Correlation and Regression Analysis of the Body Weight and Body Size of Adult Female Yak in Naqu

[Objective] To guide the practical production and breeding of adult female yak in Naqu of Tibet.[Method] According to the measured data of 32 groups of adult female yak in Naqu County of Tibet,the correlation of their body weight with body height,body length,heart girth and cannon circumference was analyzed,and then the regression model for forecasting the weight of adult female yak was established.[Result] The correlation coefficients of the body weight with body height,body length,heart girth and cannon circumference were 0.906,0.612,0.047,0.977;the correlation between body height,cannon circumference and body weight reached the extreme significance level(P0.01),and that between body length and body weight reached significance level(0.01P0.05),while that between heart girth and body weight was not significant(P0.05).Two body weight forecasting regression models were obtained,the correlations between the forecasted value and measured value were 0.989 and 0.977,reaching the extremely significance level at 0.01 level.[Conclusion] The body weight of adult female yak showed obvious linear correlation with its body height,body length,heart girth and cannon circumference.