褪黑素影响动物繁殖性能的研究进展

褪黑素是一种由哺乳动物松果体分泌的神经内分泌胺类激素,通过其高亲和性膜受体的参与调控动物生理节律、季节性繁殖、睾丸及卵巢功能等生理过程。本文就褪黑素的相关特性及其对动物繁殖性能的影响进行综述,为褪黑素在动物生产中的广泛应用提供参考。     

光照对猪生产性能的影响

光照对猪生产性能的影响田允波（云南农业大学动物科技学院昆明，６５０２０１）随着工厂化养猪业的兴起，猪舍小气候的控制愈加显得重要。光照是影响家畜生长、繁殖的主要环境因素之一。目前在养猪生产上，猪的光照管理未受到足够的重视，而合理的光照制度对提高猪的生产...     

人工LED光源在猪场养殖的应用研究

<正>随着工业化养猪业的兴起和非洲猪瘟等疾病的发生,猪场空气、光照、温湿度等环境因素受到更多关注。但光照对猪的影响往往被忽视。其实光有很好的杀菌效果,而且光能影响动物的新陈代谢、日常行为、生长周期、繁殖性能等,与动物生长发育有直接关系。通常情况下,猪舍光照分为自然光照射和人工补光两种,随着猪场规模化发展及猪瘟的影响,大跨度、全封闭式猪舍越来越多,高密闭性猪舍光源基本依赖于舍内人工照明系统。如何利用LED人工光源调节猪的生长节律,提高生长速率,降低死亡成为行业关注热点。     

种公禽繁殖系统对光要素的应答机制研究进展

光照是生物体重要的生活环境因素之一。禽类具有优越的感光机能,光线通过其光感受器被感知,并转变为生物学信号,从而对生长发育、繁殖和行为等方面产生影响。在现代养禽业中,人工优化光照环境已成为提高动物生产性能的一项重要手段。近年来,随着种用母鸡笼养、人工授精技术的广泛应用及精液处理、包装和存储技术的发展,在家禽养殖中,也逐步将种公禽单独饲养。研究光照对种公禽繁殖性能的影响,一方面可以进一步解析种公禽繁殖系统对光要素的生物应答机制,另一方面可为生产中采用精细化的光照条件提高种公禽繁殖效率提供科学依据。笔者就禽类的光感受器,参与光-性信号传导的激素,以及光照节律、光照强度和光波长对种公禽性成熟和繁殖性能的影响等方面的研究进展进行综述,以期为其在生产中的应用奠定基础。     

光周期对牛生长、胴体品质和采食的影响

光照不仅对动物繁殖性能有显著影响,对动物的生长发育等也有一定作用。长期以来,光照控制一直是禽类生产中的一项重要措施,但至今也还没有确定适合不同品种、生理阶段和生长需要的光照制度。在牛的生产中,尽管光照控制显得不像鸡那么重要,但在冬季舍饲和集约化生产的条件下,光照对牛生产性能(如体增重和产奶量)的影响日益受     

养猪过程中的生物安全——光照管理

猪不同生长阶段或不同生理阶段受环境因素的影响很大,光照因素是重要的环境因素之一,与猪的生长发育、育种繁殖以及生产性能的发挥息息相关,应引起养猪管理者的高度重视。     

光照制度在养猪生产上的应用研究进展

养猪生产中,合适的光照长度及光照强度对猪只生产性能的发挥有相当大的影响,最新的研究表明光照长短会影响仔猪的免疫功能同时对母猪的繁殖性能及公猪的繁殖性能都有很大的影响,而且合理的光照有助于生长肥育猪生产性能的发挥,提高饲料利用效率。文章就光照制度在养猪生产上的应用研究进展进行综述。     

光照对猪生长发育、繁殖性能及免疫力的影响

光照直接影响猪的生长发育、繁殖性能和机体免疫力。适宜的光照时间和强度能够提高猪的健康状况及生产水平,从而提高养猪产业的经济效益。但是,在当前的养猪生产中,还没有制定相应的光照制度,对光照的重视度相对缺乏。论文主要综述了光照对种公猪、种母猪、仔猪以及生长育肥猪等各个阶段生长发育、繁殖性能以及免疫力的影响,为科学利用光照时间和强度提高养猪生产水平提供重要的理论基础。     

酵母硒在猪生产中的应用

硒是动物机体必需的微量元素，参与体内许多重要的生理活动，而酵母硒以其易吸收及毒性小等特点受到广泛关注。文章主要介绍酵母硒在猪生产中，对猪生产性能、抗氧化能力、免疫系统及繁殖陛能的影响。     

光照制度对家兔繁殖性能的影响

光照是影响家兔生长繁殖的主要环境因素之一,与家兔的生理机能和生产性能的变化密切相关,适宜的光照制度是家兔正常养殖生产过程中必不可少的环境条件.本文总结概括了在家兔的生产过程中光照时间、光照强度、光色(波长)和光照周期等不同光照条件的变化对家兔生理机能及繁殖机能的调控和影响,并在此基础上对相关光照控制制度的研究前景进行了...     

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.