张掖肉牛体重依体尺变化的相关性分析

Regression Analysis between Body Weight and Body Size of zhangye Cattle

中文关键词: 张掖肉牛；生长性状；相关分析；通径和回归分析  种牛选择

英文关键词: zhangye cattle  growth character  analysis of correlation , path analysis and regressive,Breeding cattle selection

中文摘要:

      【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（）、胸围（）、体高（）和睾丸围（）因相关系数间差异极显著而步进建成最优回归方程，拟合度（R2）达到了0.903（P＜0.01），经检验该方程估计的标准差比实测标准差小，具有统计学意义。【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[1]，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。

英文摘要:

      【objective】 In order to provide an important method for the selection of bull and the evaluation of fattening effect about zhangye cattle,the correlation between body weight and body size of cattle was analyzed,the direct effects and indirect effects of body size on body weight were clarified，and the linear regression relationship between body weight and body size was studied.【methods】]197bull（12-18 months old）were selected as the study subjects in the experiment.The body weight and body size were measured，and the measurement results were analyzed by SPSS 19.0 software for correlation，path and stepwise regression analysis，and the optimal linear regression equation was established.【results】The results showed that the body height,body length,chest circumference,tube circumference,testicular circumference and height were significantly positively correlated with body weight（P＜0.01）,the most direct effect on body weight was chest circumference,the optimal regression equation between body weight and body size index of zhangye cattle was . 【conclusion】The results indicated that this equation has statistical significance and can be used to estimate the body weight of zhangye cattle under housing condition. Not only body weight selection should be taken into account，but also to the selection of body length,chest circumference,tube circumference ,the testicular circumference and height .