千万不忽视良种黄牛的保种问题

阐述了良种牛保种的重要意义，基因的随机漂移，选择与杂交，近交是特定基因从群体中消失的主要原因，群体及其有效含量和系统选育的科学组织是保种的重要内容，最后介绍我国良种牛的保种方法及其存在的问题，并提出解决的办法。     

畜禽保种群体大小和适宜性别比例的探讨

<正> 一个畜禽的保种群体应该有多大,群体中的公母畜比例多少为宜,这些都是“优化”保种方案需要解决的问题。为了使保种群体在相当长的一段时间内,主要性状和与其相关的性状的基因频率不发生太大的变化,就要在保种期内不与其他品种杂交,除淘汰不符合保种目标的个体外不作严格的选择,群体内进行随机交配或有意识避免高度的近交。 这里讨论的保种群体大小的前提是:群体内随机交配;100年内近交系数不超过0.1;大家畜(马、     

大额牛的群体生存现状与保种措施

本文阐述了大额牛的品种特性、种群现状和保种措施.大额牛保种可采用原产地活体保种,迁地活体保种和现代生物技术保种.大额牛体型较大,产肉性能好、行动敏捷、结构紧凑、肌肉发达、肉质优良、耐粗饲、适应性、繁殖力和抗病力均较强等特点.种群体数量极小.大额牛是云南省一个地方品种,保种工作刻不容缓.     

畜禽品种保存的最优规划

我国是一个畜禽品种资源丰富的国家,仅牛的品种就有约五十个,保存和利用好我国的品种资源,是科学工作者的一项重要任务。由于保种实际上是保存其品种的基因库,其关键在于控制群体过小所致的基因的随机漂移,以及近交系数的上升速率,因此,使群体有效含量有足够的大是保证保种成功的主要因素。但由于保种是一个长期的     

对郏县红牛的主动保种问题讨论

为了促进郏县红牛的保种安全性.通过对郏县红牛主产区牛群的调查,认识到在现代肉牛生产体系中,郏县红牛属于一个良好的母本品种,具有很多优良特性.提出要依据保种理论建立保种群体,尽量提高保种群体的安全性;以发展促进保种,不断选育提高,合理利用导入杂交.作者认为,主动保种是郏县红牛长期保种的有效途径.     

文山黄牛的现状与保种措施

文章阐述了文山黄牛的品种特性、现状和保种措施。文山牛保种可采用原产地活体保种,迁地活体保种和现代生物技术保种等多种方式。文山牛体型较大,性情温顺,产肉性能好、活动敏捷、结构紧凑、肌肉强健、肉品质优良、耐粗饲、适应性广、繁殖力和抗病力均较强等特点。文山牛是云南省一个地方良种,种质资源保护刻不容缓。     

地方畜禽品种保种方法的可行性浅析

1 前言 保种就是要保存一切与特定生态条件相联系的基因及基因组合体系.现有地方家畜品种的保种方法都是以群体遗传学理论为基础,尽量控制群体近交增量为原则,通过增大群体有效含量,确定合适的公母畜比例和留种方式,避免近亲交配及延长世代间隔来实现的.根据群体遗传学理论虽然可以指导地方畜禽品种的保种,对基因是否丢失及丢失的可能性作出估计,但无法知道其真实情况,加上保种资金投入有限,群体有效含量低,这样就不可避免地会出现优良基因的丢失.所以,现有的地方畜禽品种保种方法并不能有效地保存好已有的遗传资源.     

不同群体规模下闭锁群体遗传漂变的模拟

为了研究在施行随机留种、随机交配、世代不重叠、群体间个体无迁移、整个保种过程中基因不发生突变的原位保种群体中遗传漂变的变化情况,试验采用计算机模拟方法针对不同群体规模下闭锁群体基因频率、基因型频率在50个世代中的变化进行研究。结果表明:群体规模越大,基因频率、基因型频率在世代间波动的幅度越小,因此世代间随机遗传漂变基因被固定或丢失的概率越小。     

郏县红牛肉用新品系培育和高档牛肉开发思路

郏县红牛是我国八大肉牛良种之一,具有良好的特征特性和稳定的遗传性能,搞好郏县红牛的保种选育与开发利用具有非常重要的意义。本文以郏县红牛的发展及现状为基础,提出了郏县红牛新品系培育的技术路线、方向和方法.并就郏县红牛高档牛肉的开发提出了思路。     

河南省南阳市黄牛良种繁育场 [南阳牛(原种)]

南阳市黄牛良种繁育场又名南阳市黄牛研究所,专门从事南阳牛的保种育种及良种推广工作.     

