配种到户几种保定方法

随着科学技术的不断创新,通讯事业飞速发展,千家万户都安上了电话,家畜繁育改良工作也由过去在繁育中心坐家配种转变为主动到农户家中服务,母畜保定就成了当前比较棘手的问题.为了解决母畜保定问题,我们采用了以下几种方法仅供参考.     

黑龙江省养蜂史概况(二)

二十世纪前半期一、意大利蜂的引入1903￣1920年,西方蜂种(主要是意蜂)及新养蜂法先传入福建、广东、香港、天津、北京等地,不久也传入黑龙江省。民国初年的养蜂情况《珠河县志》有以下记载:"民国初年,西洋蜂种及养蜂法传来以后,     

母猪产后不食的分型疗法

(一)病因类型 1.消化不良型:母猪产前精料喂的过多,或突然更换饲料,加重胃肠负担,引起消化不良.此病常发于分娩之后,体温正常,食欲不振,粪便先干后稀,有的病猪喜欢喝点成汤,有的吃点鲜块茎和生米等食物,但数量不大,严重者食欲废绝.     

国内玉米价格涨跌两难

随着年关临近，为了确保产区农民收入稳定增长，近日，政府有关部门出台了东北储备粮收购计划。在该重大利好政策拉动之下，我国部分产区玉米价格有望触底反弹，但受市场供应依然充足、需求整体依旧偏弱影响，国内玉米市场行情涨跌两难，具体分析如下：     

浅谈貉的饲养管理

1 配种准备期的管理 1.1营养供给原则 要维持本身的需要,使其肥胖度适中,外形匀称.另外,补充由于繁殖而消耗的营养物质,供给冬毛生长所需的营养物质.建议日粮标准是:10～11月份,鱼肉类10%～15%,动物副产品5%～10%,谷物70%,蔬菜10%.食盐2.5%,骨粉5%～10%,12月到明年1月份,鱼肉类20%～25%,动物副产品5%～10%,谷物'70%,蔬菜10%,酵母5%～8%,食盐2.5%,骨粉5%～10%,维生素A、B适量.给饲标准:10～11月份每只每日550～700g;12月份到明年1月份每只每日400～500g.     

主要组培花卉品种介绍

非洲菊:又名扶朗花,菊科,大丁草属,多年生草本植物;原产非洲南部,性喜温暖,阳光充足和空气流通的环境,不耐寒,忌炎热,生长适温20￣25℃,喜疏松、肥沃、排水良好且富含有机质的微酸性土壤。园艺品种花色丰富,有白、红、粉、黄等色系。兼有切花和盆花类型。彩色马蹄莲:天南星科多     

对河南桑蚕“十一·五”发展规划的几点建议

<正>河南省地处黄河中下游，蚕业生产历史悠久。建国50年以来，尤其是近20g间，经过“七·五”至“八·五”的迅速发展和“九·五”、“十·五”的稳步调整，河南蚕业生产规模基本稳定，生产水平得到提高。目前全省桑园面积1．67万hm~2，年产桑蚕茧6000t，与建国时相比，桑园面积和蚕茧产量分别增长了24倍和42．2倍，与改革开放初期的1978年相比，分别增长了2．25倍和4．18倍；蚕业深加工等综合产值达到10亿元，农民收入达5亿元，出口创汇8600多万美元。“九·五”、“十·五”期间，河南茧丝绸业保持着北方诸省(山东、陕西省除外)生产、出口主要基地和传统优势产业、出口创汇大户的地位。蚕业生产已成为不少平原和山区农民脱贫致富奔小康的支柱产业。 1 “九·五”、“十·五”实际生产情况 1．1 实际生产情况 1．1．1 生产规模保持基本稳定桑蚕生产在经历了1995年“全面下滑”桑园规模大幅度缩减后，“九·五”期间，全省蚕茧的总产和年产量也相应减少，但集中产     

缩小分组饲养的面积

在丹麦,人们已经提出一个分组饲养妊娠母猪的新观念,名叫"最佳猪栏",它把群饲设备与单独饲喂和铺有稻草、排水良好的地面结合在一起,见图1.对这种设计的研究显示,给妊娠母猪建成一个既有饲喂/休息的去处,又有一个铺垫良好的躺卧处的猪栏-所占面积总量与配备给群饲母猪的电子饲喂系统的场地所使用的面积相当.     

