在人工饲料育中五龄期的食下量、消化量和蚕体重的关系

调查原蚕人工饲育育五龄期逐日食下量及逐日消化量与蚕体重的相互关系.以其开始食下时的蚕体重,除逐日食下量和逐日消化量的值(食下指数和消化指数),是随着五龄经过几乎呈直线低下.这个倾向不管饲育密度,给桑量、饲育温度及饲料组成,虽有某程度的变动,也不管蚕体重有多少差异,甚至雌雄均可认出.无论在食下指数或消化指数与五龄经过之间,均能得到相关系数较高的回归直线式.即将五龄期食下量及消化量的变迁以单位体重来看,则初期最高,其后随成长而直线低下.并且由于依蚕体重为指标,于其后的食下量,就能进而知道适当正确的给饵量等,在实用上也是有效的.     

蚕品种两广二号雌雄个体饲料转化率差异性试验

本试验以广西年饲养量最多的家蚕品种两广二号为研究对象,调查其雌雄个体间饲料转化效率。结果表明：两广二号雄蚕个体平均食桑量4龄期为雌蚕的92．26％、5龄期约为雌蚕的94．02％,整个大蚕期雄蚕个体的平均食桑量为雌蚕的93．80％;50kg桑叶产全茧量雄蚕为5．57kg,是雌蚕的87．01％,显著低于雌蚕;50kg桑叶产茧层量雄蚕比雌蚕的高6．78％,说明两广二号品种的雄蚕叶丝转化率略高于雌蚕,但差异不显著。     

秋蚕五龄给桑量、饲育面积、日给桑次数优化组合研究

本试验利用正交试验法，以50kg桑产茧、产茧量、全茧量、茧层率、食下率为指标，对五龄家蚕给桑量、饲育面积、日给桑次数三因素的组合进行了优化选择，得出200头秋蚕五龄期的给桑量2520g、饲育面积0.14m^2、日给桑次数2次的组合较佳。     

关于提高叶丝转化率的研究——Ⅰ.影响产茧量及叶丝转化率的几种因素

<正> 一、前言 蚕以桑叶为食料,从中摄取各种营养物质,借以建造蚕体,维持生命和生产丝物质。一条蚕从蚁蚕到上簇约食下桑叶20～25克,其中85％以上是在第5龄食下的,蚕体内丝腺的极度成长和丝物质的大量合成,也是在5龄期。现行蚕品种在5龄期大致食下桑叶9     

提高蚕叶丝转化率研究综述

叶丝转化率是蚕生理性状的综合表现,也是养蚕生产上重要的经济指标.蚕从桑叶摄取各种营养,用来建造蚕体,维持生命和生产丝物质.1条蚕从孵化到上族约食下鲜叶20～25g(干物4.7g左右),其中85%以上在第5龄食下,蚕体丝腺的极度长大和丝物质的大量生成,也在5龄期.现行蚕品种在5龄期大致每食下鲜叶10kg,产茧1.1kg、产丝0.20～0.26kg,叶茧转化率约为11%,叶丝转化率约在2.0～2.6%.即在不同条件下,蚕食下同样量的桑叶,消化吸收转化成丝的     

家蚕新品种浙凤1号晚秋试养评价

浙凤1号是浙江省农业科学院蚕桑研究所利用雌蚕无性克隆系与限性卵色系杂交育成的单交品种.经小区和大区试验对比,该品种龄期较对照区长12 h;食桑性较好,蚕体略大,500 g熟蚕较对对照区减少9条;张种产茧量较对照区增加3.0 kg以上;解舒丝长、清洁、净度等丝质指标高于对照.该品种在农村饲养表现优良,可以推广.     

五龄蚕饲养技术探讨

桑蚕五龄期是丝腺生长最快的阶段,丝腺重约增长40倍;同时又是食桑最旺的时期,食下量约占全龄食下量的88％以上。此时的营养及气象条件,均间接或直接的影响蚕的体质、蚕龄经过、丝蛋白的合成等     

春秋兼用蚕品种川蚕23号农村比较试验

对四川省农业科学院蚕业研究所育成的春秋兼用蚕品种川蚕23号进行了春秋季实验室和农村比较试验,实验室试养表明:川蚕23号属中等茧型,中丝量蚕品种,龄期经过短,健康好养。与对照品种871×872相比,5龄经过短27h,万头蚕产茧量、万头蚕茧层量分别低1.04%、2.91%,100kg桑产茧量提高8.58%;与夏芳×秋白比较,川蚕23号万头蚕产茧量、万头蚕茧层量、100kg桑产茧量分别提高4.31%、3.62%、3.70%;与洞庭×碧波比较,川蚕23号万头蚕产茧量、100kg桑产茧量分别提高1.27%、2.85%。农村试养表明:该蚕品种耐粗食能力强,食桑快、用桑少、上蔟涌、营茧快,特别为养蚕大户所欢迎,是1对适于全年多次省力化养蚕的优良蚕品种。     

谈谈对大蚕饲养中几个问题的看法

习惯上称蚕的四、五龄期为大蚕期。大蚕期食桑量大,绢丝腺发达,呼吸量大,对高温多湿的抵抗力弱。因此,在饲养大蚕时要根据这些生理特点,改善其饲育环境,促使其充分饱食,达到蚕大茧重丝多的目的。现就大蚕饲养中的一些问题谈谈本人的看法。一、合理用叶大蚕期的饱食是增产蚕茧和丝量的关键。但大蚕期的食桑量大,约占整个龄期的95%以上,尤其是第五龄约占全龄的85%左右。因此在饲养大蚕中,要注意既要促使蚕儿饱食,又要节约用桑,做到合理用桑。我们曾对五龄期蚕儿食桑时间进行调查,在24小时内,16～20小时有叶与24小时     

家蚕不同发育阶段对微粒子孢子的感染性研究

从蚁叠至5龄末期不同发育阶段,经口食下一定量的微粒子孢子,均可使蚕感染发病,发病率的高低与食下微粒子孢子数量呈正相关。同一龄期,起蚕比食桑24小时后的蚕对微粒子孢子的感染发病率高。蚕在1龄期食下大量的微粒子孢子,则全部在幼虫期发病死亡,无结茧个体;食下量较少可结茧化蛾,但蛾的微粒子孢子检出率可高达71.43~100%。4龄后期至5龄末期(5龄6足天)食下微粒子孢子虽在幼虫期内不发病死亡,能结茧,但在死蛹和蛾中微粒子孢子检出率均较高。     

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.