我国羊和猪的新品种

家畜新品种的培育是经过人们有意识、有明确选择目标和在一定环境、饲养条件下培育出来的。我国家畜新品种的形成,主要采用由国外引入的优良品种与我国生产性能较低的品种进行杂交,经过选择理想型的杂种互交、自群繁育而形成新品种。多年来我国重点培育了一批新品种。在绵羊方面有新疆细毛羊、东北细毛羊、内蒙古细毛羊、甘肃高山细毛羊、敖汉细毛羊、中国美利奴羊等。在山羊方面有关中奶山羊、崂山奶山羊等。在猪种方面有哈白猪、新金猪、东北花猪、新淮猪、上海白猪、伊犁白猪、汉中白猪、赣州白猪、北京黑猪、山西黑猪、泛农花猪、三江白猪等10余个新猪种。现扼要分别介绍以下品种:     

FUT1基因多态性及其与产仔性状的关联性研究

采用PCR-RFLP技术6个中外品种共245头猪的FUT1基因进行了研究, 结果表明, Hin 6Ⅰ位点上, 大白猪、长白猪和杜洛克猪3个外来猪种均存在多态, 且以敏感型(GG型和AG型)居多; 山西黑猪、太原花猪和马身猪3个本地猪种的所有检测样品都表现为GG型。用方差分析方法分析FUT1基因型、品种和胎次与产仔性状之间的关系, 基因型和品种对猪的总产仔数的影响显著, 胎次对总产仔数影响不显著。而基因型、品种和胎次对产活仔数影响均不显著。     

猪Pit-1基因多态性及其与生长性状的关联分析

利用现代分子标记技术寻找影响猪生长性状的标记基因座,为应用标记辅助选择培育高生产性能猪的品种或品系提供帮助。本试验采用PCR-RFLP(RsaⅠ限制性内切酶)分子标记技术,分析了杜洛克、长白、大白及长大二元杂交4个品种共381头猪Pit-1基因exon 5至intron 5内多态性,并采用最小二乘法分析了Pit-1基因多态性对生长性状影响的遗传效应。经检测,4个品种Pit-1基因RsaⅠ位点均存在多态性。等位基因A的基因频率分别为0.831 7、0.830 2、0.676 7、0.752 3,A为优势基因。被测猪群Pit-1基因的基因频率在被测猪群中均处于Hardy-Weinberg平衡状态(p0.05)。最小二乘分析表明:Pit-1基因3种基因型的猪在出生重、断奶重及70日龄重性状上均呈现BBABAA趋势(其中,长白猪只存在AB,AA 2种基因型),B为优势基因。Pit-1基因exon 5至intron 5 RsaⅠ位点多态性对测试猪群生长性状有一定影响,但是否是影响生长性状的一个候选基因之一或是与影响猪生长性状的QTL连锁的基因,还需进一步研究。     

应用Weitzman方法分析华中型猪品种的遗传多样性

本文根据华中型20个猪品种27个微卫星DNA标记的研究数据, 应用Weitzman方法, 即通过估计总体遗传多样性、期望多样性、品种对总体遗传多样性的贡献、边际遗传多样性、保种潜力等指标, 评估华中型20个猪品种的遗传多样性, 并通过构建品种间遗传多样性的最大似然树, 图示化展示20个品种间遗传多样性的相互关系。20个华中型猪品种的总体遗传多样性是11,707, 期望多样性占总的遗传多样性的66.96%, 金华猪、皖南花猪、嵊县花猪和乐平猪是对总体遗传多样性贡献最大的4个品种, 其贡献率分别是8.90%、7.46%、7.40%和7.04%, 保种潜力最大的4个品种分别是金华猪、嵊县花猪、杭猪和大花白猪。根据遗传多样性进行聚类分析, 大致可将华中型猪分为3类: 大围子猪、沙子岭猪、宁乡猪等分布于湖南、湖北的品种为一类; 南城猪、嵊县花猪与杭猪聚成另一类; 金华猪与皖南花猪单独聚成一类。研究结果可为我国华中型地方猪种遗传多样性的最大化保护和利用提供科学决策依据, 本文也对Weitzman方法在应用中的关键性问题进行了探讨。     

