鹅人工授精的优点及注意事项

<正>我国鹅人工授精工作起步较晚,但这项技术随着水禽业的集约化生产而逐渐受到重视,现已成为现代养鹅业中一项先进的繁育技术。在市场竞争日益激烈的鹅业生产中,应用人工授精技术的意义十分重大,它可以提高鹅的生产性能、节省饲料、降低生产成本、促进品种改良、增加经济效益,其中最明显的是提高种蛋受精率和受精蛋孵化出雏率。     

鹅种蛋孵化技术

种蛋孵化是鹅业生产的关键环节，是养鹅生产的基础。种蛋孵化率高低除了和孵化技术直接相关外，还间接的与种蛋质量密切相关，如种蛋来源（种鹅的饲养、公母比例、防疫卫生等）、保存时间、蛋重、蛋形、蛋壳质量和清洁度等，为了提高鹅蛋的孵化率必须全面考虑以上因素。     

种鹅人工辅助配种的技术措施

在鹅业生产中．种鹅的产蛋率和种蛋受精率低是制约鹅业发展的关键因素。在人工授精技术尚未有效普及应用的情况下．采用人工辅助配种技术是解决这个问题的良好途径。     

太湖鹅的人工授精技术

我国鹅的人工授精技术起步较晚，但这项技术随着水禽业的集约化生产而逐渐受到重视。在市场竞争日益激烈的鹅业生产中，降低生产成本，特别是种鹅的饲养成本，对增加经济效益尤为重要。采取人工授精可使鹅的配种比例提高３倍左右，也就是说可以减少３／４的种公鹅，大大提高优秀种公鹅的利用率，并可减少因自然交配时生殖器官疾病的传染和提高种蛋的受精率，增加养鹅厂生产的经济效益。一、种公鹅的选择与训练采精训练前１５～３０天，将体格健壮、性欲旺盛的备用种公鹅和母鹅分开饲养。训练时剪去公鹅泄殖腔周围直径５～７厘米的羽毛，…     

开产前种鹅的选留与饲养管理

随着市场对鹅综合产品需求的增加,养殖数量不断增加,种鹅养殖在整个养殖中效益提高明显.养鹅已成为农民增收、农业增效的重要项目.随着养鹅业的迅速发展,种鹅数量不断增加,种鹅的选留与繁殖扩群已成为发展养鹅业的重要工作.开产前选留种鹅,加强饲养管理,可以提高鹅群开产整齐度,提高种蛋受精率和种蛋质量,同时淘汰不良个体,降低养殖成本.选择种鹅要针对品种特点,确定选育目标,与此同时,注意加强鹅群的饲养管理,以使其生产潜力充分地发挥出来,提高鹅群整体的生产性能.     

规模化种鹅生产中种蛋受精率的影响因素调查分析

近年来鹅业发展势头强劲,尤其是随着鹅"反季节繁殖技术"的推广与应用,促进了养鹅业的产业化发展.但在发展过程中,许多单位在最初获得良好回报之后,出现了种鹅繁殖性能随着生产规模扩大而下降,主要表现为在春夏季种鹅产蛋率下降、种蛋受精率低下、受精蛋孵化率降低的问题,甚至还出现采用"反季节繁殖"技术造成亏损的现象.     

提高雏鹅品质的综合性措施

节粮型的养鹅业在畜牧业结构调整中，起着十分重要的作用。人们对鹅产品的接受，客观上提供了养鹅业发展的市场空间。然而由于种鹅繁殖力低，导致生产效率低下。因此，搞好种鹅蛋的孵化工作十分重要。为此，笔者总结了在“机械孵化（第１～２１天）＋摊床出雏”方式下。对种鹅蛋施以“变温、高湿、增氧、微震”措施，能显著提高孵化效果和雏鹅质量。现将有关综合措施简介如下。 一、获取优良种蛋 １．种蛋应来自品质优良、健康的种鹅群。 ２．应加强种鹅饲养，根据不同品种和生理阶段，供给营养全面、平衡的饲料。 ３．确定合适的公母比例，…     

提高种蛋受精率的技术措施

近年来,随着农业产业结构的调整,在我国广大农村地区,养鹅业蓬勃发展,由过去松散的小农生产逐渐过渡到规模化养殖,尤其是种鹅的饲养量逐年增加,提高种蛋受精率是发挥养鹅经济效益的重要环节.笔者通过多年来的生产实践认为,提高鹅蛋受精率必须做好以下几个方面的工作.     

提高种鹅产蛋率和蛋受精率

在鹅业生产中,鹅的产蛋率和种蛋受精率低是制约鹅业发展的关键因素。在人工受精技术尚未有效普及应用的情况下,采用人工辅助配种技术是解决这个问题的良好途径。     

种鹅血液内毒素水平与产蛋、受精率及胚胎成活率的关系

在当前的种鹅生产尤其是反季节生产中,种鹅生产性能(产蛋率、受精率和胚胎成活率)偏低,严重制约种鹅生产力提高和养鹅业的发展,其中内毒素可能是主要影响因素之一。试验为了更好地探讨这一关系,采集了广东省内不同地域的5家规模化鹅场,在进行反季节生产阶段对种鹅的产蛋率、受精率和胚胎成活率以及种鹅血浆中内毒素水平进行测定。结果表明:除产蛋数外,规模化种鹅场的种蛋受精率和胚胎成活率呈现一致的变化,而与种鹅血浆中内毒素水平呈现相反的变化。说明在中国南方地区进行种鹅反季节生产时,种鹅受精率和种蛋胚胎成活率的偏低与种鹅血浆中内毒素的水平直接相关,即种鹅机体内的内毒素含量能直接影响到种鹅的繁殖性能,是影响种鹅反季节生产水平的主要原因之一。     

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。     

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.