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要大力发展养羊业,繁殖技术是关键环节之一。要提高羊的繁殖力,必须依靠先进的繁殖技术,充分利用和发挥羊的繁殖力。现提出以下几项技术措施。
1 采用以繁殖性状为主的综合选种方法
在引种时要选择具有生长快、体型大、适应性强、出肉率高等特点的羊,如夏洛来羊、澳州美利奴羊、小尾寒羊、波尔山羊等。然后在其繁殖过程中,选留后备种羊时,要注意繁殖性状的选择,采用以繁殖性状为主的综合选种方法。选择繁殖性能强,遗传性能稳定,生产发育良好,生产性能高的公母羊作种羊留用。种公羊性欲旺盛、雄性强,睾丸发育正常,运动灵活;种母羊要母性好,泌乳力强。 相似文献
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小尾寒羊是我国众多绵羊地方良种中的佼佼者,以其体格大、繁殖力高、适宜舍饲等诸多优点而著称,被业内人士喻为现代化杂交肉羊生产的理想母本品种和绵羊家族中的世界级宝贵遗传资源。当前小尾寒羊引种饲养渐成热门。现仅就小尾寒羊引种及繁育中的品种鉴定技术要点简介如下,以供即将引种者及养羊户参考。1掌握品种特征辨别纯种1.1外貌特征一是体型较长且高大,体躯紧凑,四肢细高。公羊体躯丰满紧凑、四肢高而坚实,耆甲微微隆起,背腰平直,侧视呈长方形,成年公羊雄壮威武;母羊体躯瘦高、后躯发达,十字部略高,侧视为梯形。二是鼻梁隆起、耳大下垂… 相似文献
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4～6月龄羔羊是肌肉生长最快的时期,对羔羊进行快速育肥,即肥羔肉生产,是发展商品肉羊生产的极佳途径,现就羔羊全舍饲快速育肥术措施介绍如下: 1 选择杂交羔羊育肥 选择产肉性能较好的国外优良肉用品种公羊,如无角多塞特公羊、林肯公羊、德国美利奴公羊等与多胎高产的小尾寒羊母羊进行杂交,所产生的杂交羔羊进行育肥,能明显提高小尾寒羊的产肉性能. 相似文献
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在畜禽育种中,许多重要的经济性状,如肉质性状、繁殖性状、产奶性能、产蛋性能等多属数量性状,主要假说认为数量性状是由多效微基因共同影响、受遗传背景和环境协同作用。其中将数量性状所处的染色体区段中一个或多个基因座位,称为数量性状基因座位(QTL)。讨论QTL定位在畜禽育种中的使用。 相似文献
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Prospects for genetic technology in salmon breeding programmes 总被引：1，自引：0，他引：1
Selective breeding has been very successful in increasing production in Atlantic salmon. Gene technology opens new opportunities to comprehend the nature of the genetic variation underlying production traits. Two major areas in which gene technology may play an important role are (1) production of genetically modified fish and (2) development and utilization of genetic markers. Several studies of transgenic salmonids have shown substantially increased growth rates. However, many different issues are related to whether genetically modified fish should be used or not. Genetic markers can be used for aquaculture purposes and for monitoring wild populations. Construction of genetic maps based on markers enables the identification of quantitative trait loci (QTL) and/or markers linked to them. This will facilitate marker‐assisted selection, enabling improvement in economically important traits, in particular traits difficult to breed for, such as food conversion efficiency and disease resistance. Several experiments aimed at mapping QTL in salmonids using genetic markers are ongoing. DNA marker technologies can also be used for identification and monitoring of lines, families and individuals, and for genetic improvement through selection for favourable genes and gene combinations. 相似文献
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凉山半细毛羊微卫星标记多态性的研究 总被引：1，自引：0，他引：1
利用微卫星技术对凉山半细毛羊核心育种群206个个体第1、2、3、9号染色体上的18个微卫星位点进行研究,检测微卫星在凉山半细毛羊中的等位基因数,计算等位基因频率(Pi)、遗传杂合度(H)和多态信息含量(PIC),分析了凉山半细毛羊微卫星DNA的多态性。实验采用的18个微卫星标记位点在凉山半细毛羊群体中,平均等位基因数为8.2778个(3～19个),平均多态信息含量为0.591(0.253～0.833),遗传杂合度均值为0.500(0.026～0.888)。表明该品种绵羊遗传多态性丰富,群体遗传变异较大,并且所选18个微卫星基因座适用于绵羊的遗传连锁分析研究。 相似文献
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本研究以来自达里湖(碱水)和松花江(淡水)的瓦氏雅罗鱼(Leuciscus waleckii)杂交F2为实验材料,通过碱度耐受实验进行性状测定,以39对多态的EST-SSR和SSR为标记,对77个F2个体进行基因分型,根据Fisher确切概率法对F2基因型和耐碱性状进行关联分析。结果发现,有2个标记与耐碱性状显著相关(P0.05),其中1个标记为EST-SSR,从瓦氏雅罗鱼转录组数据库中调取该EST序列,基因注释结果显示该序列与团头鲂(Megalobrama amblycephala)低氧诱导因子HIF-3?基因、草鱼的低氧诱导因子HIF-4?基因具有很高的同源性。该基因的主要功能是参与鱼类的耐低氧反应过程,加强鱼类的耐低氧能力。本研究对于今后深入研究此功能基因的作用机制及培育适于盐碱水域养殖的鱼类新品种具有重要的意义。 相似文献
