【作者】 任红艳；

【导师】 许尚忠；

【作者基本信息】 中国农业科学院 ， 动物遗传育种与繁殖， 2001， 硕士

【摘要】 本研究采用7个国家级种畜场1980～2000年间的数据对中国西门塔尔牛21年来的育种效果进行分析。除计算主要性状的遗传参数外，还对其育种值进行估计，并分析变化趋势；所有性状均采用动物模型并利用MT—DFREML（多性状非求导REML）软件进行分析。所分析的性状有：305天产奶量、乳脂率、乳蛋白率、18月龄体重、18月龄日增重以及体型评分，其各自的遗传力分别为0.35、0.2、0.21、0.31、0.29、0.18；近交系数在0～0.013之间；产奶量群体平均育种值呈上升趋势，乳脂率变化并不大，体重和体型评分则呈下降趋势。 结果表明，采用开放核心群育种体系能有效控制群体近交系数。同时，经过20多年的选育，中国西门塔尔牛在乳用性能上有较大程度的提高，且乳脂率也能保持在3.7％左右。在今后的育种过程中，在保证较高乳用性能的同时，还要加强对肉用性能的选择，以突出中国西门塔尔牛乳肉兼用的品种特性。更多还原

【Abstract】 Datacontalning l8495 records of 7928 bomals) of ChineseSinunental were collected from 7 livestock breeding bos at nationallevel to evalwte the breeding effect of Chinse Shaental over 20years. Besides evalwting the genetic paramaters, we also evaluate thePBV(Predicted Breeding Value) of the four main traitS and analysistheir trends. Inbreeding coefficients were also analyZed in this studyThe traits anaiyzed were 305-day milk yteld, ndlk fat percentage, milkprotein percentage, body weigh at l8 months, chly gain at l8 monthsand score of body tyPe. Their heritabilities are 0.35, 0.2, 0.2l, 0.3l,0.29 and 0. 18 resPectively The mean PBV of 305-day Inilk yield keptgoing uP, ndlk fat percentage has no obvious fluchation, body weighand body tyPe score Presellted a going down trCnd.The resultS indicate that. it can cofibol the coefficient of inbreedingeffechvely using ONBS and a lot of propess have been made onChinse Striental ndlk yield trait, and tha, the ndlk fat percentage isabout 3.7%. More attention should be paid to body weight of ChineseSinunental, improving the meat performance as well as ndth yteldperformance in the fufor.更多还原