Conservation priorities for the different lines of Dutch Red and White Friesian cattle change when relationships with other breeds are taken into account

From a genetic point of view, the selection of breeds and animals within breeds for conservation in a national gene pool can be based on a maximum diversity strategy. This implies that priority is given to conservation of breeds and animals that diverge most and overlap of conserved diversity is minimized. This study investigated the genetic diversity in the Dutch Red and White Friesian (DFR) cattle breed and its contribution to the total genetic diversity in the pool of the Dutch dairy breeds. All Dutch cattle breeds are clearly distinct, except for Dutch Friesian breed (DF) and DFR and have their own specific genetic identity. DFR has a small but unique contribution to the total genetic diversity of Dutch cattle breeds and is closely related to the Dutch Friesian breed. Seven different lines are distinguished within the DFR breed and all contribute to the diversity of the DFR breed. Two lines show the largest contributions to the genetic diversity in DFR. One of these lines comprises unique diversity both within the breed and across all cattle breeds. The other line comprises unique diversity for the DFR but overlaps with the Holstein Friesian breed. There seems to be no necessity to conserve the other five lines separately, because their level of differentiation is very low. This study illustrates that, when taking conservation decisions for a breed, it is worthwhile to take into account the population structure of the breed itself and the relationships with other breeds.     

渤海黑牛种群现状及其保种利用问题

渤海黑牛是肉役兼用的优良品种,被列为我国受保护的地方良种。本文重点介绍了渤海黑牛种群现状及存在的问题,并对渤海黑牛的保种途径与利用措施以及渤海黑牛的杂交改良与开发利用进行了归纳总结,认为以我国优良地方黄牛品种为基础,选育具有中国特色的黄牛肉用新品种,是我国肉牛保种及提高生产效益的必由之路,这对其它地方品种的保护与利用具有一定的借鉴意义。     

皮南牛新品种培育现状、存在问题与对策

南阳牛是我国五大良种黄牛品种之一,近些年国家越来越重视通过杂交改良的方法产生新品种培育工作,1986年引进了皮埃蒙特牛,与南阳牛进行杂交改良,通过30多年来的持续选育,横交固定形成了皮南牛新类群,它保持了南阳牛适应性好、耐粗饲的优点,同时继承了皮埃蒙特牛生长发育快、瘦肉率高的特点,但在皮南牛新品种培育过程中,仍存在核心...     

Analysis of genetic and cultural conservation value of three indigenous Croatian cattle breeds in a local and global context

It is widely accepted that autochthonous cattle breeds can be important genetic resources for unforeseeable environmental conditions in the future. Apart from that, they often represent local culture and tradition and thus assist in the awareness of ethnic identity of a country. In Croatia, there are only three indigenous cattle breeds, Croatian Bu?a, Slavonian Syrmian Podolian and Istrian Cattle. All of them are threatened but specialized in a particular habitat and production system. We analysed 93 microsatellites in 51 animals of each breed to get thorough information about genetic diversity and population structure. We further set them within an existing frame of additional 16 breeds that have been genotyped for the same marker set and cover a geographical area from the domestication centre near Anatolia, through the Balkan and alpine regions, to the north‐west of Europe. The cultural value was evaluated regarding the role in landscape, gastronomy, folklore and handicraft. The overall results recognize Croatian Bu?a being partly admixed but harbouring an enormous genetic diversity comparable with other traditional unselected Bu?a breeds in the Anatolian and Balkan areas. The Podolian cattle showed the lowest genetic diversity at the highest genetic distance to all remaining breeds but are playing an important role as part of the cultural landscape and thus contribute to the tourist industry. The genetic diversity of the Istrian cattle was found in the middle range of this study. It is already included in the tourist industry as a local food speciality. Current and future conservation strategies are discussed.     