湖北省三品种猪27个微卫星座位的遗传变异

采用国际动物遗传学会（ISAG）和联合国粮农组织（FAO）共同推荐的27个微卫星标记,对湖北省3个主要地方猪种（通城猪、清平猪和阳新猪）的遗传变异进行了检测。计算出各个品种的基因杂合度、各个座位的多态信息含量及品种间的遗传距离。结果表明,3个地方猪种的平均基因杂合度分别为0.7489、0.6987和0.6273,遗传多样性比较丰富;通城猪和清平猪亲缘关系较近,而两者与阳新猪亲缘关系略远。     

中国地方猪ESR基因PvuⅡ多态性及其与产仔数的关系

四川农业大学李明洲等4位研究人员试验采用PCR-RFLPs方法,研究了中国成华猪、内江猪和太湖猪3个地方品种ESR基因的多态性及其与产仔数间的关系。结果表明:成华猪、内江猪、太湖猪的B等位基因频率分别为0.6389、0.6613、0.6855。在这3个猪品种中,除成华猪检测时只有AB、BB两种基     

用RAPD标记中国小型地方猪品种的遗传多样性

在我国大型品种猪肉全部占领市场和改变肉食品结构的今天,我国地方品种的小型猪家畜资源显得十分宝贵,诸如香猪、滇南小耳猪、五指山猪、藏猪等,特别对它们的分子遗传研究就更是迫近眉梢。目前华中农业大学动物科技学院动物分子生物学与育种实验室樊斌博士等8位专家教授采用随机扩增多态DNA(Randomamplified palymorphic DNA,RAPD)法,在周俊玲等和刘德武等人对其他猪遗传变异的检测与分析和猪群体结构的基础上,采集了4种小型猪、二花脸猪和杜洛克猪的血液样品,应RAPD进行检测,所得数据进行统计分析并制成品种间NJ聚类图。樊斌博士选…     

多仔猪—太湖猪

太湖猪为长江下游数量多和分布较广的一个地方猪种，具有性成熟早，产仔率高，遗传性强肉质鲜美，杂交效果显著，对青粗饲料利用率高等特点，品种内类群结构丰富，有广泛的遗传基础，今后对该品种应加强品种选育，提高瘦肉率，在商品瘦肉猪生产中更好的发挥作用。     

56个中国地方猪种微卫星基因座的遗传多样性

采用FA0—ISAG联合推荐的27个微卫星DNA标记对56个中国地方猪品种和3个引进猪种(杜洛克猪、长白猪、大白猪)进行遗传多样性分析,通过计算等位基因频率、有效等位基因数、平均遗传杂合度、基因分化系数、多态信息含量和遗传距离并进行系统聚类分析,评估其种内遗传变异和种间遗传关系。以聚类结果为基础,将56个中国地方猪种分为12类：Ⅰ、Ⅱ和Ⅲ类都是《中国猪品种志》中的华北型猪种;Ⅳ类相当于其中的江海型猪种;Ⅴ、Ⅵ、Ⅶ、Ⅷ和Ⅸ类的品种大部分属于华中型;Ⅹ和Ⅺ类相当于华南型品种;Ⅻ类相当于西南型品种。提出保种场结合保护区是一种比较符合我国地方猪种实际状况的保种模式。研究结果可为我国地方猪种种质特性研究提供基础数据,为我国地方猪品种资源的合理保护和利用提供科学依据。     

实验用小型猪营养需要研究进展

随着小型猪实验动物化研究的不断进步,小型猪作为生命科学研究的实验动物越来越受到人们的重视,因此生产标准化的小型猪至关重要,而对小型猪营养需要的了解和饲料标准的制定是生产标准化小型猪的重要基础之一。本文就小型猪的国内、外品种,小型猪的消化代谢特点以及对能量、蛋白质、矿物质及粗纤维营养需要的研究进展进行综述。     