发现商机的14大法则

商机无论大小,从经济意义上讲一定是能由此产生利润的机会.商机表现为需求的产生与满足的方式上在时间、地点、成本、数量、对象上的不平衡状态.旧的商机消失后,新的商机又会出现.没有商机,就不会有"交易"活动.商机转化为财富,必定满足五个"合适":合适的产品或服务,合适的客户,合适的价格,合适的时间,合适的渠道.目前我们能认识的商机大致可归结为14种:     

夏秋季节怎样防治乌龟红甲病

夏秋季节龟活动较多,或运输中腹甲损伤,或池子粗糙引起磨损龟甲后而导致龟甲内局部红肿发炎,多数常见于腹甲内部有出血斑块,并向四周浸润扩散,严重时可波及整个龟甲,引起败血症而死亡.池中水质差、消毒少、水底氧气少时易产生大量单孢杆菌是引起此病的元凶.     

Knockout of targeted gene in porcine somatic cells using zinc‐finger nuclease

Targeted genome editing is a widely applicable approach for efficiently modifying any sequence of interest in animals. It is very difficult to generate knock‐out and knock‐in animals except for mice up to now. Very recently, a method of genome editing using zinc‐finger nucleases (ZFNs) has been developed to produce knockout rats. Since only injection of ZFNs into the pronuclear (PN) embryo is required, it seems to be useful for generating gene‐targeted animals, including domestic species. However, no one has reported the successful production of knockout pigs by direct injection of ZFNs into PN embryos. We examined whether ZFN works on editing the genome of porcine growth hormone receptor in two kinds of cell lines (ST and PT‐K75) derived from the pig as a preliminary study. Our data showed that pZFN1/2 vectors were efficiently transfected into both ST and PT‐K75 cells. In both cell lines, results from Cel‐I assay showed that modification of the targeted gene was confirmed. We injected ZFN1/2 mRNAs into the nucleus of PN stage embryos and then they were transferred to the recipients. However, pups were not delivered. Taken together, ZFN can be an available technology of genome editing even in the pig but further improvement will be required for generating genome‐modified pigs.     

Cell Biology Symposium: Zinc finger nucleases to create custom-designed modifications in the swine (Sus scrofa) genome

Engineered zinc finger nucleases (ZFN) are rapidly gaining popularity as a means to enhance the rate and specificity of DNA modifications in plant and animal cells. Repair-mediated gene modification by ZFN is driven by introducing DNA double-strand breaks via a nonspecific nuclease domain linked to a sequence-specific zinc finger nucleotide recognition domain. This review examines the use of ZFN to produce genetically modified swine and the potential of this technology for the future. By combining conventional gene targeting methods with somatic cell nuclear transfer, several genetically modified pig models have been produced. These conventional techniques are inefficient in mammalian somatic cells and provide little control over the site specificity and rate of exogenous DNA integration. The use of engineered ZFN that bind and cleave genomic DNA at specific loci can enhance targeting efficiencies by orders of magnitude. Recent publication of the first genetic modification in pigs by combining ZFN technology with somatic cell nuclear transfer has opened the door to genome targeting with a precision that was not previously possible in a large animal model. Since that time, model pigs with selective knockout of endogenous genes have been produced. This review will examine the use of ZFN to generate these pig models and the potential of ZFN to accelerate the production of genetically modified pigs of agricultural and biomedical importance. Current methods of ZFN design, important considerations for their safe and effective use in modification of the swine genome, and future innovative applications of this technology in pigs will be discussed.     

CRISPR/Cas9基因编辑技术及其在肉牛基因组编辑中的应用

自DNA双螺旋结构发现以来,人们在基因的编辑和改造方面取得了长足步,CRISPR/Cas9技术的出现为基因编辑提供了一个新方法。CRISPR/Cas9系统是由 CRISPR基因座与Cas9蛋白组成的基因编辑系统,相比于传统的ZFNs技术和TALENs技术,具有便捷、高效、应用范围广、精确的优点。肉牛作为重要的畜牧经济动物,CRISPR/Cas9技术也被运用于其品种改良,涉及的方面有抗病抗逆、改善肉质、提高出肉率等。本文将阐述近年来CRISPR/Cas9技术在肉牛上的应用,为后期相关研究提供参考。     

Development of genome engineering technologies in cattle: from random to specific

The production of transgenic farm animals(e.g., cattle) via genome engineering for the gain or loss of gene functions is an important undertaking. In the initial stages of genome engineering, DNA micro-injection into one-cell stage embryos(zygotes) followed by embryo transfer into a recipient was performed because of the ease of the procedure.However, as this approach resulted in severe mosaicism and has a low efficiency, it is not typically employed in the cattle as priority, unlike in mice. To overcome the above issue with micro-injection in cattle, somatic cell nuclear transfer(SCNT) was introduced and successfully used to produce cloned livestock. The application of SCNT for the production of transgenic livestock represents a significant advancement, but its development speed is relatively slow because of abnormal reprogramming and low gene targeting efficiency. Recent genome editing technologies(e.g.,ZFN, TALEN, and CRISPR-Cas9) have been rapidly adapted for applications in cattle and great results have been achieved in several fields such as disease models and bioreactors. In the future, genome engineering technologies wil accelerate our understanding of genetic traits in bovine and wil be readily adapted for bio-medical applications in cattle.     

