BLUP中分子血缘相关矩阵A逆阵的直接计算法

自上个世纪８０年代以来，随着计算技术的发展，BLUP法在动物生产特别是奶牛和肉牛生产上得到广泛应用，使动物的改良效益大幅度提高。畜牧业发达国家，商用种畜的价值评定主要依据BLUP结论。我们知道，BLUP是建立在混合模型基础上的动物育种值的线性评定方法。为了计算模型中动物个体间遗传效应协方差，需要计算分子血缘相关矩阵的逆矩阵。从逆矩阵的常规运算思路出发，是先建立血缘相关矩阵再求它的逆矩阵。然而，当动物个体数量很大时，这种由矩阵而逆矩阵的计算，就目前的计算技术是不可能完成的。BLUP的创始人Henderson（１９７…     

单性状BLUP法应用于上海奶牛育种

<正> 由于电子计算机的普及,早在70年代初由美国Henderson教授创立的最佳线性无偏预测(BLUP)法在家畜育种界逐渐得到了推广应用。在80年代初,我国学者纷纷开展了对这一新技术的研究和应用。如我国学者北京农业大学的张沅、张勤以及贵州农学院的俞渭江等不仅全面研究了BLUP法在我国奶牛育种中的应用,还设计编制了BLUP计算程序。 另外,由于现代奶牛育种工作的发展,尤其对于     

介绍BLUP及一种计算育种值的方法

<正> 一、BLUP的含义及其使用方法BLUP是一种使育种值估计公式达到“最佳线性无偏予测”的方法,引号中的英文字首就是“BLUP”,即:Best——“最佳的”,意指估计育种值(I)和客观存在的真值(T)之间的误差是最小的。Linear——“线性的”,意指估计育种值I是记录值y~*的线性函数,旨在便于计算。Unbiased——“无偏差的”,意指要计算出环境影响(?),不让它造成估计偏差。Prediction——“予测”,意指估计育值(I)是对真值(T)的予测。     

用BLUP方法估计辽宁绒山羊种公羊育种值的研究

由于羊的最优线性无偏估计法(BLUP法)评定育种工作开展得较晚,特别在绒山羊的育种工作中应用更少.本研究试图利用辽宁绒山羊原种场的生产资料对BLUP法用于种公羊的育种值评估方面进行初步尝试,以推进BLUP法在绒山羊育种中的应用.     

微型计算机在家畜育种中的应用软件：—BLUP和VCCE软件简介

作者根据多年来在BLUP法方面的研究和奶畜育种实践,应用高级可编译的TRU BASIC语言,研制了一套实用于现代家畜育种的BLUP & VCCE软件包,该软件包括了目前BLUP和VCCE所涉及的所有模型,可以满足国内育种界同行应用BLUP法的要求。该软件可以在国内现有的所有微机上运行,包括IBM/PC、XT、AT、286、386等微机。     

继代选育中用BLUP法对公猪进行逆向再评定的研究

用带亲缘相关阵的BLUP法(BLUP-1),不带亲缘相关阵的BLUP法(BLUP- 2)及最小二乘法(LS),就日增重、背膘厚及外形评分三性状对SD-I系种公猪进行了逆向遗传再评定,以探讨BLUP法在猪继代选育中的应用。结果表明:①对遗传力较高的性状用综合指数法选择是比较理想的;②BLUP法较LS法精确,且以BLUP-1最精确,估计误差方差(PEV)最小;③选育中可用经加权而成的BLUP综合育种值代替多性状育种值。     

利用微电脑求解BLUP值举例

本文仅从实际应用角度考虑,将我们编制的求解BLUP值电算程序介绍给广大的奶牛工作者(该程序已通过LASER 310及PC—1500型微电脑运行)。为了从简起见,本文对有关BLUP的详细情况不作介绍,读者可参看《中国奶牛》1984年第1期俞渭江所著文章。应用该程序主要可以简单方便的求解出乳用种公牛的BLUP值,对于不懂得如何建立有唯一解的BLUP混合模型方程组的同志更是有益     

宁乡猪育种规划的方法

<正>BLUP法是数理统计在遗传学上的应用,基于线性代数和数理统计模型方法。对于BLUP法估计育种值模型可以分为公畜模型、公畜-母畜模型、外祖父模型、动物模型及简化动物模型,其中公畜模型未能对影响后代的母畜效应进行有效的计算,在同质选配过程中会对公畜效应的预测带来一定的偏差,同时也不能预测后代的个体效应;公畜-母畜模型也不能预测后代个体效应,而外祖父模型适用于种公牛评定,缺点也     

BLUP法应用于警犬联合育种的探讨

最佳线性无偏预测(BLUP,Best Linear Unbiased Prediction)是当前应用最广泛的家畜遗传评定方法。本文介绍了BLUP法的形成、优点以及在我国警犬联合育种中的应用和需要解决的问题。     

BLUP法在畜禽个体遗传评估中的应用与展望

最佳线性无偏预测（BLUP）是评定畜禽种用价值的一种先进方法，将选择指数法和最小二乘估计方法有机结合，解决了选择指数法存在的问题。自20世纪70年代以来，BLUP法已在奶牛、肉牛、猪、羊及家禽的遗传改良中得到了广泛应用。本文主要就BLUP法的研究进展及相关问题进行综述、讨论，供参考。     

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.