青贮饲料的利用技术

青贮饲料是指在密闭青贮设施(窖、壕、塔、袋等)中,或经乳酸菌发酵、或采用化学制剂调制、或降低水分而保存的青绿多汁饲料。它是调制和贮存青绿饲料,提高饲料利用率的一种有效方法,是饲养反刍动物(牛、羊等)不可缺少的基础饲料。     

牛瘤胃积食的综合防治

牛瘤胃积食又称急性瘤胃扩张,是反刍动物贪食大量的粗纤维或容易膨胀的饲料引起瘤胃扩张、容积增大,内容物蠕动停滞或阻塞,以及整个前胃机能障碍,形成脱水和毒血症的一种疾病.防止牛瘤胃积食的发生,除加强对牛的饲养管护,牛舍及周边环境保持清洁卫生外,还要注意牛体内缺乏Ca、Cu等矿物元素,形成异食癖,或误食塑料等难以消化的物质而引发该病.     

浅谈饲料加工质量的评价指标及控制技术

<正>我国的饲料产品包括单一饲料、饲料添加剂预混合饲料、浓缩饲料、配合饲料和精料补充料。除单一饲料以外,其他都是将多种饲料原料,按照规定的加工工艺,制成均匀一致的饲料产品。不同饲料产品的加工工艺不同,对加工质量的要求也不同,评价其加工质量的指标也不同。控制好饲料产品加工质量,是保证饲料产品质量的关键,有利于提高饲料的利用效率,降低生产成本,生产高品质饲料。1.饲料加工质量评价指标(1)粉碎粒度粉碎是所有饲料产品加工中的必     

"NPN"补充料对泌乳牛产奶性能的影响

目前作为蛋白质补充料的植物性和动物性蛋白资源短缺,价格昂贵,蛋白质饲料紧缺问题将成为制约畜牧业未来发展的瓶颈.开发利用非常规饲料资源将成为解决蛋白质饲料紧缺,提高畜产经济效益的一个有效途径和发展方向.反刍动物的瘤胃具有利用非蛋白氮的功能,而非蛋白氮的来源广泛、价格低廉,合理利用非蛋白氮对解决蛋白质原料紧缺,提高产业的经济效益具有重要意义.     

组织中全基因组DNA甲基化的液相色谱-串联质谱分析

建立液相色谱-串联质谱测定组织中全基因组DNA甲基化水平的方法。采用苯酚氯仿提取组织DNA,提取的DNA用88%甲酸在140℃下裂解,DNA裂解液加入同位素胞嘧啶作内标,经N2吹干后,用甲醇溶解,以液相色谱-串联质谱检测胞嘧啶和5-甲基胞嘧啶的含量,并计算全基因组中DNA甲基化的水平。结果表明,胞嘧啶的线性范围为1~100μg.L-1,相关系数为0.997 4,相对标准偏差为0.70%~4.09%;5-甲基胞嘧啶的线性范围为1~50μg.L-1,相关系数为0.994 8,相对标准偏差为0.60%~4.81%。胞嘧啶和5-甲基胞嘧啶的检出限为1 pg,日内相对标准偏差为1.86%~4.67%,日间相对标准偏差为3.72%~4.68%,胞嘧啶和5-甲基胞嘧啶的加样回收率为86.52%~105.14%。本研究所建立的方法检测组织中DNA甲基化程度,具有专一性强、操作简便的优点,能较好的满足全基因组DNA甲基化检测的要求。     

牛瘤胃积食概述及预防措施

牛瘤胃积食,是反刍动物贪食大量的粗纤维或容易膨胀的饲料引起瘤胃扩张,瘤胃容积增大,内容物停滞或阻塞,整个前胃机能障碍,形成脱水和毒血症的一种疾病。1.病因(1)原发性瘤胃食滞主要因过食草料,饮水不足,缺乏运动或饲料突然变更而致。(2)继发性瘤胃食滞在前胃弛缓、瓣胃阻塞、创伤性网胃炎、皱胃变     

大力推广草食动物营养舔砖技术

近年来,随着畜牧业规模健康养殖工程的实施和振兴畜牧战略的快速推进,山西省牛羊集约化养殖迅速发展,在全省各地逐渐形成了以养殖小区、园区为主要形式的现代草食畜牧业.但由于饲养管理粗放,饲料单一,一般以干草、农作物秸秆、青贮饲料为主,即使补充少量的精料,蛋白质和矿物质元素等营养物质摄取量也明显不足,营养失调问题普遍存在,严重影响草食动物的生长发育,降低了经济效益.草食动物营养舔砖是补充矿物质元素、非蛋白氮、可溶性糖等养分简单而有效的一种理想产品.草食动物通过对舔砖长期而缓慢的舔食,可获得常规饲料中容易缺乏的营养成分,满足机体生长发育需要,平衡饲料日粮养分,提高草食动物饲料利用率和生产的经济效益.     

