荷斯坦奶牛外貌性状的主成分分析

Principal component analysis on appearance traits of Holstein cows

随机选取荷斯坦奶牛180头,其中1-3胎各60头,进行奶牛外貌性状体高(x1)、胸宽(x2)、体深(x3)、尻角度(x4)、尻宽(x5)、后肢侧视(x6)、蹄角度(x7)的主成分分析。结果显示,主成分F1~F6的贡献率分别为30.68%、15.67%、14.24%、12.11%、11.18%和9.50%,累计贡献率达93.46%;F1的信息量表达式为F1=0.510 9x1+0.294 6x2+0.448 8x3-0.195 4x4+0.524 3x5-0.012 5x6+0.370 9x7,余类推;F1可视为体躯容积因子,F3、F4可视为耐用因子。主成分(外貌性状的线性组合)可在尽量保持遗传信息的基础上简化复杂的外貌性状间的相关关系。

One hundred eighty Holstein cows at 1 ~ 3 pregnancy were randomly sampled to be measured appearance traits,which including stature（x1）,chest width（x2）,body depth（x3）,rump angle（x4）,rump wedth（x5）,rear leg side view（x6）,and foot angle（x7） for making the principal component analysis on appearance traits of Holstein cows.Results showed that the contribution rates of the principle components F1~ F6 were 30.68%,15.67%,14.24%,12.11%,11.18% and 9.50%,respectively; the accumulative total contribution rate of them was 93.46%.The expression of F1 was F1= 0.510 9x1＋0.294 6 x2＋ 0.448 8x3-0.195 4x4＋0.524 3x5-0.012 5x6＋0.370 9x7,and so on.F1 was regarded as the trunk volume factor,while F3 and F4were regarded as the durable factor.Principal components（the linear combination of appearance traits） could simplify complex correlation between appearance traits on the basis of keeping the genetic information as far as possible.