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The sequence-related amplified polymorphism (SRAP) technique was used to analyze the gene differentiation between two cultured
populations [Freshwater Fisheries Research Center (FFRC) and Qianzhou populations] and one wild population (Hanjian population)
of grass carp (Ctenopharyngodon idella). Some loci showed quite different genetic frequencies, attributable to artificial selection, which imply that these fragments
are putative markers of germplasm identification. We developed a simple and effective method to further characterize these
SRAP fragments. Specific SRAP bands were cut directly from polyacrylamide gels, re-amplified, cloned, and sequenced. Twenty-one
putative genetic markers were sequenced, ranging from 137 to 357 bp. The sequences were submitted to the database of the Genome
Sequence Survey. A BLAST analysis showed that eight SRAP fragments were highly similar to functional genes, whereas the other
13 had no similarity, indicating that these markers are tightly linked to the germ identification trait although only eight
are functional genes. Three primers were designed according to this sequence information and used for PCR amplification of
the three populations. A sequence-characterized amplified region (SCAR1) was positively amplified in the artificially cultured
populations but not in the wild population. The frequency of the SCAR3 marker in the cultured populations was 87% (26/174),
whereas it was only 6% (6/100) in the wild population. A specific band was isolated from all individuals in the wild population
with the SCAR3 primers, whereas the specific band was amplified from only seven individuals in the FFRC population and from
none of the Qianzhou population. The frequency of SCAR2 in the artificially cultured populations was 96.5%. These results
indicate that SCAR1 could be used as a specific molecular marker for population identification. The SCAR markers used in this
study offer a powerful, easy, and rapid method for genetic analysis and the discrimination of different populations. 相似文献
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将考力代绵羊离散繁殖性状配合阈模型,分别用单性状和多性状Gibbs抽样估计遗传力。多性状Gibbs抽样时,一次对两个性状进行抽样,遗传力最后取其平均值。并用多种方法对Gibbs链的收敛进行诊断。结果表明单性状和多性状分析下的产羔数、活羔数、受精力、妊娠维持和多胎性的遗传力分别为0.097±0.052、0.100±0.036、0.119±0.058、0.103±0.043、0.130±0.041和0.305±0.049、0.296±0.047、0.016±0.012、0.015±0.010、0.261±0.045。 相似文献
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荧光原位杂交fluorescence in situ hybridization,FISH）技术是一种简单而有效的染色体上物理定位DNA序列的技术。本文介绍了荧光原位杂交技术的基本原理以及实验流程,综述了近年来FISH技术在鱼类基因定位方面的应用,如来源于细菌人工染色体（bacterial artificial chromosome,BAC）文库的单拷贝基因的定位、核糖体基因和组蛋白基因等中度重复序列的定位、着丝粒特异序列和性别特异序列等高度重复序列的定位以及其他重复序列的定位等,用于研究特定基因定位、性染色体鉴定及种间杂交等遗传学问题,并展望了此技术在定位鱼类经济性状相关标记或基因、性别相关标记或基因及种特异染色体标记中的应用前景。 相似文献
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斑点叉尾鮰基因组的研究 总被引：1，自引：0，他引：1
作为重要的水产养殖种类之一,斑点叉尾(IctalurusPunctatus)的基因组学研究已经取得了较大进展。其众多遗传连锁图以及与表型性状有关的DNA分子标记和基因组资源已经建立;基因组中一些重要的重复片段,已经得到鉴定和辨别,这更有利于对斑点叉尾鮰基因组进行物理学分析;通过基因组学方法,获得了大量基因或全长cDNA序列、以及基因进化和与功能相关基因表达方面的信息。利用细菌人工染色体叠连群技术,创建斑点叉尾鮰基因组物理图谱,开发特定片段分子标记,进行数量性状基因位点(QTLs)分析和高密度基因组绘图。通过比较图谱,可以更有效地进行大范围EST分析和I型分子标记绘图。cDNA微阵列或基因芯片技术的利用,加快新基因发现和鉴定的步伐,为分子标记辅助育种和病害诊断与防治研究奠定了坚实基础。 相似文献