Finding of a highly efficient ZFN pair for Aqpep gene functioning in murine zygotes

The generation efficiencies of mutation-induced mice when using engineered zinc-finger nucleases (ZFNs) have been generally 10 to 20% of obtained pups in previous studies. The discovery of high-affinity DNA-binding modules can contribute to the generation of various kinds of novel artificial chromatin-targeting tools, such as zinc-finger acetyltransferases, zinc-finger histone kinases and so on, as well as improvement of reported zinc-finger recombinases and zinc-finger methyltransferases. Here, we report a novel ZFN pair that has a highly efficient mutation-induction ability in murine zygotes. The ZFN pair induced mutations in all obtained mice in the target locus, exon 17 of aminopeptidase Q gene, and almost all of the pups had biallelic mutations. This high efficiency was also shown in the plasmid DNA transfected in a cultured human cell line. The induced mutations were inherited normally in the next generation. The zinc-finger modules of this ZFN pair are expected to contribute to the development of novel ZF-attached chromatin-targeting tools.     

牛肌肉生长抑制素基因打靶载体的构建与鉴定

本试验旨在构建用于牛肌肉生长抑制素(MSTN)基因敲除的置换型打靶载体。基于已发布的MSTN基因序列,选取第3外显子约600 bp作为靶位点,在其上、下游设计2条同源臂,分别为4.4和1.4 kb。以pPNTⅢ为骨架载体,在其2个多克隆位点处插入同源臂,构建出置换型打靶载体MSTN-KO-pPNTⅢ。结果显示,经DNA测序及酶切鉴定证实1.4 kb同源短臂和4.4 kb同源长臂均正确插入基础载体中。结果表明,成功构建出牛MSTN-KO-pPNTⅢ打靶载体。     

Molecular investigation of zoonotic intracellular bacteria in Chilean bats

Intracellular pathogens were investigated for the first time in 55 Chilean bats belonging to six species. Using a conventional PCR protocol targeting a fragment of the ITS region, 21 bats (38 %) were positive for DNA of Bartonella sp. Molecular characterization of fragments of the gltA, rpoB and fstZ genes and subsequent phylogenetic analysis indicated the presence of diverse genotypes related to Bartonella from bats worldwide. DNA from C. burnetii was investigated using a real-time PCR (qPCR) protocol targeting the IS1111 gene and yielded positive results for 5 individuals (9%), being the first report of C. burnetii in wildlife in Chile. All bats were negative for Rickettsia sp., evaluated by qPCR for the gltA gene, confirming that bats do not act as important reservoirs for Rickettsia. This preliminary survey calls for more comprehensive studies on the epidemiology of these agents, including larger sample sizes, the evaluation of potential transmission routes and spillover potential.     

植物抗旱基因工程研究进展

干旱是影响农作物产量的主要胁迫因素之一。高通量生物技术的使用促成了新的干旱胁迫相关基因的发现,一些重要基因已转化到植物中,通过专一性或广谱性地应答路径来调节其干旱耐受性。最近的一些研究进展,进一步加深了对植物通过调控干旱相关基因的表达而抵御干旱胁迫的理解,并对植物干旱胁迫的复杂调控网络有了更深刻的认识,同时逐渐探索出一些具体的植物抗旱基因工程研究的途径。本文主要综述了信号分子、转录因子、小RNA分子、渗透调节分子、多胺类分子,活性氧清除分子方面的基因工程研究进展,并对其研究中存在的问题及应用前景进行了讨论。     

Chi基因的克隆及转基因马铃薯植株的获得

为了提高马铃薯对真菌病害的抗性,本试验进行了马铃薯转基因抗病育种的初步研究。通过PCR扩增,从生防木霉菌Trichoderma atroviride的cDNA中克隆到一个内切几丁质酶基因Chi,构建了植物表达载体p33ECR-Chi。通过农杆菌介导的转化方法将Chi基因转化到马铃薯栽培品种“费乌瑞它”和“夏波蒂”试管薯片中。经侵染和共培养后,用卡那霉素和羟苄青霉素筛选抗性芽,共获得18株植株,对所得转化植株进行PCR检测,结果12株为阳性,占67%。本试验为利用基因工程技术提高马铃薯的生防能力奠定了基础。