷冻温度影响精液冷冻后的存活率、顶体完整率、受精率等生物参数。冷冻后精子存活率的高低通过低温温度计测定精液在冷冻容器中冷冻的变化来反映精液速冻温度的变化曲线。尤其冻制细管精液时如果不考虑冷冻容器和冷冻环境的温度及每批精液冷冻总容量,而是盲目地根据精液和冷源的距离决定冷冻温度是不准确的,这样导致精子活率低而达不到国标要求。冷冻精液是一项动物繁育技术,如果不用科学仪器在生产中进行监测,不遵循先进的冷冻程序是很难保证…     

影响犬精液冷冻效果的因素分析

精液冷冻是影响犬人工授精技术的关键环节,由于冷冻效果不稳定,冻后精子活力差,造成人工授精成功率低,平均窝产仔数少,影响到该技术在国内的广泛使用。犬精液冷冻是一项系统的技术,影响犬精液冷冻效果的因素也是多方面的。综述了精液冷冻保护剂、质膜保护剂、抗氧化保护剂、冷冻程序和冷冻方法等因素对犬精液冷冻效果的影响。     

牛细管精液冷冻温度曲线的研究

牛冷冻精液精子复苏率的高低与原精质量、精子耐冻性、稀释液种类、稀释方法及精液冷冻和解冻速度等因素有关。其中，精液在冷冻过程中温度变化曲线是影响精子复苏率高低的重要因素之一。研究细管精液在不同条件下冷冻，精液温度变化曲线及精子复苏率变化的规律，优选出细管精液最适宜的冷冻温度曲线，可以为提高牛冷冻精液质量提供重要保障。     

循化县应用颗粒冷冻精液技术和细管冷冻精液技术的回顾性研究

对1994-2003年间采用颗粒冷冻精液技术和细管冷冻精液技术对10037头(次)当地母牛进行了人工授精的情况进行回顾性研究,结果发现：细管冷冻精液技术的授胎率比颗粒冷冻精液的高13．64％;与颗粒冷冻精液技术相比较,细管冷冻精液技术有省时、省力、操作简便,所用设施投入少等优点,更适合农区基层的黄牛改良工作。     

猪冷冻精液技术在规模猪场的应用

比较猪冷冻精液和常温精液对母猪繁殖性能的影响,发现使用冷冻精液配种的母猪分娩数、窝产仔数、窝产活仔数均低于使用常温新鲜精液配种的母猪,且冷冻精液配种母猪的死仔数偏多,但差别不大。因此,冷冻精液虽然具有储存时间长、运输方便等特点,但在使用冷冻精液时,需要注意精液的解冻方法和输精技术,以提高母猪的受胎率和产仔数。     

对牛冷冻精液微生物检测培养基种类培养时间的探讨及控制细菌数的措施

牛冷冻精液在采集、稀释、分装及冷冻等生产过程中都有可能被污染，并且有大量资料表明许多细菌性及病毒性传染病都可能通过精液而传播，因此，对牛冷冻精液的微生物检查是冻精质量检测的重要指标之一。我国《牛冷冻精液国家标准》中明确规定：牛冷冻精液解冻后的精液，无...     

绵羊冷冻精液研究进展

随着肉羊产业化、工厂化的发展,冷冻精液人工授精技术亟待应用于生产中.绵羊精液冷冻保存技术虽然得到了快速发展,但目前仍处在试验研究或小范围的应用阶段.因此,绵羊精液冷冻技术还需要深入、系统的研究.文章从绵羊精液冷冻保存稀释液中的添加剂、冷冻速率、冷冻-解冻对绵羊冷冻精液品质的影响,精液输精对受胎率的影响等方面进行了综述,为精液冷冻保存研究提供一定参考.     

细管精液冷冻设备冻精方法的创新

自从应用牛的冷冻精液技术以来,为了提高冷冻精液的质量,研究人员在精液的稀释液配方、精液的冷冻方法及冻精1剂型等方面进行了大量研究。仅冻精的制作设备和方法探讨上,就经过了用铝锅等简易装置盛装液氮,在氟板或铜网上冷冻颗粒精液;使用冷冻槽或广口液氮罐,在静止的液氮蒸气     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

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.     

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。 …