【摘要】 本文在文献的基础上,应用主成分分析和聚类分析法,对中国黑白花奶牛引种改良的问题进行分析和总结。结果认为,中国黑白花奶牛与日本黑白花、德国黑白花和丹麦黑白花奶牛比较接近,与美国黑白花奶牛差异较大。用美国黑白花奶牛提高中国黑白花奶牛的乳用性能比较理想。此外,还发现杂交1代所具有的性能表现更接近母亲品种,具有母体效应。更多还原

【Abstract】 Studies were made on the changes of Chinese Black and White (CBW) improved by imported Holstein sires and semen from US, Japan, Germanr and Denmark, using principal component analysis and clustering analysis on the basis of reference〔 1 〕. Results indicate that the distance between CBW and Japanese Black and White is the smallest, and US Holstein the longest.To improve dairyness of CBW, it is recommended the importation of US genes. Maternal effect is found in the first filial generation in this analysis too.更多还原