张掖肉牛体重依体尺变化的相关性分析

Correlation Analysis between Body Weight and Body Size of Zhangye Cattle

【目的】为明确肉牛体重因体尺的变化而发生变化的规律和变动范围,为种牛选留和配种前的体况评定和体重估算提供一个参照依据。【方法】以张掖肉牛核心场性能测定的197头12~18月龄的公牛体重和体尺表型值为依据,用SPSS 19.0软件分析体重与体尺间的相关和回归关系,根据相关程度的不同用最小二乘法建立多元线性回归方程,作为制定张掖肉牛种公牛选择标准和对育肥效果进行评估的依据。【结果】张掖肉牛体重与体高、十字高、体斜长、胸围、腹围、管围、睾丸围之间均存在极显著正相关关系(P<0.01)。其中:体斜长(X_(3))、胸围(X_(4))、体高(X_(1))和睾丸围(X7)因相关系数间差异极显著而步进建成最优回归方程Y=-990.152+4.856×X_(3)+2.688×X_(4)+1.701×X_(1)+1.427×X_(7),拟合度(R^(2))达到了0.903(P<0.01),经检验,该方程复相关关系极显著,偏回归系数差异显著,估计的标准差比实测标准差小,具有统计学和实际意义。【结论】可作为舍饲条件下张掖肉牛选留和配种前的体况评定和体重估算的参照依据;在育种实践中,为提高种牛选择质量,继续加强对体重选择的同时,可考虑把体斜长、胸围、体高和睾丸围作为选育性状进行综合评价。

【objective】To clarify the pattern and range of changes in beef cattle weight due to the changes in body size would provide an important method for the selection of bull and the evaluation of fattening effect about Zhangye cattle.【methods】Based on the body weight and body size phenotypes of 197 bulls(12-18 months old),the correlation and regression relationship between body weight and body size were analyzed using SPSS 19.0 software.According to the different degrees of correlation,a multiple linear regression equation was established using the least squares method as a basis for formulating selection criteria for Zhangye beef cattle breeds and evaluating fattening effects.【results】The results showed that there was a highly significant positive correlation between body weight and body height,crossing height,body length,chest circumference,tube circumference and testicular circumference(P<0.01).Among them,the optimal regression equation was established step by step due to significant differences in correlation coefficients between body length,chest circumference,body height and testicular circumference.The fitting degree(R^(2))reached 0.903(P<0.01).After testing,the complex correlation relationship of the equation was extremely significant,and the difference in partial regression coefficients was significant.The estimated standard deviation was smaller than the measured standard deviation,which had statistical and practical significance.【conclusion】It could be used as a reference basis for evaluating the body condition and estimating the body weight of Zhangye cattle under housing condition.In breeding practice,in order to improve the quality of breeding cattle selection and continue to strengthen weight selection,comprehensive evaluation of body length,chest circumference,body height,and testicular circumference could be considered as breeding traits.