Ren, W.; Zhao, L.; Yin, H.; Liu, L.

ABSTRACT Objective: This study aimed to systematically analyze the correlation between body weight and body measurement traits and the growth pattern of female Jiangyue donkeys. Methods: A total of 484 female Jiangyue donkeys were selected to determine their body weight (Y) and 11 body measurement traits, including withers height (X1), body length (X2), chest circumference (X3), cannon circumference (X4), head length (X5), neck length (X6), chest width (X7), chest depth (X8), rump height (X9), rump length (X10) and rump width (X11). SPSS 27.0 statistical software was used to conduct descriptive statistics, correlation and regression analysis on body weight and body measurement traits, and the optimal regression equation between them was established by the stepwise method and validated. Furthermore, four growth curve models (Logistic, Gompertz, Brody and Von Bertalanffy) were used to fit the body weight of 241 female Jiangyue donkeys at different months of age. Results: The body weight of female Jiangyue donkeys was significantly positively correlated with all body measurement traits (p<0.01), with the highest correlation coefficient observed for chest circumference. The optimal regression equations for body weight established by stepwise regression yielded R2 values of 0.918 and 0.844 for growing and adult donkeys, respectively (p<0.01). Among the four growth curve models, the Von Bertalanffy model exhibited the best fitting effect (R2=0.99992), with an estimated asymptotic body weight of 184.41 kg, which was close to the measured values of growing female donkeys. Conclusion: The regression models for body weight estimation and the Von Bertalanffy growth curve model for growth pattern evaluation established in this study can serve as effective tools and production management of female Jiangyue donkeys.