ACCURACY OF ESTIMATES FOR LIVE BODY WEIGHT USING SCHAEFFER’S FORMULA IN NON-DESCRIPT CATTLE (BOS INDICUS), NILI RAVI BUFFALOES (BUBALUS BUBALIS) AND THEIR CALVES USING LINEAR BODY MEASUREMENTS

Abstract

The overall objective of the present study was to devise a method to improve the accuracy of live body weight (BW) estimation using the available information. For this purpose, in the first place 15 non-descript cows, four buffaloes and six calves were weighed on digital weighing platform (observed BW) or their weight was estimated using their morphometric measurements determined by the tape (estimated BW) in two seasons i.e. summer and winter. The data on morphometric measurements were used to predict the BW and subject to simple and multiple linear regression analyses. The relationships between the individual independent variable such as heart girth (HG) with BW were significant (P<0.001) and higher (R2 = 0.65, 0.97 and 0.90 and r = 0.80, 0.98 and 0.95) in all cases for cattle, buffalo and calves, respectively than for diagonal body length (DBL). The multiple linear regression involving more than one independent predictor (e.g. HG and BL) improved this relationship (R2 = 0.67, 0.98 and 0.94, P<0.001) for each of the cattle, buffalo and calves, respectively. In the second place, the association between estimated and observed BW were determined using simple linear regression in order to improve the estimation. The data of this experiment and those of published studies for buffaloes and calves were aggregated. Regression co-efficient of estimated vs. observed BW were 0.88, 0.78 and 0.82 and were highly significant (P<0.001, R2 = 0.68, 0.94, 0.97 and r = 0.83, 0.97 and 0.98) for cattle, buffalo and calves, respectively. The Schaeffer’s formula consistently overestimated live BW for smaller animals while the opposite was true for the heavier animals. HG may be the single best linear measurement for BW prediction for adult cows and buffaloes. Further, the results suggest that the farmers may use the Schaeffer’s formula and equation developed in the present study to estimate live BW with high accuracy for routine farm practices, in the absence of weighing platform.