USE OF THE HIP WIDTH TO ESTIMATE THE LIVE WEIGHT IN REPLACEMENT HEIFERS IN THE TROPICS

Abstract

The objective of this study was to evaluate the relationship between the body weight (BW) and the hip width (HW) in replacement heifers bred in the humid tropics. The BW and HW were determined in 200 crossbred heifers. The relationship between the BW and the HW was estimated through regression models. The correlation coefficient between the BW and the HW was 0.97 and the regression equations had a coefficient of determination of 0.95. In this study, the exponential model was the one that presented the best adjustment. The equation was BW (kg)=0.33xHW^1.83 (P=0.0001, r2=0.95, MES=369.29, SRD=19.21 and n=200). The mean error square (MES) varied from 369.29 to 424.14 with standard residual deviations (SRD) (SRD, kg) of 19.21 to 20.59, representing 6.8 % to 7.3 % of the average BW. The HW allows predicting with precision the BW of crossbred heifers kept under conditions of the humid tropics, the prediction error corresponded to 6.8 % of the average BW.