河南省肉牛遗传育种现状以及对策建议

河南省的南阳牛、郏县红牛是由河南省经过长期不断选育而形成的地方优良品种。近年来,由于牛肉需求的不断加大以及对牛肉品质要求的提高,同时由于河南肉牛的遗传改良基础好,培育具有优良肉质的新品种成为当前河南省育种产业的首要任务,与此同时,河南肉牛产业也凸显了一些新的问题。因此,本文综述了河南省肉牛遗传育种现状、遗传育种相关研究进展以及遗传育种存在的问题,从而为下一步河南省地方牛种质研究及创新利用提供对策建议。     

通辽地区科尔沁肉牛新品种（品系）培育方案

为尽快解决通辽地区无自主知识产权的肉牛品种的问题,提高本地区牛群肉用生产性能,制定了科尔沁肉牛新品种(类群)培育方案。本方案是在科尔沁牛基础上采取常规育种技术与现代分子遗传育种技术相结合的技术手段对肉用性状进行选育,培育肉牛新品种。育种方案包括新品种定向、育种任务、预期指标、育种方法及技术措施。     

关于地方品种牛资源保护的思考

近年来,人们对地方品种牛资源保护的重要性和迫切性已有基本的共识,但在一些具体问题的处理上,特别是在保种的具体方法和措施方面,不同的观点是存在一些分歧的。笔者根据工作实际,对地方品种牛的保种目标、选育保种、保种方式以及开发利用等方面进行了认真思考。     

中国4个培育肉牛品种发展现状及存在问题的对策与建议

随着我国经济水平迅速增长,肉牛产业生产需求也越来越大。截至2015年底,我国自主培育了4个优秀肉牛品种,为肉牛产业带来了一定的经济效益。但是,由于我国肉牛产业起步较晚,新品种虽然相比于原来的肉牛品种有进步,但仍然面临许多问题。本文就夏南牛、延黄牛、辽育白牛、云岭牛4个自主培育品种的生产现状、存在问题和对策进行论述,并对肉牛产业发展前景进行了展望。     

Pedigree analysis in the Brazilian Zebu breeds

Zebu breeds play an important role in cattle production systems in Brazil. To assess the genetic variability from animals in the Herd Books of Nelore, Gir and Guzerat breeds, generation intervals, inbreeding, effective population size and parameters of gene origin (effective number of founders, ancestors and founder genomes) were calculated using pedigree records from 1938 to 1998. Breed subdivision was quantified by Wright's F -statistics. Calculations were separately carried out for consecutive 4-year intervals in the period 1979–98. Generation interval was around 8 years for the three breeds. Total inbreeding increased in all the breeds reaching values of 2.13%, 2.28% and 1.75%. Effective population size decreased from 85 to 68 in Nelore, from 70 to 45 in Gir and remained nearly constant around 104 in Guzerat. The quantities assessing the number of contributing ancestors decreased with time in all the breeds, and in the last analysed period the most important ancestor accounted for 14%, 3.1% and 4.1% in Nelore, Gir and Guzerat, respectively. Results indicate that the studied breeds are suffering from a loss of genetic variability which can result in negative effects on breeding and conservation purposes.     

Population Structure and Genetic Diversity of Seven Chinese Indigenous Chicken Populations in Guizhou Province

To investigate the population structure and genetic diversity of indigenous chicken breeds in Guizhou, a total of 150 individual samples were collected from 12 breeds, including seven local chicken breeds in Guizhou Province, three Chinese native breeds found in other provinces, and two commercial breeds. The genotype datasets were obtained using a 50K single nucleotide polymorphism array method, and then a series of population analyses were performed. The obtained population parameters and linkage disequilibrium decay indicated a higher degree of genetic diversity in Guizhou chickens than in commercial breeds. Two Guizhou local breeds, Wumeng black-bone and Weining, were clustered with a breed from a neighboring province, Xinwen black-bone, which exhibited similar ancestral composition patterns. A newly found breed, Wumeng crested, had high genetic diversity and displayed genetic differences from other Guizhou breeds. These findings provide insight into the establishment of efficient conservation and utilization programs for Guizhou chicken breeds.