Impact of dominance effects on sow longevity   总被引：1，自引：0，他引：1  

T. Serenius  K.J. Stalder  & M. Puonti 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2006,123(6):355-361

The purpose of the current study was to estimate variance components, especially dominance genetic variation, for overall leg action, length of productive life and sow stayability until third and fifth parity in the Finnish pig populations. The variance components were estimated in two purebred [Landrace (LR), n = 23 602 and Large White (LW), n =22 984] and crossbred (LR × LW, n = 17 440) data sets. Five different analyses were carried out for all the traits to compare the effect of sows’ inbreeding, common litter environment and parental dominance in the statistical model when determining the genetic correlations of the traits for the two purebred and crossbred populations. Estimated heritabilities for the traits ranged from 0.04 to 0.06. The estimates for the proportion of dominance variance of phenotypic variance (d²) varied between 0.01 and 0.17, and was highest in the crossbred dataset. The genetic correlations of the same traits in purebred and crossbred were all high (>0.75). Based on current results, the effect of dominance should be accounted for in the breeding value estimation of sow longevity, especially when data from crossbred animals are included in the analyses. Because dominance genetic variation for sow longevity exists that variation should be utilized through planned matings in producing sows for commercial production.  相似文献   

Associations between yearling body measurements and career racing performance in Thoroughbred racehorses     

Adriana M. Smith BSc  W. Burton Staniar PhD  Rebecca K. Splan PhD 《Journal of Equine Veterinary Science》2006,26(5):212-214

Yearling morphometric measurements and variables related to career racing performance were collected on 260 Thoroughbreds to determine correlations between and among these traits. Morphometric measurements were adjusted to 365 days based on interpolation from adjacent age points and included wither and hip height, body length, distal limb length, cannon circumference, heartgirth circumference, and chest width. Measures of career racing ability included total earnings, win percentage, and Standard Starts Index (SSI). Wither height and hip height were favorably correlated with lifetime earnings, SSI, and win percentage. Body length and heartgirth were positively correlated with SSI and win percentage. Leg traits were not correlated with any performance parameters. Horses that had placed in or won a stakes race tended to be taller at the wither and hip as yearlings. Horses categorized as preferring turf tended to be taller at the wither and hip at 365 days than those that preferred to run on dirt. No significant difference in yearling morphometric measurements between sprinters and routers was detected. In addition to phenotype and pedigree information, morphometric measurements taken in the yearling year may allow for more accurate estimation of future performance in the Thoroughbred racehorse.  相似文献   

黄羽肉鸡微卫星多态性与料肉比的相关分析     

王曦  李红霞  朱庆 《中国家禽》2007,29(11):22-24

从鸡的遗传图谱中选取13个微卫星基因座,对黄羽肉鸡A系和B系(粤黄鸡102系)回交F1代群体100个个体进行标记与料肉比的最小二乘分析,结果表明:ADL0252、LEI0071、MCW0004、MCW0245、MCW0341这5个基因座与料肉比之间存在着极显著的关系(P<0.01),而基因座MCW0223、MCW0264与料肉比之间存在着显著的关系(P<0.05)。基因座MCW0004的DD型、ADL0252的CC型和MCW0223的AA型所对应的最小二乘均值最大,其有望作为对料肉比性状进行选择的辅助标记。  相似文献   

微孔草的分布及植物群落特征研究   总被引：5，自引：0，他引：5  

王钦  尚可政 《草业科学》1998,15(1):18-26

采用定量样地法,对孔微草这一特种油料植物的群落结构、群落变异以及群落特征进行了研究。结果表明,微孔草干物质生产量占总量的比率,休闲地为９．１６％、撩荒地为１６．９０％、油草地为１５．３２％、燕麦地为１０．６６％、青稞地为５．９７％;群落系数相应为８７．０９％、８７．９１％、９１．８２％、９５．６５％、９３．６０％;优势度相应为９．６０％、１３．４５％、１１．９９％、１６．６１％、７．１３％。经主分  相似文献   

采用两自由度结构的最小拍无纹波控制系统     

张桂香  张建华 《湖南农业大学学报(自然科学版)》1999,26(3)

提出了一种基于两自由度控制器结构的最小拍无纹波控制系统的设计方法。通过有步骤地解两个刁番都方程来直接确定控制器的各个参数。这样所得到的最小拍无纹波控制系统在经过有限拍时间后，可以精确地跟踪预先给定任意函数类的参考输入信号。  相似文献   

黑杨派南方型无性系高生长与气候条件的斜率关联度分析     

余发新  邓晓武 《江西林业科技》2000,(6):9-10,12

用灰色系统理论的斜率关联度分析法，求得影响黑杨派南方型无性系高生长的主要气候因子依次为：降水量、极低温、极高温、蒸发量、日照时数、积温、年均温（或相至湿度）、相以湿度（或年均温）、无霜期。  相似文献   

基因多态性与牛疾病相关性的研究进展     

刘利  黄金明  张嘉保  仲跻峰 《勤云标准版测试》2008,(10)

基因多态性是指基因组序列上的变异,它是决定家畜对疾病易感性与抵抗力、疾病临床表现多样性以及不同个体对药物反应性的重要因素.研究基因多态性有利于定位和鉴定致病基因和疾病易感基因,使得从遗传学的角度控制疾病成为可能,从而达到减少家畜疾病防治的成本,改良家畜品种,为人类提供健康的动物产品的目的.笔者主要从抗病育种的角度综述了近年来基因多态性与牛疾病易感性和抗性的相关研究,并结合遗传信息学和表观遗传学,阐述家畜疾病控制的新进展.  相似文献   

试用关联度分析人才结构的合理性     

孙枫林 《湖南农业大学学报(自然科学版)》2000,27(2)

人才，是经济社会活动诸多要素中最主要，最活跃的要求，结构合理的人才队伍才有可能产生高的效率和效益。本文应用灰关联度分析方法，以通信产业人才队伍为例进行分析，为制定合理的人才队伍结构提供了一种评价方法。  相似文献   

蕴含K1，2，3可图序列的最小度和     

马益聪 《厦门水产学院学报》2009,(1):84-89

经典Turan型问题的变形：确定最小的正偶数σ（H，n），使得对于每一个n项可图序列π=（d1,d2,…,dn）,当σ（π）=d1＋d2＋…＋dn≥σ（H,n）时，π是蕴含N可图的．确定了当n≥6时的σ（K1，2，3，n）。  相似文献   

乳牛产后血浆瘦素动态与亚临床酮病的相关分析     

何宝祥 黄静廖艳娟  杜玉兰韦家周李恭贺  蒋碧桂张宇黄少云  张诗新 《中国兽医科技》2007,37(5):419-424

对某奶牛场16头乳牛产前10d至产后56d血样的瘦素、酮体、葡萄糖、脂肪水平及其动态特征和相关性进行了检测。结果表明，血浆瘦素、血酮、血脂含量在不同乳牛和不同时间点之间均有显著差异。酮体在产后14～49d出现高峰，瘦素和血脂从产后第0d到产后第56d内逐渐升高。瘦素水平与血脂水平呈极显著正相关，血酮与血糖呈极显著负相关。亚临床酮病组乳牛的瘦素和血脂水平分别极显著或显著低于血酮正常组，其瘦素、血酮和血糖在试验期内的波动频率明显减少，跨度变长，瘦素在试验期内仅出现一个两端接近0、波峰不超过1．5ng／mL的波。证实，产后乳牛瘦素、血酮、血糖含量的低频率波动变化和产后8周内血浆瘦素跨时持久的单峰动态变化与乳牛亚临床酮病的发生有关。  相似文献