近年来国内外提高奶牛产奶量的方法

近年来．饲养奶牛已成为各地农户增收致富的好项目。笔者在与本地饲养奶牛专业户座谈时了解到．部分饲养专业户所饲养的德系荷斯坦奶牛产奶量不高．其主要原因是缺乏科学的饲养管理知识．致使部分奶牛的生产性能还未发挥出来。针对生产中现存问题，笔者将近年来国内外一些提高奶牛产奶量的方法与经验，向养牛专业户介绍如下：     

提高奶牛产奶量的技术要点

饲养奶牛的经济效益．主要来源于成年母牛的产奶量。奶牛产奶水平的高低主要取决于遗传和环境两个因素，其中遗传因素占30％。环境因素占70％。在环境因素中。饲养管理是影响奶牛生产性能最重要的因素．特别是饲养水平和饲料影响最大。因此，不断改进和提高饲养技术，以充分发挥母牛的产奶潜力，获得较高的产奶量．是提高饲养奶牛经济效益最有效的途径。饲养中应主要注意以下几点：     

如何加强冬季奶牛的饲养

冬季寒冷而漫长，又是枯草季节。奶牛的采食量、产奶量和体重都有下降。奶牛如何越冬，便成为一个突出问题。奶牛最适宜的温度为8～16℃，冬季气温在0℃以下，如饲养管理不善，奶牛的产奶量就会降低。本文首先分析了冬季奶牛饲养中应注意的一些问题，同时针对这些问题提出了相应的饲养措施。     

金华市奶牛饲养及牧草种植现状的调查研究

金华地处浙江中西部,具备发展奶牛乳品业的有利条件,素有“江南奶牛之乡”之美誉。金华市饲养的奶牛绝大多数系荷斯坦奶牛,但由于种种原因,其年头平均产奶量长期徘徊在5000kg左右。在2003年9—12月期间随机抽查了丁丁、佳乐、白龙桥、雅畈等奶牛养殖场的饲养现状及牧草种植情况     

产犊季节和胎次对奶牛产奶量的影响

在奶牛饲养管理工作中，必须考虑影响产奶量的主要环境因素。研究资料表明，在奶牛生产中，产犊季节和胎次对产奶量影响较大。为了探讨产犊季节和胎次对奶牛产奶量爵移碱聍盛成市兴旺奶牛场559头奶牛，产犊季节和胎次对产奶量的影响进行统计分析，并做了对比试验。结果表明：奶牛在武威地区秋季产犊产奶量最高，冬季次之，夏季和春季最低。奶牛产犊季节、胎次与产奶量均无显著性关系（P〉0．05）。     

提高饲养户奶牛产奶量的综合技术措施

据统计．目前全国奶牛存栏约700多万头，其中个体奶牛饲养户饲养的奶牛头数占80％以上．因此，奶牛饲养户的生产水平对我国鲜奶产量和质量是非常重要的。饲养奶牛的目的就是多出奶、出好奶，多获利，但是，奶牛饲养户的实际情况并非如此，存在产奶量低、产奶期短，疾病不断发生等情况，严重影响奶牛饲养户的经济效益。下面结合奶牛产奶量的影响因素和提高产奶量的综合技术措施做一简单论述，供广大奶牛饲养户参考。     

奶牛围产期的饲养管理新理念

奶牛产奶量的高低，除受奶牛产奶遗传性能的影响外，而饲养管理是决定的因素，特别是围产期奶牛饲养的好坏，直接关系着整个泌乳期产奶高低，繁殖性能，奶牛和犊牛的健康。但在实际奶牛生产中对围产期的饲养管理往往被疏忽．在此仅就自己在实际工作中的体会简要叙述如下．仅供参考。     

农村中小型及家庭奶牛养殖场该怎样管理

近年来，随着城乡人民生活水平不断提高．人们对鲜奶的需求量不断增加，这为部分农村利用自身优势发展以家庭养牛为主的中小型奶牛场创造了良好条件，但由于许多奶牛饲养户饲养管理水平低，致使奶牛产奶量低、经济效益差。笔者经过多次深入农户进行调查探索．认为以下几项是当前农村奶牛养殖中提高饲养管理水平和产奶量所要采取的主要措施．     

浅谈冬季奶牛的饲养管理要点

近年来，有些专业户饲养的奶牛，一进入冬季后，其饲养的奶牛产奶量则出现产奶量下降的非正常现象，致使饲养奶牛的经济效益受到一定程度的影响。笔针对这一问题，并结合生产实践中的一些较好的做法与经验，现将冬季奶牛的饲养管理要点浅谈如下，供参考。     

奶牛要养好 运动不可少

农民单家独户分散饲养的奶牛由于不具备运动场，多为“禁闭式”养牛模式，给奶牛的健康状况、产奶量及使用年限带来不良影响。据调查，“开放式”饲养的奶牛平均每头每年产奶量为7吨．“禁闭式”饲养的奶牛产奶最则为5—6吨。常年“禁闭式”饲养舍饲的奶牛，冬春大都不发情或少发情．繁殖力明显降低，且利用年限缩短，发病率上升．腕前黏液囊炎、真胃移位（胃下垂）、难产、暑热喘气（热应激综合征）、乳房炎等病高发。所以，“奶牛要养好．运动不可少”。因此。农户在饲养奶牛时．牛舍和运动场要同时并重，饲养与运动并重．切不可偏废。     

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.