11~14月龄奶水牛体重与体尺指标的相关性分析

本文旨在研究生长期奶水牛体重与体尺指标的相关关系,为通过体尺指标估测其体重提供科学依据。选取76头健康的11~14月龄生长期奶水牛,用地磅、测仗、卷尺分别进行体重与体尺指标测量。采用Excel中LINEST函数对数据进行多元回归和多项式回归分析,用SPSS 17.0对体重与体尺指标进行相关性分析及主成分分析。结果表明,各体尺指标均在不同程度上影响生长期奶水牛的体重,体重与体高、体斜长、十字部高、胸围、腹围、胸宽、胸深、尻长、尻宽和管围均存在极显著相关关系(P<0.01),其中胸围与体重的相关性最大(P=0.823),其次是腹围、体斜长、胸深、管围等;由体重与各体尺指标间多元回归方程的相关系数r可知,11~14月龄奶水牛体重与体尺间存在较强的线性回归关系,可通过不同的体尺指标预测其体重;从主成分的特征根与累计贡献率来看,由第一主成分关系式可见,体重、胸围、体斜长、腹围、管围等的特征向量较大,对第一主成分的贡献也较大,基本反映11~14月龄奶水牛的体型结构,可称为体型因子,第二主成分为尻宽因子,第三主成分为体高因子。

Correlation Analysis between Body Weight and Body Size Indexes of 11-14 Months Old Dairy Buffalo

The paper was to study the correlation between body weight and body size indexes of 11 to 14 months old growing dairy buffalo,which could provide a scientific reference to estimate the weight of dairy buffalo.Seventy six dairy buffalo with the age of 11 to 14 months were selected from the buffalo breeding farm in Guangxi buffalo research institute,body weight and body size indexes were measured according to normal means.Multivariate regression and polynomial regression were analyzed by the function of LINEST in Excel and correlation analysis and principal component analysis were used to analyzed the body weight and body size indexes by SPSS 17.0.The results showed that all the indexes of the body size traits factors affected the buffalo's body weight in different degree.There were extremely significant positive correlation between body weight and body height,body slanting length,high cross height,heart girth,abdominal circumference,chest width,chest depth,rump length,rump width and cannon circumference (P<0.01),in which heart girth was the most relevant (P=0.823),followed by the abdominal circumference,body slanting length,chest depth,cannon circumference and so on.The complex correlation coefficient of multiple regression equations between the body weight and the body size indexes were obtained by polynomial regression,and there was a strong linear relationship between body weight and body size indexes of 11 to 14 months old dairy buffalo,and body size indexes could be used to estimate the body weight of dairy buffalo.From the first principal component with the characteristic roots and the cumulative contribution ratio,we could know body weight,heart girth,body slanting length,abdominal circumference and cannon circumference had a big feature vector,and also had a big contribution to the first principal component,which basically reflected dairy buffalo's body structure of 11 to 14 months old,and this could be called body factor,the second principal component was called rump width factor and the third principal component was called body height factor.