公鸡精液稀释液的研究进展

随着现代养禽业的发展,种鸡普遍采用笼养,使家禽人工授精技术得到了广泛的应用,并使种蛋受精率显著提高,生产成本降低。由于家禽数量大,输精次数多,且公禽的采精量少,精子密度高,因此需要稀释。精液稀释后,能使精子均匀分布,精液量增加,保证每个输精剂量有足够的精子,便于给更多母禽输精,从而提高公禽的利用率,减少饲养成本,增加经济效益,同时精液只有经稀释处理后,才能进行有效的保存和运输。稀释液必须根据鸡精液本身的特性,从渗透压、pH值及稀释液所用化学试剂等诸方面进行考虑,国内外学者对鸡精液稀释液已进行了研究,本文就国内鸡精液…     

鸡精液稀释液研究进展

随着现代养禽业的快速发展,中国养禽的规模化和集约化程度越来越高,使家禽人工授精技术得到了广泛的应用。鸡的人工授精技术不仅显著的提高母鸡种蛋的受精率,也极大地降低了生产成本。尤其是采用鸡冷冻精液的人工授精可最大限度地利用遗传性能优秀的种公鸡,对保护品种资源有着重要的意义。由于家禽数量大,输精频率高,且公禽的采精量少,精子密度高,因此需要稀释。精液稀释后,能使精子均匀分布,精液量增加,保证每次输精有足够剂量的精子,便于给更多母禽输精,从而提高公禽的利用率,减少饲养成本,增加经济效益,同时精液只有经稀释处理后,才能进…     

家禽精液稀释液的发展

家禽精液是一种高度浓缩精子液,其容量小,为了增加精液的体积,提高单位体积中授精母禽数,常用稀释液对精液进行稀释。稀释后的精液,精子分布均匀,运输方便。在保存期间,稀释后的精液能维持和保护精子,最大     

鸡精子生理特性及稀释液的研究(摘要)

作者对鸡精子的生理特性进行了研究,并对27个鸡精液稀释液从受精率、孵化率、健雏率、活精子百分数、精子活力五个方面进行了比较、筛选。供试鸡为成年柯白公、母鸡。精液的 pH 值为7.2,冰点下降度为-0.660。鲜精分别用不同的稀释液按1:1的比例稀释,立即输精,试验组、对照组     

稀释液在人工授精中的应用

随着家禽人工授精技术的推广普及,精液稀释也被作为一门新型技术应用到生产中,众所周知,家禽精液有其精子浓度高、射精量低的特点,因此,有时需通过精液稀释扩充精液量,增加输精母鸡数,用稀释液稀释精液有以下好处:可使精子分布均匀,保证每个输精剂量中有足够的精子数,有利于精液保存,其有效成份能减轻外界不良刺激的影响;能够提高种公鸡的利用率,降低生产成本,提高经济效益. 试验目的: 1、观察稀释液对受精率的影响,从而选出最佳稀释液. 2、观察稀释液在不同间隔时间授精对受精率的影响.从而找出最佳授精间隔时     

湖羊精液多倍稀释受胎效果观察

精液多倍稀释配种技术是在原精液人工授精技术的基础上,选用以柠檬酸钠、葡萄糖、卵黄为主的稀释液进行稀释后输精。精液稀释可以提高精液使用效率,提高每次配种头数;稀释后精液形成精子的弱酸性环境,抑制精子代谢活动,降低精子能量消耗,抑制精液中有害微生物活动,补充适量营养和保护物质,延长精子寿命,达到受胎效果。     

不同稀释液2—5℃保存鸡精液的效果

许多研究表明新采集而未稀释的鸡精液,若在较高温度保存超过半小时就要影响其受精率。禽场进行常规人工授精工作时,总是每次采集数只公鸡精液就立即给母鸡输精。但是输精工作要求在下午进行,因为下午输精的受精率较高;而采精工作要求在早晨进行,因为多数研究认为清晨采精效果较好。因此,在当前家禽冷冻精液实际应用尚有许多困难的情况下,研究精液的液态保存,延长精子0℃以上保存活力和受精力的时间,显然有利于人工授精工作的安排和提高人工授精的工作效率,使人工授精在禽场条件下更为经济可行。此外,运送液态精液亦具有很大的实用价值。     

一种适用于羊的精液稀释液应用

正由于精液冷冻保存解冻后精子活力低、较难通过子宫颈进行深部输精、输精后妊娠率低等原因,使得解冻输精技术未能在生产上广泛使用,鲜精稀释后使用依然为当前羊人工授精的主流方式。精液在稀释过程中因成分发生改变会引起精子理化性质的变化,甚至给精子带来致命打击。因此,筛选出合适、方便且拥有实践应用价值的精液稀释液和稀释倍数,对提高羊人工授精技术的普及率和效率有重要的意义。现实生产中应用的稀释液有维生素B12注射液、鲜奶     

鸡精液稀释液储存时间与稀释比例对孵化率影响的研究

为解决鸡精液稀释液必须现配现用且受精率不稳定等问题,试验采用前期改进的YHFB鸡精液稀释液以及配套稀释技术,选取精子活力与精液密度中上等的石门土公鸡,分精液稀释1∶1、1∶2、1∶1(稀释液保存2个月)与原精液4组,进行等温及时稀释,稀释精液与原精液等体积对石门土母鸡进行人工输精,输精后24 h收集种蛋,检测孵化指标。结果表明:13个稀释组与原精液组的受精率没有显著差异(P0.05),1∶2组最高;21∶2组的受精蛋健雏率与入孵蛋健雏率均显著高于1∶1组(P0.05),也高于原精液组,但差异不显著(P0.05);31∶1(稀释液保存2个月)组,与1∶1组、原精组的孵化效果无显著差异(P0.05)。因此,前期研制的稀释液配方、保存方法与稀释技术能解决鸡精液稀释液必须现配现用等问题。     

不同精液稀释液对海扬黄鸡配套系亲本精液品质的影响

为探究鸡适宜的精液稀释液配方以及稀释液最佳保存时间,本实验采集50只海扬黄鸡精液,测定比较3种不同的精液稀释液(基础稀释液、BPSE稀释液、自配稀释液)稀释后体外不同存放时间(0.5、1.5 h)以及对自配稀释液在100℃灭菌和加双抗条件下不同存放天数(3、6 d)稀释后的精液品质。结果表明:存放0.5 h后,自配稀释液稀释后的精子活力较BPSE稀释液提高了2.29%(P<0.05),自配稀释液稀释后的精子活率较基础稀释液、BPSE稀释液分别提高0.65%(P<0.05)、0.66%(P<0.05);存放1.5 h后自配稀释液稀释精子活力较基础稀释液提高了4.61%(P<0.05),精子活率较基础稀释液和BPSE稀释液分别提高0.98%(P<0.05)、1.12%(P<0.05);BPSE稀释液稀释后的精子畸形率在存放0.5 h和1.5 h后均为最高;3种稀释液稀释后的精液在体外存放0.5和1.5 h之后,精液死精率均无显著差异,但在1.5 h时自配稀释液死精率最低;100℃煮沸和加双抗的稀释液在4℃冰箱中存放3 d和6 d后稀释的各精液品质指标间均无显著差异。综合上述,自配稀释液稀释后精液品质优于基础稀释液、BPSE稀释液,可作为海扬黄鸡的精液稀释液;煮沸或加入双抗的自配稀释液保存6 d之内对所测精液品质指标没有影响。     

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。     

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.