不同冷冻曲线对种公牛精液冷冻质量的影响

种公牛精液的冻后活力是评定冷冻精液品质好坏的重要指标之一,也是影响牛人工授精受胎率的重要因素.影响冻精解冻后活力的因素包括种公牛个体差异(鲜精品质、耐冻性)、稀释液(甘油浓度、稀释液成分)、生产工艺(稀释方法、平衡、冷冻方法、冷冻曲线)和解冻方法等.而冷冻速度,即精子通过对细胞产生致死性伤害的0～-60℃温度区的速度,是决定冷冻精液冻后品质好坏的关键所在.     

茸鹿人工授精的研究

本研究包括对茸鹿(主要是梅花鹿和马鹿)采精,精液冷冻保存和输精三个部分。从1977年开始用自制的电刺激采精器(交流型),在7种动物中采精42次,并用自己筛选和研制的精液稀释液与保存液配方:特研Ⅰ号和Ⅱ号,液氮冻存茸鹿精液389安瓿(梅花鹿238安瓿,马鹿103安瓿,驯鹿42安瓿,杂种鹿6安瓿),精子活力保存2年以上者仍在0.3以上。用冷冻精液给茸鹿输精,1979年获1只梅花鹿仔鹿(共输4只),1980年又获9只马鹿仔鹿(共输25只,受胎率为36％)。     

藏獒精液冷冻过程中pH值及甘油对其活力的影响

为探讨pH值和甘油对藏獒精液冷冻保存前后精子活力的影响,筛选6条种公藏獒在其繁殖季节(9~12月份)以不同pH值梯度(5.5,6.0,6.5,7.0,7.5)稀释液和不同甘油平衡时间(10,20,30,40,50,60,70,80,90 min)对藏獒精液进行冷冻,检查精子活力变化。结果表明,在藏獒精液冷冻过程中,pH值为6.5的稀释液中精子在冷冻前后有较高的活力;甘油平衡时间对藏獒精液活力有较大影响,冻前精子活力随甘油作用时间而下降,在甘油平衡时间为20 min所得藏獒冻后精子活力效果较好。     

鸡精液DMA颗粒冷冻与解冻方法研究

鸡精液DMA颗粒冷冻技术方法简单,但还很不稳定。试验采用3种颗粒冻精制作以及2种冻精解冻技术对黑丝羽乌骨鸡精液冷冻技术进行了研究。结果表明:1)非浮体方式当温度设定为-40至-170℃的较宽范围时,温度对活力影响较大,滴冻起始温度与持续熏蒸时间二者交互作用下,对活力影响差异显著(P0.05);浮体方式当温度范围为-100℃至-130℃,时间对活力影响较大,滴冻起始温度与持续熏蒸时间二者交互作用下,对活力影响差异不显著(P0.05)。2)采用颗粒直接滴冻技术,稀释后平衡10min与平衡20min组冻精解冻后活力没有显著差异;解冻温度为40℃和50℃较好,两组之间活力无显著差异;采用恒温板解冻,每次解冻1颗的活力显著高于每次解冻3颗的活力。因此,黑丝羽乌骨鸡精液,采用DMA为冷冻保护剂,稀释后平衡10min,添加冷冻保护剂后直接滴冻,50℃恒温板解冻能获得较好的冷冻效果。     

湖羊精液冷冻对受胎率的影响

本试验利用前期筛选的湖羊精液冷冻稀释液及冷冻保护剂制作湖羊冻精,对比冻精和鲜精的精子活力和顶体完整率。同时,对40头初产母羊和40头经产母羊进行同期发情处理,然后分组进行鲜精和冻精输精试验,跟踪受胎率。结果表明,冻精的活力和顶体完整率分别为0.396和49.2%,显著低于鲜精;初产母羊和经产母羊的冻精受胎率分别为41.7%和33.3%,也显著低于鲜精。说明湖羊精液冷冻对湖羊精子质量和母羊受胎率都存在显著影响。     

2种稀释液对公猪精液冷冻保存效果的影响

试验为探究2种不同冷冻稀释液对公猪精液稀释冷冻效果的影响。试验采用手握法采集同一头公猪精液,将采集的精液分为2组,进行液氮熏蒸制作细管冻精,分别使用Ⅰ号冷冻稀释液和Ⅱ号冷冻稀释液对猪精液进行冷冻保存,24 h后检测2种冷冻稀释液细管冻精的活力。结果显示,Ⅰ号冷冻稀释液冷冻解冻后的精子活力显著高于Ⅱ号冷冻稀释液(P0.05),同一种稀释液距液氮面5 cm进行熏蒸冷冻的效果较距液氮面4 cm冷冻效果好,但差异不显著(P0.05)。研究表明,利用Ⅰ号冷冻稀释液在距液氮面5 cm处进行液氮熏蒸冷冻可获得较好的公猪冷冻精液。     

