西北地区湖羊6月龄体重与体尺的多元回归分析

Multiple regression analysis of body weight and body size of 6-month-old Hu sheep in Northwest China

为了探究西北地区湖羊体重与体尺的相关关系,试验采用相关性分析、通径分析、多元回归分析和逐步回归分析,利用SPSS 19.0软件对848只湖羊的体重(Y)和体高(X_(1))、体斜长(X_(2))、胸围(X_(3))、管围(X_(4))、胸深(X_(5))、胸宽(X_(6))、十字部高(X_(7))、腰角宽(X8)8个体尺指标进行生长发育规律和相关性研究,构建体重对体尺性状的最优回归模型。结果表明:湖羊6月龄各项体尺指标与体重呈极显著正相关(P<0.01),胸围、管围、十字部高、腰角宽4个体尺指标是影响湖羊体重的主要因素,其中胸围对公羊和母羊的体重直接影响作用最大(直接作用系数分别为0.481和0.355),腰角宽对公羊和母羊体重的间接作用最大(间接作用系数分别为0.653和0.528);通过多元回归分析构建的公羊和母羊体重对体尺性状的最优回归方程模型分别为Y=0.117X_(2)+0.494X_(3)+0.301X_(4)+0.135X_(6)+0.138X_(7)-79.750(R^(2)=0.884,P<0.05)和Y=0.367X_(3)+0.176X_(4)+0.240X_(5)+0.076X_(6)+0.271X_(7)-65.478(R^(2)=0.746,P<0.05)。说明在今后湖羊选育工作中应优先重点考虑胸围、管围、十字部高和腰角宽,加大对其的选择力度,同时综合考虑其余体尺性状对体重的影响,满足肉羊选育工作要求。

In order to investigate the correlation between body weight and body size of Hu sheep in Northwest China,SPSS 19.0 software was used to study the growth and development rules and correlation by correlation analysis,path analysis and multiple regression analysis of 848 Hu sheep's body weight(Y)and 8 body size indexes including body height(X_(1)),body length(X_(2)),chest circumference(X_(3)),tube circumference(X_(4)),chest depth(X_(5)),chest width(X_(6)),cross height(X_(7))and waist angle width(X_8),and the optimal regression model of body weight and body size traits was established.The results showed that there was a significant positive correlation between body size index and body weight of 6-month-old Hu sheep(P<0.01).Chest circumference,tube circumference,cross height and waist angle width were the main factors affecting body weight of Hu sheep,among which chest circumference had the greatest direct effect on body weight of rams and ewes(correlation coefficients were 0.481 and 0.355,respectively),and the indirect effect of waist angle width on body weight of rams and ewes was the largest(correlation coefficients were 0.653 and 0.528,respectively).Through multiple regression analysis,the optimal regression equation model of body weight on body size traits of male and female sheep were Y=0.117X_(2)+0.494X_(3)+0.301X_(4)+0.138X_(7)-79.75(R^(2)=0.884,P<0.05)and Y=0.367X_(3)+0.176X_(4)+0.24X_(5)+0.076X_(6)+0.271X_(7)-65.478(R^(2)=0.746,P<0.05).The results indicated that chest circumference,pipe circumference,hip height and waist angle width should be given priority in the future breeding of Hu sheep,and the selection of them should be strengthened.Meanwhile,the influence of other body size traits on body weight should be comprehensively considered,so as to meet the requirements of breeding work of mutton sheep.