动物尿素中毒的防治措施

尿素是一种非蛋白含氮化合物,含氮46.6%,被广泛的应用于畜牧业,它可代替反刍动物日粮中的部分蛋白质饲料,解决了畜牧业发展中蛋白质饲料的匮乏问题。但是不科学的饲喂方法,会引起动物中毒。     

安捷伦推出分析基因调控的芯片平台

安捷伦科技公司于9月12号推出了它的用于分析基因组调控区域活动的CHIP—on—chip芯片平台。真核生物的基因组DNA以染色质的形式存在，因此，研究蛋白质与DNA在染色质环境下的相互作用是阐明真核生物基因表达机制的基本途径。染色质免疫沉淀技术（chromatin immunoprecipitation assay，CHIP）是目前唯一研究体内DNA与蛋白质相互作用的方法。     

荠菜总基因组DNA提取方法的研究

采用改良CTAB法、CTAB法、SDS法和高盐低p H法分别对荠菜叶片进行基因组DNA的提取,比较4种方法提取DNA的浓度、纯度和完整性。结果表明,改良CTAB法获得的DNA浓度最高,为3105.85μg/ml,并且纯度高、完整性好、过程简单,确定荠菜基因组DNA的最佳提取方法为改良CTAB法。     

Molecular cloning and characterization of a novel mannose-binding lectin cDNA from Zantedeschia aethiopica.

Using RNA extracted from Zantedeschia aethiopica young leaves and primers designed according to the conservative regions of Araceae lectins, the full-length cDNA of Z. aethiopica agglutinin (ZAA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zaa was 871 bp and contained a 417 bp open reading frame (ORF) encoding a lectin precursor of 138 amino acids. Through comparative analysis of zaa gene and its deduced amino acid sequence with those of other Araceae species, it was found that zaa encoded a precursor lectin with signal peptide. Secondary and three-dimensional structure analyses showed that ZAA had many common characters of mannose-binding lectin superfamily and ZAA was a mannose-binding lectin with three mannose-binding sites. Southern blot analysis of the genomic DNA revealed that zaa belonged to a multi-copy gene family.     

Modifications in chromatin morphology and organization during sheep oogenesis

This research has been designed to study the major events of nuclear remodeling that characterize sheep oocytes during the early stage of folliculogenesis (transition from preantral to antral stage). In particular, the modifications in large-scale chromatin configuration, the global DNA methylation, and the process of telomere elongation have been investigated as crucial events of oocyte nuclear maturity. In addition, the spatio-temporal distribution of the major enzymes involved in DNA methylation, the DNA methyltransferase 1 (Dnmt1), and in telomere elongation, telomerase catalytic subunit (TERT), have been described. To these aims, the nuclei of isolated oocytes were investigated using immunocytochemistry and Q-FISH analyses. In absence of preliminary information, these nuclear determinants were compared with those of fully competent germ cells obtained from medium and preovulatory antral follicles. The nuclei of sheep oocytes acquired a condensed chromatin configuration, stable high levels of global DNA methylation, and a definitive telomere length already in the majority of late growing stage oocytes (110 microm) derived from early antral follicles. In addition, while the process of methylation resulted strictly related to oocyte diameter, the telomeric program appeared to be highly chromatin configuration-dependent. The translocation of Dnmt1 and TERT from the nucleus to the cytoplasm in the oocytes derived from early antral follicles seems to confirm the definitive chromatin asset of these germ cells. In conclusion, changes in large-scale chromatin structure, epigenesis, and telomere size in the sheep are established prior to oocyte acquires the ability to resume meiosis.     

基于虚拟仪器的光电探测设备实验系统设计

为了实现光电探测各项实验功能,在某型光电探测设备实验系统中采用工业级光电传感器对目标进行成像探测和测距,采用双轴转台控制光轴的转动,通过工控机控制系统工作。实验系统软件采用LabVIEW2009设计,通过图像采集处理子程序对传感器图像进行采集和处理,可实时显示探测的图像并叠加上工作状态信息;通过转台控制子程序可灵活的控制光轴的指向;采用通信控制子程序可方便地控制传感器工作和进行数据传输。     

Construction of engineered murine embryonic stem cells with conditional knockout of FGFR2 depending on Cre-loxP.

