牦牛遗传育种学研究

本文在分析牦牛遗传资源特点的基础上,综合评述了近二十年来牦牛遗传育种学的研究现状,指出了含后的研究方向。     

遗传标记及其在动物遗传育种中的应用（上）

本文综述了几种常用的遗传标记方法及其各自的优缺点，以及遗传传标记在动物遗传育种中的应用同状，着重对分子生物学标记作了较系统的阐述。     

遗传标记在苜蓿遗传多样性研究中的应用

介绍了当前广泛应用的苜蓿遗传多样性研究技术及其研究现状,包括苜蓿Medicago形态学和等位酶分析、种质资源和种内杂合性、进化与亲缘关系、抗逆性以及遗传连锁作图等几个方面的研究概况,同时提出了今后苜蓿遗传多样性分子标记研究的重点发展方向.     

肌苷酸的遗传研究进展

本文主要概述了动物肉品内肌苷酸含量的遗传差异、遗传参数及相关分子遗传标记的研究进展,并指出了未来的研究方向.     

遗传标记及其发展概述

本文综述了遗传标记方法及其优点和不足，重点对RFLPs、Microsatellite DNA、RAPD、AFLPs、SNPs等几种主要的分子遗传标记作了较全面的概述。     

遗传标记的研究进展

生物化学和分子生物学的快速发展使用于育种的遗传标记经历了不同的发展阶段，本文对不同的遗传标记进行了较详尽的分类和描述。     

分子遗传标记在家禽遗传距离估测中的应用

近几十年来，我国由于保种措施不当和盲目的引进外来品种进行杂交，从而导致家禽品种资源日益减少，品种失去了其丰富的遗传多样性，特别是一些隐性遗传的优势基因的丢失，而进行畜禽品种的遗传距离测定和聚类分析是畜禽多样性估测、利用和保护的基础性工作，因此，测定畜禽物种内各品种间的遗传距离，为保种对象的确定提供依据成为目     

牛属遗传多样性及种间的遗传分化研究进展（下）

牛属遗传多样性及种间的遗传分化研究进展（下）涂正超邱怀（西北农业大学动物科学系陕西杨陵７１２１００）４牛种间的ｍｔＤＮＡ遗传分化线粒体ＤＮＡ（ｍｔＤＮＡ）为核外遗传物质,以母系遗传方式遗传,序列简单,核苷酸岐异度大,在种间、近缘种间具有丰富的遗传多...     

遗传标记及其发展概述

本文综述了遗传标记方法及其优点和不足,重点对RFLPs、Microsatellite DNA、RAPD、AFLPs、SNPs等几种 主要的分子遗传标记作了较全面的概述。     

蜜蜂遗传标记研究进展

遗传学将可识别的等位基因称为遗传标记。传统的遗传学研究和育种工作主要是借助形态学、细胞学和生理生化指标等遗传标记来进行的。就蜜蜂而言，多数遗传标记是根据生物学性状的形成而进行判别，检测时基本要以活体形式，如蜜蜂的抗病基因是以人工饲养的蜂群抗病力强弱为标记，抗螨     

Evaluating breeding objectives for sow productivity and production traits in Large White Pigs

the objective of the study was to develop and evaluate different breeding objectives for sow productivity and for production traits, using economic selection indices. Genetic parameters were generated using a repeated records model for sow productivity traits and a maternal effects model for production traits, in ASREML. Stochastic simulation models based on a hypothetical 100-sow model were performed for each line, i.e., a dam line and a terminal sire line, respectively, to derive economic values. The traits included in the study were number born alive (NBA), 21-day litter size (D21LS), 21-day litter weight (D21LWT), average daily gain (ADG), feed conversion ratio (FCR), age at slaughter (AGES), dressing percentage (DRESS), lean content (LEAN) and backfat thickness (BFAT). The economic values for LEAN and BFAT were derived using the partial differentiation of the profit function, while those for the other traits were derived using the partial budget approach. An economic value of a trait was the change in profit per unit genetic change in that trait. Breeding objectives were developed with a corresponding selection index, for improvement of that objective. Three combinations of breeding objectives and selection indices were developed for sow productivity traits, while there were 15 combinations for production traits. Responses to selection and economic return were computed for each combination to determine the most appropriate combination for the improvement of the breeding objective traits. The most appropriate index to improve sow productivity consisted of NBA and D21LWT. For production traits, the combination that consisted of a selection index with AGES, DRESS and BFAT, and the breeding objective ADG, DRESS, FCR and LEAN, was considered the most appropriate. Age at slaughter and BFAT were, respectively, included as indicator traits for ADG and LEAN. The recommended breeding objectives were sensitive to changes in economic values, indicating that economic values for breeding goal traits should be updated periodically to ensure proper weighting of traits, hence maximization of economic return.     

