【作者】 赵晓平；

【导师】 荣威恒；

【作者基本信息】 内蒙古农业大学 ， 动物遗传育种与繁殖， 2008， 博士

【摘要】 敖汉细毛羊是根据国家和内蒙古育种计划,以当地蒙古羊为母本、前苏联美利奴羊为父本,经杂交改良、横交固定、自群繁育和导入大约25%的波尔华斯羊和澳洲美利奴羊的血液培育而成的毛肉兼用型品种,1982年正式命名,以毛细、毛长、产毛量高和屠宰率高而著名。为了加快细毛羊的发展,把细毛羊产业做大,2006年敖汉种羊场组建了敖汉细毛羊育种核心群。虽然敖汉细毛羊的选育水平得到了一定的提高,但是缺乏系统的育种理论体系作支撑。本研究在对敖汉细毛羊所处的生产、育种管理体系实际考察之后,确定了现行育种方案中敖汉细毛羊的生物学及育种技术参数、群体经济学以及遗传学参数、群体结构参数、投资参数等。在此基础上,从敖汉细毛羊育种的实际出发,利用系统分析法确定了敖汉细毛羊的育种目标性状,并采用差额法计算了各育种目标性状的边际效益;利用动物模型——最佳线性无偏预测法(BLUP)和多性状非求导约束最大似然法(MTDFREML)对敖汉细毛羊进行了遗传评估,对育种目标性状进行了遗传参数估计;最后以基因流动法为核心,采用ZPLAN软件,将常规育种技术、数量遗传、计算机模拟等理论和计算相结合,对现行的育种方案进行遗传和经济评估,主要得到了以下结论:(1)确定了敖汉细毛羊的3类性状(产毛性状、繁殖性状和生长发育性状)中的6个育种目标性状,分别为净毛量、羊毛细度、羊毛长度、断奶羔羊数、成年母羊剪毛后体重和育成羊剪毛后体重。采用差额法计算了这6个育种目标性状在现有的市场经济和生产条件下的边际效益,依次分别为:成年母羊净毛量32.081、育成羊净毛量30.477、成年母羊毛细度-5.633、育成羊毛细度-5.351、成年母羊毛长度3.010、育成羊毛长度2.860、成年母羊剪毛后体重0.774、育成羊剪毛后体重2.114、断奶羔羊数90.353。通过分析得到3类性状之间的相对经济重要性之比为71.398:17.705:10.898,约为7:2:1,说明敖汉细毛羊的毛用性状经济价值最高。(2)通过运行BLUP和MTDFREML软件对敖汉细毛羊进行了遗传参数估计,计算得出产毛量、毛细度、毛长度、断奶重、周岁重和剪毛后体重的遗传力分别是0.12、0.12、0.16、0.21、0.10、0.12,断奶重的母体加性遗传力为0.03。产毛量与毛长度、断奶重、周岁重和剪毛后体重,剪毛后体重与毛细度、断奶重和周岁重的遗传相关系数分别为0.50、0.20、0.22、0.32,0.05、0.40、0.37,均呈中等遗传正相关;毛细度与产毛量、毛长度、断奶重和周岁重,毛长度和剪毛后体重的遗传相关系数分别为-0.30、-0.40、-0.24、-0.06,-0.01。(3)在对育种目标性状边际效益计算和遗传参数估计的基础上,采用ZPLAN软件对现行育种方案的育种效果进行了评估,结果表明对遗传进展和育种产出的贡献比例公羊组明显要高于母羊组,说明在整个育种过程中种公羊选择非常重要,其选择准确度达到0.84以上,公羊的选择对整个群体的遗传进展、育种效益起着重要作用;在现行育种方案的条件下,每个选择性状的年度遗传进展分别为产毛量0.0629kg、净毛量0.1123kg、细度-0.0768μm、长度0.0401cm、断奶羔羊数0.0009只、周岁重0.3303kg、成母羊体重0.5855kg、断奶体重0.0853kg。平均世代间隔为4.176年。总育种产出为63.198元,其中净毛量48.2007元,细度5.4279元,长度1.6114元,断奶羔羊数0.1999元,周岁重4.8686元,成年母羊体重2.8898元。育种成本为49.766元,育种效益为13.433元,投入产出比为1:1.27。更多还原

