近交对内蒙古绒山羊重要经济性状的影响

发布时间：2018-03-18 07:22

本文选题：内蒙古绒山羊　切入点：近交　出处：《内蒙古农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本研究旨在估计内蒙古绒山羊种羊场羊群近交水平及近交对其重要经济性状的影响。试验数据全部采集于内蒙古绒山羊种羊场23年(1990-2012)的系谱和生产性能记录。研究性状包括产绒量、绒长度、绒细度、妊娠期、产羔数、出生重、断奶重、周岁重和成年重。试验运用了两个不同的模型(包含和不包含近交系数)来调查近交对表型值、遗传参数和估计育种值的影响。结果表明,全群平均近交系数为4.01%(0-35.94%),年平均增长率为0.32%。产绒量和绒长度在低水平近交时随着近交增大而增大,但当近交系数分别高于12.5%和4.4%后二者开始下降。然而绒细度却随着近交的增大越来越细。妊娠期和产羔数不受近交影响。对于出生重和成年重,二次与一次效应均显著,回归系数分别为0.0003与-0.0021和0.0116与-0.1557。研究还发现随着近交系数每增加1%,断奶重和周岁重分别显著降低0.0231kg和0.0353kg。此外,对所有性状而言遗传参数和育种值的估计并不会因为模型中引入近交而发生改变。
[Abstract]:The purpose of this study was to estimate the level of sheep inbreeding in Inner Mongolia Cashmere Goat Farm and the influence of inbreeding on its important economic characters. All the data were collected from the pedigree and production performance record of Inner Mongolia Cashmere Goat Farm for 23 years (1990-2012). The traits include cashmere yield, Velvet length, velvet fineness, pregnancy, lambs, birth weight, weaning weight, annual weight and adult weight. Two different models (including and without inbreeding lines) were used to investigate the phenotypic values of inbreeding pairs. The results showed that the average inbreeding coefficient of the whole population was 4.01 ~ 35.94, and the annual average growth rate was 0.32. The yield and length of cashmere increased with the increase of inbreeding at low level. However, when the number of inbred lines was higher than 12.5% and 4.4%, respectively, both of them began to decrease. However, the velvet fineness increased with the increase of inbreeding. The pregnancy and lambs were not affected by inbreeding. For birth weight and adult weight, the secondary and primary effects were significant. The regression coefficients were 0.0003 and -0.0021 and 0.0116 and -0.1557 respectively. It was found that the weaning weight and annual weight decreased by 0.0231 kg and 0.0353 kg respectively with the increase of inbred lines. For all traits, the estimation of genetic parameters and breeding values will not change due to the introduction of inbreeding in the model.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S827

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