性别对约克夏猪的主要经济性状遗传参数估计的影响

本文采用动物模型DFREML ,对位于韩国京畿道二川郡的某原种猪场的 6 16 8头鉴定的约克夏猪的资料进行了性别对约克夏猪主要经济性状的遗传参数影响的研究。结果表明 :约克夏猪主要经济性状的最小二乘均值在公母猪之间有明显差异 (P <0 .0 5 ) ;模型中同时考虑母体效应时得到的遗传力均低于没有考虑母体效应时的遗传力。同时 ,将性别视为固定效应时各性状间的遗传相关高于只考虑公猪时各性状间的遗传相关 ,但低于只考虑母猪时各性状间的遗传相关     

苏博美利奴羊主要经济性状的遗传参数估计

苏博美利奴羊是我国近年来培育出的超细型细毛羊品种,为了解该品种主要经济性状的遗传参数以及群体改变的速度和方向,本研究收集2014—2020年新疆巩乃斯种羊场苏博美利奴羊的周岁母羊鉴定记录共计9140条、剪毛称重记录共计7158条以及初生重记录5540条;利用DMU软件采用AIREML模块结合EM算法配合单性状动物模型估...     

A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep

Genetic parameters for a range of sheep production traits have been reviewed from estimates published over the last decade. Weighted means and standard errors of estimates of direct and maternal heritability, common environmental effects and the correlation between direct and maternal effects are presented for various growth, carcass and meat, wool, reproduction, disease resistance and feed intake traits. Weighted means and confidence intervals for the genetic and phenotypic correlations between these traits are also presented. A random effects model that incorporated between and within study variance components was used to obtain the weighted means and variances. The weighted mean heritability estimates for the major wool traits (clean fleece weight, fibre diameter and staple length) and all the growth traits were based on more than 20 independent estimates, with the other wool traits based on more than 10 independent estimates. The mean heritability estimates for the carcass and meat traits were based on very few estimates except for fat (27) and muscle depth (11) in live animals. There were more than 10 independent estimates of heritability for most reproduction traits and for worm resistance, but few estimates for other sheep disease traits or feed intake. The mean genetic and phenotypic correlations were based on considerably smaller numbers of independent estimates. There were a reasonable number of estimates of genetic correlations among most of the wool and growth traits, although there were few estimates for the wool quality traits and among the reproduction traits. Estimates of genetic correlations between the groups of different production traits were very sparse. The mean genetic correlations generally had wide confidence intervals reflecting the large variation between estimates and relatively small data sets (number of sires) used. More accurate estimates of genetic parameters and in particular correlations between economically important traits are required for accurate genetic evaluation and development of breeding objectives.     

高山美利奴羊重要经济性状遗传参数估计

本研究旨在估计高山美利奴羊重要经济性状的遗传参数,为优化高山美利奴羊选育方案、建设品种完整结构、进行遗传评估及实施育种值选种提供理论技术支撑。采用甘肃省绵羊繁育技术推广站2003—2018年高山美利奴羊核心群数据资料,基于ASReml运用单性状个体动物模型和多性状个体动物模型估计高山美利奴羊体重、产羔数、产毛量、净毛量、净毛率、羊毛纤维直径、羊毛纤维直径变异系数、毛丛长度等重要经济性状的遗传参数。结果表明:高山美利奴羊产羔数为低等遗传力,其他所有性状均为中高等遗传力;大部分经济性状间呈正遗传相关,体重、产毛量、羊毛纤维直径与净毛率间呈负遗传相关,羊毛纤维直径变异系数与体重、产毛量、纤维直径呈负遗传相关。     

牛遗传图谱的研究进展

20世纪90年代以来,牛遗传图谱发展非常迅速。到目前为止,已经公布了几个版本的遗传图谱。在图谱上DNA标记不断增加,标记间隔越来越小,但是目前图谱还是存在着标记密度不均匀等问题。随着牛基因组计划的完成,基因组学和QTL定位的发展,尤其是表达序列标签（EST）在图谱构建中的应用,牛的遗传图谱将更加完善,为重要经济性状的基因定位和基因克隆奠定了基础。     

Genetic correlations between competition traits and traits scored at breeding field-tests in Icelandic horses