【Abstract】 Aohan Merino Sheep variety is used both for wool and meet for which we took local Mongolian sheep as it’s female parent and former Soviet Union Merino Sheep as male parent which was cultivated successfully by hybridization improvement, trans-crossover fix, self-population breeding as well as transduction of 25% percentage blood of Bellhuaz sheep and Australian Merino sheep according to the plan of our nation and Inner Mongolian. The variety was named in 1982 and is famous for its thin wool and wool length. Aohan stud sheep farm begun to construct Aohan Merino Sheep breeding core population to speed up the merino sheep industrial and to develop rapidly and doing it stronger. It is still short of breeding theory system to support it although the work of Aohan Merino Sheep breeding and selection has become stronger. After the practical investigation for production and administration system of Aohan Merino Sheep, the study defined biological and breeding technique parameters, population economics and genetic parameters, population construction parameters, investment parameters and so on .On this basis the economic traits of Aohan Merino Sheep were determined with the methods of systematic analysis and calculated marginal utility of breeding objective traits of Inner Mongolian Aohan Merino Sheep with difference method at the same time . Genetic judge for Aohan Merino Sheep was passed and genetic parameters of breeding objective traits of Merino Sheep were estimated using animal model Best Linear Unbiased Prediction (BLUP) and Multiple Trait Derivative-Free Restricted Maximum Likelihood (MTDFREML). The genetic judge for breeding scheme was done currently in effect taking gene flow method as the core and along with the combining conventional breeding technique, quantitative heredity computer imitation theory with calculation by software ZPLAN. The results were shown as follows:(1) The three types and six breeding objective traits of Aohan merino sheep were determined. The three types of the breeding objective traits were wool traits, reproduction traits and growth traits respectively. The six breeding objective traits were wool yield, wool fineness, wool length, number of kids weaned, weight of adult female sheep after shearing and weight of the young sheep after shearing. The marginal benefit of the three types and six breeding objective traits were calculated by the difference method on the present market and production condition, and the results of wool yield of adult female sheep, wool yield of young sheep, wool fineness of adult female sheep, wool fineness of young sheep, wool length of adult female sheep, wool length of young sheep, weight of adult female sheep after shearing, weight of young sheep after shearing, and the number of kids weaned is 32.081, 30.477, -5.633, -5.351, 3.010, 2.860, 0.774, 2.114, 90.353 respectively. The economic weight proportion of the three type traits is 71.398:17.705:10.898, similar to 7:2:1, which means the wool traits of Aohan Merino sheep have the largest economic value.(2) Estimated genetic parameter of Aohan merino sheep by BLUP and MTDFREML soft wares and the heritability of wool yield, wool fineness, wool length, weaning litter weight, one-age live weight and after shearing weight of adult female sheep is 0.12, 0.12, 0.16, 0.21, 0.10 and 0.12. The maternal additive heritability of weaning litter weight is 0.03. The estimated genetic correlations of wool yield with wool length, weaning litter weight, one-age live weight, after shearing weight of adult female sheep and after shearing weight of adult female sheep with wool fineness, weaning litter weight, one-age live weight is 0.50, 0.20, 0.22, 0.32, 0.05, 0.40, 0.37 respectively. All have a middle level of positive correlation. The estimated genetic correlations of wool fineness with wool yield, wool length, weaning litter weight, one-age live weight and wool length with after shearing weight of adult female sheep is -0.30、-0.40、-0.24、-0.06,-0.01 respectively.(3) Evaluated the breeding effect of the current breeding scheme by the ZPLAN software on the basis of marginal benefit calculated and genetic parameter estimated for the breeding objective traits. The results showed that the contribution proportion for the genetic progress and breeding gain rams higher than ewes groups and the selection of stud rams is very important in the whole breeding process. The selection accuracy is over 0.84 and plays an important role for genetic progress and breeding benefit of the whole population. In the current breeding scheme, the annual genetic progress of wool production, wool yield, wool fineness, wool length, number of kids weaned, one-age live weight, after shearing weight of adult female sheep and weaning litter weight is 0.0629kg, 0.1123kg, -0.0768μm, 0.0401cm, 0.0009, 0.3303kg, 0.5855kg, 0.0853kg respectively. The mean generation interval of the population is 4.176 years and the total breeding gain is 63.198 Yuan. The breeding gain of the wool yield, wool fineness, wool length, number of kids weaned, one-age live weight and after shearing weight of adult female sheep is 48.2007 Yuan, 5.4279 Yuan, 1.6114 Yuan, 0.1999 Yuan, 4.8686 Yuan, 2.8898 Yuan respectively. The breeding cost is 49.766 Yuan, breeding benefit is 13.433 Yuan, and the ratio of input and return for the program is 1:1.27.更多还原