Use of body measurements to predict live body weight of Simmental bull in Lembang Artificial Insemination Center, West Java

Abstract

This research aimed to evaluate the use of body measurements (chest girth (CG), body length (BL), and shoulder height (SH)) to predict live body weight (BW) of Simmental bulls in Lembang Artificial Insemination Center, West Java. This research was carried out in December 2019 using a survey method of which all Simmental bulls aged 1—12 years were used in this study. Data were analyzed using simple and multiple correlations and regression models using the R program. Pearson correlation analysis was used to analyze correlation between BW and body measurements, while to find the fittest and more parsimonious regression model we used determination coefficient (R2) and stepwise regression analysis as criteria of selection. The results showed that the average of BW, CG, BL, and SH were 814.54 ± 144.18 kg, 215.72 ± 16.50 cm, 170.13 ± 17.09 cm, and 142.79 ± 11.01 cm, respectively. The results of this study also indicated that CG, BL, and SH positively and significantly correlated with BW, with correlation value of 0.90, 0.85, and 0.79, respectively. Combination of CG, BL, and SH produced the highest correlations value (r = 0.92) with the fittest regression model for predicting BW, namely BW=-888.64 + 4.21*CG + 2.83*BL + 2.20*SH, with R2 of 0.86.