用最小二乘法原理估测黄牛体重

应用最小二乘法原理选用黄牛的体长、胸围两项体尺 ,来估测黄牛的体重 ,不同的估测方法其估测的精度不同。采用体长和胸围两项体尺建立的二元二次回归方程估测的体重Y1 与实测的体重Y0 的相关系数最高 (r0 1 =0 .670 5 ) ,其次为用体长X1 和胸围X2 建立二元一次回归方程估测的体重Y4与实测的体重Y0 的相关系数 (r0 4=0 .63 62 ) ;用胸围X2 的单项体尺估测的体重Y3与实测体重Y0 的相关系数r0 3为 0 .62 6;用体长X1 的单项体尺估测的体重Y2 与实际体重Y0 相关系数最小 ,r0 1 、r0 2 、r0 3、r0 4均达到极显著水准。体长和胸围这两项单项体尺对估测体重的重要性不同 ,胸围对体重的贡献率较体长为大

Estimate of the Weight of Cattle and Application of the Least Square Method

The Least Square Method was applied to estimate a cattle's weight according to its body length and chest girth. Different estimative method was different in accuracy. The correlation coefficient of real weight Y 0 and estimated weight Y 1 based on regression equation established by body length and square of chest girth was r 01 =0.670 5. And that of Y 0 and estimated weight Y 2 by regression equation established by body length X 1 was r 02 =0.614. And that of Y 0 and estimated weight Y 3 by regression equation established by chest girth X 2 was r 03 =0.626. And that of Y 0 and estimated weight Y 4 by regression equation established by body length X 1 and chest girth X 2 was r 04 =0.6362. All of r 01 、 r 02 、r 03 、r 04 had extremely significant difference.Estimating weight by body length and by chest girth had different importance. The influence of body length was greater than that of chest girth on the accuracy of estimating weight.