荷斯坦奶牛产奶量与乳成分的相关性研究

Correlation between Milk Yield and Milk Composition of Holstein Cows

为探讨湖北地区荷斯坦奶牛产奶量、乳成分的相关性,本研究选择2016年湖北省3个牧场的DHI数据,运用SPSS17.0中的双变量相关分析和偏相关分析,分析产奶量与乳成分的相互关系。结果表明:3个牧场产奶量与乳脂率、乳蛋白率、体细胞数、乳尿素氮呈负相关(P<0.01);乳脂率与乳蛋白率、体细胞数、乳尿素氮均呈正相关(P<0.01);乳蛋白率与体细胞数呈正相关(P<0.01),与乳尿素氮呈负相关(P<0.01);体细胞数与乳尿素氮均呈负相关(P<0.01);产奶量与体细胞数简单相关系数-0.003(P>0.05),偏相关系数-0.054(P<0.01);体细胞数与乳尿素氮含量简单相关系数0.003(P>0.05),偏相关系数-0.134(P<0.01)。在产奶量与乳成分间关系研究中简单相关分析与偏相关分析结果不一致,在多个变量相关性研究中,偏相关分析更能真实反映2个变量间本质联系。

In order to discuss the relationship between milk yield and milk composition of Holstein cows in Hubei province,in this study, the DHI data of 3 farms in Hubei province in 2016 were selected, and the correlations between milk yield and milk components were analyzed by using bivariate correlation analysis and partial correlation analysis in SPSS 17.0. Results showed that milk yield was negatively correlated with milk fat percentage, milk protein ratio, somatic cell count and milk urea nitrogen in the 3 pastures （P〈0.01）; Milk fat percentage was positively correlated with milk protein ratio, somatic cell count and milk urea nitrogen （P〈0.01）; Milk protein ratio was positive correlation with somatic cell count （P〈0.01） and negatively correlated with milk urea nitrogen （P〈0.01）; There was negative correlation between somatic cell count and milk urea nitrogen （P〈0.01）; The simple correlation coefficient between milk yield and body cell number was -0.003 （P〉0.05）, and the partial correlation coefficient was -0.054 （P〈0.01）;The simple correlation coefficient between somatic cell count and milk urea nitrogen content was 0.003 （P〉0.05）, and the partial correlation coefficient was -0.134 （P〈0.01）. The results of simple correlation analysis and partial correlation analysis between milk yield and milk composition are inconsistent. In the study of correlation of multiple variables, partial correlation analysis can reflect the essential relationship between the two variables.