Opportunities to improve nutrient efficiency in pigs and poultry through breeding

Efficiency of food and nutrient (including energy) use are considered the key factors in the economic and environmental performance of livestock systems. The aim of this paper is to consider the basis of genetic variation in the components that constitute dietary nutrient efficiency; and to conclude whether there would be benefit, in any relevant terms, in including these components in breeding programmes that aim to improve nutrient efficiency within pig and poultry systems of production. The components considered are (i) external, pre-ingestion losses, such as food spillage and its relation to feeding behaviour traits, (ii) digestive efficiency, (iii) maintenance requirements, (iv) net efficiency of energy and nutrient utilisation and (v) partitioning of scarce resources within productive and between productive and fitness functions. It is concluded that opportunities to exploit genetic variation exist mainly in the potential to improve the digestive efficiency of pigs and to reduce the maintenance requirements for resources mainly in hens, but also potentially in pigs. Current evidence suggests that there are very weak genetic and phenotypic correlations between components of feeding behaviour and productive traits, and little genetic variation in the net efficiency of nutrient utilisation among poultry and pig genotypes. The implication of the latter is that there would be little exploitable genetic variation in the partitioning of scarce nutrients between productive functions. Currently, there is a lack of understanding of the genetic basis of the partitioning of scarce nutrients between productive and fitness functions, and how this may impact upon the efficiency of nutrient use in pig and poultry systems. This is an area of research to which further effort might usefully be devoted.     

The effect of QTL-rich region polymorphisms identified by targeted DNA-seq on pig production traits

The aim of the present study was to analyse the effect of PLCD4, PECR, FN1 and PNKD mutations on pig productive traits and tested the usefulness of targeted enrichment DNA sequencing method as tool for preselection of genetic markers. The potential genetic markers for pig productive traits were identified by using targeted enrichment DNA sequencing of chromosome 15 region that is QTL-rich. The selected mutations were genotyped by using HRM, Sanger sequencing and PCR-ACRS methods. The association study was performed by using GLM model in SAS program and included over 500 pigs of 5 populations maintained in Poland. The variation (C/T) of PLCD4 gene affected feed conversion, intramuscular fat and water exudation. The PNKD mutations were associated with texture parameters measured after cooking. In turn, the variation rs792423408 (C/T) in the FN1 gene influenced toughness measured in semimembranosus muscle and growth traits that was observed particularly in Duroc breed. Summarizing, the investigated gene variants delivered valuable information that could be used during developing SNP microarray for genomic estimated breeding value procedure in pigs. Moreover, the study showed that the TEDNA-seq method could be used to preselect the molecular markers associated with pig traits. However, the further association study that included large number animal populations is necessary.     

A systematic literature mapping and meta-analysis of animal-based traits as indicators of production diseases in pigs

The choice of animal-based traits to identify and deal with production diseases is often a challenge for pig farmers, researchers and other related professionals. This systematic review focused on production diseases, that is, the diseases that arise from management practices, affecting the digestive, locomotory and respiratory system of pigs. The aim was to classify all traits that have been measured and conduct a meta-analysis to quantify the impact of diseases on these traits so that these can be used as indicators for intervention. Data were extracted from 67 peer-reviewed publications selected from 2339 records. Traits were classified as productive (performance and carcass composition), behavioural, biochemical and molecular traits. A meta-analysis based on mixed models was performed on traits assessed more than five times across studies, using the package metafor of the R software. A total of 524 unique traits were recorded 1 to 31 times in a variety of sample material including blood, muscle, articular cartilage, bone or at the level of whole animal. No behavioural traits were recorded from the included experiments. Only 14 traits were measured on more than five occasions across studies. Traits within the biochemical, molecular and productive trait groups were reported most frequently in the published literature and were most affected by production diseases; among these were some cytokines (interleukin (IL) 1-β, IL6, IL8 and tumour necrosis factor-α), acute phase proteins (haptoglobin) and daily weight gain. Quantification of the influence of factors relating to animal characteristics or husbandry practices was not possible, due to the low frequency of reporting throughout the literature. To conclude, this study has permitted a holistic assessment of traits measured in the published literature to study production diseases occurring in various stages of the production cycle of pigs. It shows the lack of consensus and common measurements of traits to characterise production diseases within the scientific literature. Specific traits, most of them relating to performance characteristics or immunological response of pigs, are proposed for further study as potential tools for the prognosis and study of production diseases.     

