辽宁绒山羊公羊试情工作技术要点

只有做好辽宁绒山羊公羊的试情工作,才能将发情辽宁绒山羊发情母羊准确地挑选出来,并进一步确定最佳配种时间,保证冻精配种取得较好的受胎效果,具体要注意如下几点.     

山羊冻精的人工授精技术

1　冻精剂型山羊的冻精是从进口的优质山羊公羊身上采取精液 ,经过一系列处理后制作而成 ,目前有两种剂型 :细管和颗粒。制作好的冻精平时保存在液氮罐中 ,当人工授精时取出来解冻后输精。2　山羊的发情鉴定发情鉴定是人工授精的一个重要技术环节。通过发情鉴定可以判断出母羊发情是否正常 ,属于发情时期的哪一个阶段 ,以便于确定最佳的输精时间 ,特别是对那些发情时间持续短的母羊 ,更需要做好发情鉴定工作。山羊的性成熟一般是 6～ 8月龄 ,体成熟为 1岁左右 ,体重 2 5kg以上。只有达到体成熟后的羊只才开始初配。在山羊发情鉴定之前 ,必须…     

辽宁绒山羊母羊不正常发情产生的原因及防治措施

在正常情况下,辽宁绒山羊母羊的发情周期平均为21天,持续时间大约为1-3天,并且具有明显的、比较典型的外部发情特征。但是也有部分母羊,其发情规律不符合母羊正常的发情表现,生理、营养、疾病、年龄、应激等因素都可能导致这种现象的发生。不正常发情的母羊不管是冻精配种还是鲜精配种甚至本交配种,其受胎率都明显低于正常发情     

辽宁绒山羊母羊几种异常发情及其原因

在正常情况下，辽宁绒山羊母羊的发情周期平均为21d，持续1-3d，并且具有明显的外部发情特征。但是也有部分母羊，其发情规律不符合母羊正常的发情表现，生理、营养、疾病、年龄、应激等因素都可能产生这种现象。不正常发情的母羊不管是冻精配种还是鲜精配种甚至本交，其受胎率都明显低于正常发情配种的母羊。现将母羊几种不正常的发情与正常的发情情况比较如下，并对异常发情的产生原因进行分析。     

辽宁绒山羊母羊几种不正常的发情现象及产生原因

正常情况下，辽宁绒山羊母羊的发情周期平均为21d，持续时间大约1～3d，且具有明显的外部发情特征。但是，也有部分母羊的发情规律不符合母羊正常的发情表现，生理、营养、疾病、年龄、应激等因素都可导致母羊异常发情。不正常发情的母羊不管是冻精配种还是鲜精配种，甚至本交配种，其受胎率都明显低于正常发情配种的母羊个体或群体。现将母羊几种不正常发情与母羊的正常发情比较如下，并对异常发情的产生原因作以阐述。     

辽宁绒山羊冻精配种技术要点

应用优秀种公羊冻精配种，是提高辽宁绒山羊总体生产水平最快捷的途径。从近年来应用的效果来看，各地区冻精配种的受胎率变化幅度较大，一般为25.6％～86.8%。笔者根据多年应用冻精配种的经验，整理出辽宁绒山羊冻精配种的技术要点，供广大饲养户参考。1 根据母羊的年龄选择适当的输精方法     

绒山羊的发情及配种技术要点

为了摸索用人工方法辨别绒山羊母羊发情,探索其发情规律,并进行适时配种,对绒山羊公羊和母羊的性成熟、母羊发情特点、发情鉴定、发情控制、适时配种时间及配种方法进行了总结,以期为提高母羊受胎率和增加绒山羊养殖经济效益奠定基础.     

辽宁绒山羊母羊几种不正常的发情现象及产生原因

在正常情况下,辽宁绒山羊母羊的发情周期平均为21l天,持续时间大约为1-3天,并且具有明显的、比较典型的外部发情特征。但是也有部分母羊,其发情规律不符合母羊正常的发情表现,生理、营养、疾病、年龄、应激等因素都可能产生这种现象。不正常发情的母羊不管是冻精配种还是鲜精配种甚至本交配种,其受胎率都明显低于正常发情配种的母羊个体或群体。现将母羊几种不正常的发情与母羊正常的发情比较如下,并对异常发情的产生原因作一简要的介绍。     

皮下注射LH对绒山羊鲜精或冻精配种受胎率的影响

促黄体素(LH)为促性腺类激素药品。母畜在发情过程中,体内LH的分泌水平逐渐由低到高变化,一直达到最高值即LH峰值,引发母畜排卵。母畜排卵后,LH分泌水平很快下降。本试验的目的在于,在绒山羊发情后,人为地皮下注射LH药品,使LH峰值提前到来,使母羊提前排出卵子,从而使卵子与存活精子在可预定的时间段内相遇受精。在此基础上,比较鲜、冻精配种后的受胎率情况,为绒山羊人工授精工作提供技术依据。经试验证明,用LH处理绒山羊成年母羊后0.5～1h后进行鲜冻精配种,对鲜精配种受胎率没有显著的影响,对细管冻精配种受胎率有较大的影响,能显著提高绒山羊细管冻精配种的受胎率。     

一种用于绒山羊发情鉴定的新工具及使用方法

<正>目前,对绒山羊进行发情鉴定的方法较多,如外部观察法、阴道检查法、粘液镜检法等,但通过行为变化检查母羊发情存在工作量大、准确性差等问题,而阴道检查过多,会对母羊造成不良刺激并可能感染病菌,需要对羊进行保定,还存在人工劳动强度大、检查速度慢的问题。粘液镜检的准确性较差,不能适合细管冻精配种的技术需要。针对上述现状,笔者通     

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.