Sex specific path coefficient and path analysis of body weight and linear body measurements in indigenous Sabi sheep of Zimbabwe
The utility of correlation analysis in the life sciences is considerably enhanced when the correlation coefficient is further analyzed to elucidate the direct influences of one trait on another, as well as the indirect effects mediated by other significant characteristics. This nuanced understanding is particularly vital in selection programs, where identifying key drivers of desirable traits can inform strategic decision-making. Path coefficient analysis is a statistical technique that decomposes correlation coefficients to quantify the direct and indirect relationships between variables, offering a nuanced understanding of the complex interactions within a system. This study employed path coefficient and path analysis to investigate the relationships between body weight and linear body measurements in indigenous Sabi sheep, categorized by sex. A total of 173 sheep (112 ewes, 22 rams, and 39 wethers) were analyzed, focusing on body weight and its correlations with nine linear measurements. Descriptive statistics and path coefficients were calculated to summarize the data. Correlation analysis was also conducted to examine the relationships among variables. The results revealed significant sexual dimorphism in all traits. Notably, body weight (BW) and linear body measurements exhibited small coefficients of variation in ewes while being large in rams and wethers. Correlation analysis showed that all linear traits were positively correlated (p < 0.05) with BW in ewes, rams, and wethers. The correlation ranges between BW and linear body parameters were 0.50-0.90 for rams, 0.45-0.83 for ewes, and 0.37-0.84 in wethers. Specifically, heart girth (HG) had the highest correlation with BW in ewes and wethers, while body length (BL) had the strongest correlation in rams. The results revealed significant direct effects of body length (BL) on body weight in rams, while heart girth (HG) and body length (BL) had the most substantial impacts in ewes. In wethers, heart girth and chest depth were the primary drivers of body weight. Notably, wither height and pin bone width had negative direct effects on body weight in rams, whereas hip width had a negative impact in wethers. No negative direct effects were observed in ewes. This study underscores the importance of body length and heart girth in predicting body weight in indigenous Sabi sheep, providing valuable insights for improving weight estimation, selection, and breeding programs.
Keywords: Body Weight; Linear Body Measurements; Path Analysis; Indigenous Sabi Sheep; Zimbabwe.