Association of pig UCP3 gene mutations and back fat thickness in the sixth and seventh rib

Accumulated studies have documented extensive links between UCP3 polymorphisms and pig productive traits, and quantitative trait loci linkage results, on the other hand, provided extensive evidences showing that UCP3 was in the core of several QTLs for carcass and meat quality traits. In this research, we screened two substitutions in coding sequence and one 9-base continuous mutated site in 3′UTR of pig UCP3 gene using the reference population of 293 pigs which were F ₂ generation of hybrids between Chinese native Jinhua pigs and European Pietrain. The two missense mutations of G1406A in Exon 3 and T3602C in Exon 5 which led to changes in the G150R and M259T, respectively, were digested by SmaI and introduced Tth111I separately for genotype analysis, and the 9-base continuous mutated site in the 3′UTR was analyzed by an AvaI cleavage. As a result, the 9-base continuous mutated site of 3′UTR manifested significantly close association with the backfat thickness at the sixth and seventh rib, but the polymorphisms of G1406A and T3602C were not associated significantly with any of the seven carcass traits. The same results were shown by RT-qPCR and western blotting. These findings inferred that UCP3 probably has tissue-specific effects on pig carcass traits.     

藏猪繁殖性状多基因效应分析

藏猪是我国特有的高原型地方猪种, 具有适应高海拔恶劣气候环境、抗病、耐粗、肉质鲜美等特点, 但繁殖力低。文章以促卵泡素b亚基(FSHb)、雌激素受体(ESR)、促乳素受体(PRLR)和视黄醛结合蛋白4(RBP4)等基因作为繁殖性状主要候选基因, 测定76头藏猪的基因型, 分析单基因和多基因合并对繁殖性状的影响效应。结果说明, 在藏猪群体中, FSHb、ESR和PRLR基因不同基因型繁殖性状差异显著, 优良基因型分别为BB、BB和AA。藏猪RBP4基因只有2种基因型, 对繁殖性状影响不显著。FSHb-ESR-PRLR基因的合并优良基因型为BB-BB-AA, 多基因聚合效应高于单基因效应。     

ETph: enhancers and their targets in pig and human database

Enhancers, as the genomic non-coding sequences, play a key role in the activation of gene expression. They have been widely identified in the human genome. Pig is an important biomedical model for human health. Few studies have been performed to explore the enhancers in the pig genome. The human enhancer information may be useful to identify enhancers in the pig genome. In addition, the genetic background of pig traits could be useful to annotate human enhancers and diseases. Thus, in order to further study enhancers and their potential roles in human and pig, we developed a public database, ETph (Enhancers and their Targets in pig and human). ETph integrates the information on human enhancers, pig putative enhancers, target genes, pig QTL terms, human diseases, GO terms and the KEGG pathway. A total of 25 182 enhancers were identified in the pig genome using the human homology sequence information. Among them, 6232 high-confidence enhancers were used to build the ETph. ETph provides a convenient platform to search, browse and download data. Moreover, a web-based analytical tool was designed to visualize networks and topology graphs among pig putative enhancers, target genes, pig QTL traits and human diseases. ETph might provide a useful tool for researchers to investigate the genetic background of pig traits and human diseases. ETph is freely accessible at http://klab.sjtu.edu.cn/enhancer/ .     