Relationships between breeding field-test traits and competition traits were studied to investigate whether the latter could be usefully included in the genetic evaluation of Icelandic horses. The current method of genetic evaluation is based on records from breeding field-tests only. The breeding field-test data included 16 401 individual records of Icelandic horses evaluated in 11 countries during 1990–2005. Competition results included 18 982 records of 3790 horses competing in sport and gæðinga competitions in Iceland and Sweden during 1998–2004. In the breeding field-tests, eight conformation traits and eight riding ability traits were scored; height of withers was also recorded. These traits were analysed together with the competition traits tölt(comp), 4-gait, 5-gait and pace test, in bivariate analyses. Animal models were used; the fixed effects for breeding field-test traits included sex by age interaction and country by year interaction. For the competition traits the model included fixed effects of sex, age and event, and a random permanent environmental effect. Estimated heritabilities and genetic correlations for breeding field-test traits were consistent with earlier results; heritabilities ranged from 0.20 to 0.67, and moderate to high genetic correlations were estimated between many of the riding ability traits, and between riding ability traits and some conformation traits. The estimated heritabilities for competition traits were about 0.20, and genetic correlations between competition traits varied from − 0.12 to 1.00. In general, high genetic correlations were estimated between breeding field-test riding ability traits and competition traits. Moderately positive genetic correlations were found between some breeding field-test conformation traits and competition traits. Competition traits add information relating to the breeding goal of the Icelandic horse; they should therefore be added to genetic evaluation in future.     

国外生猪育种体系简析及对我国生猪育种的几点思考

选择是生猪育种的核心,而准确地选择和选种依赖于完善和成熟的育种体系。国际养猪发达国家(国际育种企业)对育种体系不断完善,长期进行生长、繁殖和肉品质等各类性状的表型测定,运用多场联合评估和基因组选择等方法不断提高遗传评估的准确性,不断挖掘新的育种性状,并进行测定、评估和选育,实现了种猪群体持续的遗传改良和综合性能的不断提升。本文对欧美发达国家(国际育种企业)的生猪育种技术体系进行了综述,以期为我国的生猪育种工作提供参考,并促进我国生猪种业的创新发展。     

牛奶的中红外光谱相关指标及遗传规律研究进展

中红外光谱分析技术(MIRS)作为一种快速且经济的检测手段广泛应用于生产,中红外(MIR)光谱在本质上可以反映牛奶特征。MIR光谱整体上是一条具有低中高遗传力的曲线,但并非所有MIR区域都具有遗传意义,应深入挖掘光谱数据具有的高遗传变异,提取可用于遗传育种的有效区域,得到筛选光谱信息区域的最佳方法。在标准预测模型基础上,获得的牛奶组分预测值具有遗传变异性,总体上呈中高遗传力,可进行遗传选择或对相关性状进行间接选择;借助MIRS挖掘一些新型经济性状。本文对牛奶MIR光谱相关指标遗传规律进行综述,以期为选种选育提供理论基础。     

Estimates of (co)variance components and genetic parameters for body weights and first greasy fleece weight in Malpura sheep

Estimates of (co)variance components and genetic parameters were calculated for birth weight (BWT), weaning weight (WWT), 6 month weight (6WT), 9 month weight (9WT), 12 month weight (12WT) and greasy fleece weight at first clip (GFW) for Malpura sheep. Data were collected over a period of 23 years (1985–2007) for economic traits of Malpura sheep maintained at the Central Sheep & Wool Research Institute, Avikanagar, Rajasthan, India. Analyses were carried out by restricted maximum likelihood procedures (REML), fitting six animal models with various combinations of direct and maternal effects. Direct heritability estimates for BWT, WWT, 6WT, 9WT, 12WT and GFW from the best model (maternal permanent environmental effect in addition to direct additive effect) were 0.19 ± 0.04, 0.18 ± 0.04, 0.27, 0.15 ± 0.04, 0.11 ± 0.04 and 0.30 ± 0.00, respectively. Maternal effects declined as the age of the animal increased. Maternal permanent environmental effects contributed 20% of the total phenotypic variation for BWT, 5% for WWT and 4% for GFW. A moderate rate of genetic progress seems possible in Malpura sheep flock for body weight traits and fleece weight by mass selection. Direct genetic correlations between body weight traits were positive and ranged from 0.40 between BWT and 6WT to 0.96 between 9WT and 12WT. Genetic correlations of GFW with body weights were 0.06, 0.49, 0.41, 0.19 and 0.15 from birth to 12WT. The moderately positive genetic correlation between 6WT and GFW suggests that genetic gain in the first greasy fleece weight will occur if selection is carried out for higher 6WT.