The study pertains to assessment of body weight of Boran bulls reared at two feedlots of Southern Ethiopia. Boran cattle are raised by the pastoralists under extensive management system and the region lacks even the basic restraining chutes and weighing balances. Thus, the study was conducted to predict the body weight of the bulls reared in two locations of Southern Ethiopia using linear body measurements of bulls aged 2 and 3 years of age and to predict the body weight at 3 and 4 years of age and 4 years of age respectively using linear and some curvefit regression equations. The study was conducted at two locations the first location was devoid of any wind breaks and was bitterly cold in the night which was uncomfortable for the bulls while the second location had well built infrastructures and hence was quite comfortable for the bulls. The results indicated that the morphometical traits and body weight varied across the two locations, indicating a significant genotype by environment interactions for the traits. The findings also indicated that the predictors for assessing the body weight varied according to the age and location. The rump length of the bulls reared at the first location and aged 2 years was significantly correlated with their body weight , while for the bulls aged 3 and 4 years respectively years and reared in the first location the traits significantly correlated with body weight were the heart girth and flank width respectively. While body depth and heart girth respectively were the traits which were significantly correlated with the body weight of the bulls aged 3 and 4 years respectively. The results also indicated that the height at withers and heart girth of the bulls aged 3 years and reared in the first and second locations were best predictors for assessing the body weight of the bulls aged 4 years and in the respective locations. The results also indicated that among the regression equations the accuracy was higher using quadratic regression equations among the bulls across all the age groups. However, the body weight of the bulls aged 3 years and reared at the second location was best assessed using exponential and power regression. 1479801685.php