OBJECTIVE: To investigate the functions of Fibroblast Growth Factor Receptor-2 (FGFR2) at different stages of cell differentiation. The engineered murine embryonic stem (ES) cells with conditional knockout of FGFR2 were developed depending on Cre-loxP. METHODS: Cre-loxP system was used in a conditional targeting vector. The competent AM-1 bacteria, which expressed Cre-recombinase, was used to confirm the Cre-mediated deletion of the floxed exons 7 and 8 of FGFR2. The targeting vector was electroporated into the ES cells, and the transfected ES cells were screened with G418 and Ganciclovir. Finally, the ES clones with correct targeting events were identified by Southern Blot and PCR. RESULTS: The targeting vector with conditional knockout of murine FGFR2 was successfully constructed and confirmed by PCR and digestion analysis in bacteria. 86 ES clones were collected by selective culture with G418 and Ganciclovir. Four of the 86 ES clones were found containing the targeting gene sequence in genomic DNA proved by Southern Blot with a 5'-end flank probe. Two of the four ES clones had the correct targeting events that included the insertion of the targeting gene sequence in genomic DNA and were checked by Southern Blot with a 3'-end flanking probe. Finally, the insertion of loxP (loxP3) between exons 8 and 9 in genomic DNA was identified in one of the two ES clones by Southern Blot and PCR. CONCLUSION: FGFR2 conditional knockout depending on Cre-loxP can be successfully used in ES cells.     

基于甲基化DNA分离方法的甲基化DNA检测和全基因水平的甲基化分析

已知异常的DNA甲基化对基因表达有明显影响并且涉及包括癌症等的疾病以及正常状态,因此从非甲基化DNA中鉴定甲基化DNA的分析技术是非常必须的。本文介绍了一种利用甲基化DNA结合域对甲基化DNA的亲和性质将甲基化DNA从全基因中成功提取的甲基化DNA分离技术（MeDIA）。结合MeDIA的PCR和CpG芯片技术分别实现了局部位置甲基化DNA状态的评估以及全基因的甲基化分析。     

基于电泳分离的生物芯片的设计与改进

在一种低压驱动电泳分离的阵列电极模块基础上，设计制作了一款电泳分离用的基于1VIEMS技术的微流体沟道芯片，与电极模块及控制检测系统共同组成微全生物芯片系统。通过控制系统进行了一系列电泳实验，根据实验结果确定了沟道芯片的最佳尺寸参数。对阵列电极模块进行了改进，在上面增加了一对检测电极，通过比较几种检测方法选择对电泳分离实验进行阻抗检测，以实现检测系统的微型化。通过基于单片机的检测系统对电泳实验分离结果进行一系列的阻抗检测实验，实验结果证明检测电极的设计是可行的。     

基于MSP430单片机的便携式电化学DNA检测系统

为实现现场DNA杂交检测,设计了一套便携式电化学DNA检测系统;系统以MSP430单片机为主控芯片,结合外围恒电位电路和控制软件,实现电化学循环伏安法检测;电化学DNA生物传感器利用原位电化学共聚合技术将DNA探针包埋固定在导电聚吡咯分子网络中,利用DNA杂交反应改变聚吡咯氧化还原过程中的离子交换动力学行为的原理实现DNA杂交检测;设计的DNA检测系统硬件结构检测,低功耗,精确实现电化学循环伏安法检测;配合电化学DNA生物传感器,可实现无标记DNA检测,检测下限达到5×10-18M,适合在野和个性化DNA检测。     

FOULING DETECTION IN FOOD VESSELS USING INTERDIGITAL LAMB WAVE TRANSDUCER

Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative distribution of the in-plane and out-of-plane displacement of the mode across the thickness of the plate will determine the sensitivity of the mode to a particular loading condition. By considering the dispersion and multi-mode characteristics of guided waves, an interdigital polyvinylidene fluoride (PVDF) transducer is designed to realize the mode selection of guided waves, and a single a0 mode is used for guided wave detection. Fouling detection experiments are conducted in the laboratory using epoxy adhesive on a thin plate. Using the interdigital PVDF transducer, three fouled areas are detected. Using one of the time-frequency analysis methods, the waveforms are further processed. This also demonstrates the validity of this method of fouling detection.     

MassworksTM结合NIST11谱库在羊油香气成分准确定性分析中的应用

应用Massworks^TM质谱解析软件结合NIST11谱库,定性分析羊油的香气成分。在Massworks^TM质谱解析软件中,以全氟三丁胺质谱图为标准建立质谱校正函数,对热脱附-气相色谱-质谱联用法（TD-GC/MS）采集的羊油香气原始扫描谱图进行质量轴和峰形校正,通过低分辨质谱获得各化合物的精确质量数,并利用同位素峰形校正技术（CLIPs Search）进行检索,获取未知目标化合物的分子式,同时与NIST11谱库的检索结果比对。结果表明,通过Massworks^TM与NIST11谱库结合实现了快速、准确定性分析羊油香气成分,最终确定42种香气成分。利用Masswork^TM软件的参数优化,解决了NIST11谱库中检索匹配度低、存在共流出化合物以及目标化合物无分子离子峰等问题,获取了化合物离子碎片信息并进行了解析。该定性方法可为未知天然产物香气成分的分析提供方法参考。