猪FUT1基因对肉质和胴体性状的影响

测定139头杂交猪(大白猪和梅山猪)的14个肉质性状和8个胴体性状,用PCR-RFLP方法检测FUT1基因型。分析猪FUT1基因型间肉质和胴体性状差异,发现AA基因型猪3个部位肌肉pH值均比AG基因型的高,其中pH(LD)达到显著水平(P<0.05)。AA基因型猪肌肉系水力显著高于AG猪的系水力(91.02% VS 86.70%,P<0.05)。AA基因型猪的肉色值显著高于AG猪的(P<0.05)。AA基因型猪三个部位肌肉膘厚值均较低,其中最后肋骨膘厚和倒数三四肋骨膘厚分别比AG基因型猪的低4.26 mm和3.96 mm(P<0.05)。AA基因型猪瘦肉率比AG基因型猪的高3.31% (53.46% VS 50.15%,P<0.05)。以上结果表明FUT1基因的AA基因型对肉质和和胴体性状具有显著的正遗传效应,这对于在抗病育种中应用该基因十分有利。     

藏猪3个繁殖性状主效基因多态性研究

藏猪是我国高海拔特有猪种,为了解藏猪繁殖性能的遗传潜力和基因多样性,利用PCR－RFLP技术测定了202头藏猪ESR、FSHβ和PRLR 3个繁殖性状主效基因位点的基因型多态性,并与文献报道的国内外猪种进行比较。结果显示藏猪群体ESR、FSHβ和PRLR优势基因型分别为BB型、AB型和AA型,3个位点基因型分布均符合哈迪－温伯格平衡。藏猪群体3个繁殖性状主效基因位点都有报道的有利基因型,且有利等位基因频率较高,说明藏猪在这3个基因位点可能具有优良繁殖性能的遗传潜力。     

Importance of adaptation and genotype × environment interactions in tropical beef breeding systems

This paper examines the relative importance of productive and adaptive traits in beef breeding systems based on Bos taurus and tropically adapted breeds across temperate and (sub)tropical environments. In the (sub)tropics, differences that exist between breeds in temperate environments are masked by the effects of environmental stressors. Hence in tropical environments, breeds are best categorised into breed types to compare their performance across environments. Because of the presence of environmental stressors, there are more sources of genetic variation in tropical breeding programmes. It is therefore necessary to examine the genetic basis of productive and adaptive traits for breeding programmes in those environments. This paper reviews the heritabilities and genetic relationships between economically important productive and adaptive traits relevant to (sub)tropical breeding programmes. It is concluded that it is possible to simultaneously genetically improve productive and adaptive traits in tropically adapted breeds of beef cattle grazed in tropical environments without serious detrimental consequences for either adaptation or production. However, breed-specific parameters are required for genetic evaluations. The paper also reviews the magnitude of genotype × environment (G × E) interactions impacting on production and adaptation of cattle, where 'genotype' is defined as breed (within a crossbreeding system), sire within breed (in a within-breed selection programme) or associations between economically important traits and single nucleotide polymorphisms (SNPs - within a marker-assisted selection programme). It is concluded that re-ranking of breeds across environments is best managed by the use of the breed type(s) best suited to the particular production environment. Re-ranking of sires across environments is apparent in poorly adapted breed types across extreme tropical and temperate environments or where breeding animals are selected in a temperate environment for use in the (sub)tropics. However, G × E interactions are unlikely to be of major importance in tropically adapted beef cattle grazed in either temperate or (sub)tropical environments, although sex × environment interactions may provide new opportunities for differentially selecting to simultaneously improve steer performance in benign environments and female performance in harsher environments. Early evidence suggests that re-ranking of SNPs occurs across temperate and tropical environments, although their magnitude is still to be confirmed in well-designed experiments. The major limitation to genetic improvement of beef cattle over the next decade is likely to be a deficiency of large numbers of accurately recorded phenotypes for most productive and adaptive traits and, in particular, for difficult-to-measure adaptive traits such as resistance to disease and environmental stressors.