Abstract:

[Objective] This study was conducted to analyze the correlation between body weight and body size indexes of Sunit sheep, a local distinctive mutton sheep breed in Xilin Gol League of Inner Mongolia, China. [Method] A total of 247 Sunit rams and a total of 260 Sunit ewes aged 5 to 6 months with good development and health condition were randomly selected, and the indexes potentially associated with production performance including body weight （Y）, tail length （X₁）, tail width （X₂）, body height （X₃）, body length （X₄） and chest circumference （X₅） were measured. Following data processing, SPSS 26.0 software was used to perform correlation analysis and multiple linear regression analysis on the body weight and body size indexes. The best regression model was then established. [Result] The main body size indexes affecting the body weights of Sunit rams and ewes were tail width, body height, body length and chest circumference, which were all extremely significantly （P<0.01） correlated with the body weight. A multiple linear regression model was established by stepwise regression analysis. The optimal linear equation of Sunit ram was: Y=0.57X₅+0.325X₄+0.241X₂-35.795, R²=0.834; the optimal linear equation of Sunit ewe was: Y=0.577X₅+0.246X₄+0.205X₂-31.94, R²=0.799. [Conclusion] The body size indexes of chest circumference, body length and tail width had high correlation with body weight in the regression equation, and all of them could be used as the prediction indicators for body weight.

Key words: Sunit sheep, body weight, body size, correlation analysis, model