组织培养液M199在庆阳驴细管精液中的应用

为了研究M199对庆阳驴细管鲜精和细管冻精活力及保存时间的效果影响。在鲜精稀释液中,添加不同浓度的M199,在低温保存下,观察不同时间段精子活力;在冻精稀释液中,添加1%的M199,采用液氮熏蒸制作冻精,解冻后观察冷冻效果。结果显示,在低温保存中,稀释液中添加1%的M199,48h后精子活力仍然在0.35以上,与其他试验组和对照组差异极显著(P0.01)。在冻精稀释液中添加1%的M199,试验组与对照组冻后精子活率分别为30.83%和31.33%,两者之间差异不显著(P0.05),但试验组精子有效存活时间显著高于对照组。通过在庆阳驴精液稀释液中添加M199,均能很好的延长精子保存时间。     

不同精液冷冻程序对杏花鸡精液冷冻效果的影响

本试验选择BPSE(Blesville Poultry Semen Extender)作为精液稀释液,以二甲基乙酰胺(dimethylacetamide,DMA)和乙二醇(ethylene,EG)2种试剂作为抗冻剂,分别以不同的质量浓度进行组合,对杏花鸡精液冷冻保存的平衡时间、冷冻方式和解冻温度以及时间等影响精液冷冻效果的关键因素进行了研究。结果如下:(1)质量浓度分别为4%DMA和6%EG的抗冻剂对精液保护效果较好,精子冻后活力分别为0.466和0.464,两者之间差异不显著;(2)选择质量浓度为6%EG为抗冻剂,平衡8 min后的精子活力最高,为0.542;(3)在(2)的基础上,选用颗粒冷冻和细管冷冻2种方式冷冻,分别在水浴锅里以40℃、55℃、70℃3个温度解冻。结果表明,用颗粒冷冻在55℃水浴锅里解冻的精子活力最高,为0.482;(4)采用颗粒冷冻和细管冷冻2种方式对新鲜精液冷冻解冻后与新鲜精液一起进行人工授精,捡蛋入孵后统计受精率,细管冷冻、颗粒冷冻以及鲜精的受精率为0、0和92.52%。结论:在本试验中,以6%EG为抗冻剂,在5℃下平衡8 min,用颗粒冷冻的方法在55℃恒温水浴箱内解冻可以使解冻后的精子达到最大的存活率;授精试验效果不佳,表明该程序虽然可以使精子存活,但是对精子有损害作用。     

蓝狐细管冻精的研究

实验对蓝狐细管冻精的冷冻工艺进行了筛选。结果表明:4种以Tris-柠檬酸-甘油稀释液作为细管冻精稀释液效果良好,其中以葡萄糖代替果糖的A1配方及稀释方法效果最佳。常温和冷冻保存中结果发现,虽然乙二醇毒性较大,但含有6%乙二醇的防冻剂的精液解冻后活率最高。冻精平衡以0￣5℃和2 h为宜,初冻温度以-110￣-130℃的冷冻速度最好。解冻时,以38℃水浴中存活指数最高。冷冻过程使精子活率、畸形率、顶体完整率等指标受到明显影响。以A1为冷冻液的冻精人工授精受孕率为73.81%,每胎产仔数为5.81,与鲜精人工授精的结果差异显著(P<0.05)。     

不同类型稀释液对驴冷冻精液品质的影响

[目的]:对比分析各类型稀释液对驴冷冻精子活力、畸形率的影响,根据冻精解冻效果,筛选出适合驴精子冷冻的最佳稀释液,最适宜稀释比例,为驴冷冻精液研发提供参考。[方法]:实验共计14 d,采集6头种公驴精液,每份原精均分为3等份,分别用3种稀释液稀释,从而选取最优稀释液;按1∶0.75、1∶1.5、1∶3、1∶6不同比例混合最优稀释液与蒸馏水,每份原精均分为4等份,对应不同浓度稀释液分别进行稀释、封装、冷冻,检测冻精子活力和畸形率。[结果]:普蒂迪尔公牛稀释液、特里拉迪尔公猪稀释液、仙女座马稀释液三种稀释液中,特里拉迪尔公猪稀释液在配伍比例(稀释液与蒸馏水比值)为1∶3时,冷冻过程中能明显降低驴精子的畸形率,提升精子活力,能最大限度保存驴精子生殖功能。     

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。     

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。     

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。     

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。     

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.     

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.