滞育卵冷藏浸酸试验

<正> 滞育卵冷藏浸酸法,也叫黑种冷藏浸酸法。是对已超过冷藏浸酸法施行适期的蚕种采取应急措施。在生产中有一定的实用性。滞育卵浸酸后,冷藏时间多长能完全解除滞育,达到一定孵化率?我场就这个问题进行了试验。采用浸酸后冷藏再浸     

提高蚕种冷藏浸酸质量关键技术的探讨

<正>春制蚕种冷藏浸酸主要供应秋用蚕种,实际生产中冷藏浸酸蚕种容易出现孵化不良、死卵多等问题,提高冷藏浸酸蚕种的孵化率,确保秋用蚕种质量,是蚕种工作者研究的重要课题。 1 蚕种冷藏浸酸的生物学原理分析冷藏浸酸蚕种在产卵后25℃左右保护约2d后开始冷藏,冷藏过程中蚕卵的滞育进程虽然迟缓下来,但不停止,至少在冷藏开始后20-30d内蚕卵没     

冬季收蚁的滞育蚕卵孵化法实验

冬季收蚁的滞育蚕卵孵化法实验徐厚镕（安徽农业大学轻工学院蚕桑系２３００３６）春制滞育蚕种，需要在夏秋季使用时，生产上一般采用冷藏浸酸法，即：滞育卵从母蛾产下后在，２５℃温度中保护３天左右，卵色变为赤豆色，入库冷藏。根据生产需要，可用卵色深浅不同、冷藏...     

桑蚕“两广二号”蚕种冷藏试验

本文对“两广二号”蚕种用三种冷藏方法进行了比较试验，结果表明：复式冷藏法有效期限前后两期冷藏200-220天以内，单式冷藏法冷藏120-200天，滞育卵冷藏浸酸法冷藏100-180天，可得到有实用性价值的蚕种，复式冷藏法对延长滞育蚕种的冷藏有显著效果，如果适当批迟中间感温时间还可延长蚕种有效冷藏期。     

即时浸酸蚕种浸酸前后冷藏技术体会

<正>延长即时浸酸种浸酸后冷藏的有效期限,以利调节蚕种的供应时期,提高蚕种的使用率已是蚕种生产的成功技术了。但是,笔者通过蚕种冷藏多年的生产实践,就如何延长即时浸酸种浸酸前的冷藏抑制和浸酸后的乙胚子、丙胚子、丁胚子不同发育阶段的冷藏抑制技术谈几点体会。1掌握浸酸适期即时浸酸时期适当与否,对蚕种孵化及死卵发生有密切的关系,浸酸过早,易发生死卵;过迟,蚕卵的滞育性趋向稳定,会引起孵化不齐甚     

蚕种冷藏加工的实践与体会(下)

<正>4蚕种人工孵化技术要点为打破春制越年种进入滞育状态,以解决当年夏秋用种需要,在产卵后适当时间给予蚕种物理或化学刺激,并结合冷藏低温处理打破卵的滞育状态,恢复发育机能,直至正常孵化,这就是人工孵化。人工孵化法种类很多,目前生产上推广使用的是盐酸孵化,依处理时期不同可分为即时浸酸、冷藏浸酸、随时冷藏浸酸孵化等,前两种用得较多。4.1即时浸酸4.1.1加温即时浸酸     

即时浸酸种延长冷藏抑制有效期限的研究

用即时浸酸种冷藏的办法来调节孵化日期,一直都在生产上沿用,但冷藏时间一般在20天以内,按规定冷藏期限超过20天的蚕种不能发放,这样就容易造成蚕种浪费或蚕种供应受到限制,对生产很不利。那么这种实用期限能否再延长呢?在日本有即时浸酸后冷藏卵用氯化钠水溶液浸渍和给冷藏卵补充水分办法延长冷藏期的试验报导。在我国也有即时浸酸种(春制种)浸酸后入库冷藏(3～4℃),能延长冷藏抑制有效期限的研究报导。延长即时浸酸后冷藏抑制的期限     

提高滞育卵冷藏漫酸孵化率技术的探讨

本通过总结近几年国内外同行及本单位对滞育卵人工孵化的研究试验和实践，探索出提高滞育卵冷藏浸酸孵化率的部分技术要领，认为二化性品种滞育卵进入滞育时间在20日以内，采取浸酸—冷藏—浸酸形式，如冷藏时间在40天以上，配合补催青黑暗处理，其孵化率基本可达到生产上的要求，且对蚕体体质无不良影响，如冷藏时间在50天以上可在生产上放心使用。     

谈提高冷藏浸酸蚕种孵化率的体会

<正>目前我省所生产的蚕种80%来自农村原蚕点,由于原蚕点生产条件、技术条件、管理水平等客观因素的制约,时有蚕种分段不清,卵龄开差大,脱落卵多、不良卵多,杀蛾时间不规范、产卵室温度高,运输途中遇闷热遭雨淋等情况发生,造成冷藏浸酸蚕种孵化率下降.笔者通过近几年的冷藏浸酸实际工作实践,认为要提高冷藏浸酸蚕种的孵化率,在冷藏浸酸工作中要注意加强以下几方面的工作.     

提高滞育卵冷藏浸酸孵化率技术的探讨

本文通过总结近几年国内外同行及本单位对滞育卵人工孵化的研究试验和实践,探索出提高滞育卵冷藏浸酸孵化率的部分技术要领,认为二化性品种滞育卵进入滞育时间在20日以内,采取浸酸-冷藏-浸酸形式,如冷藏时间在40天以上,配合补催青黑暗处理,其孵化率基本可达到生产上的要求,且对蚕体体质无不良影响,如冷藏时间在50天以上可在生产上放心使用.     

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。     

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。     

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。     

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.