Abstract:
Impact of research findings on Tanzania shorthorn zebu (TSHZ) cattle under agropastoral
system in Tanzania have been lessened due to difficulties in relating visual appearance of animals with their live body weights. Managerial decisions have therefore been based on rough and inaccurate estimates. A simple, workable and accurate means was therefore thought to predict live weight of zebu cattle using heart girth measurement. A total of 300 TSHZ cattle were subjected to weighbridge as well as heart girth measurements and the findings subjected to regression analysis. Their live weights ranged from 170 to 390 Kg.
The study revealed that heart girth had high correlation coefficient with live weight (r = 0.94, p<0.01). Grouping of data according to sex indicated that heart girth and live weight had closest correlation coefficient in both male and female, r = 0.9385 and r = 0.9318, respectively. The regression analysis of live weight on heart girth was highly significant (R² = 0.88, P<0.01), and the regression lines indicated that a linear relationship existed. The general equation for prediction of live weight of the TSHZ cattle was as follows: Y = 4.55 X – 409 (± 17.9), Where, Y = live weight (Kg), X = heart girth (cm). This implies that the use of the heart girth measurements in prediction of live weight of TSHZ cattle is credible.
