Structural Traits, Structural Indices and Body Weight Prediction of Arsi Cows

Structural measurements are indictors of animal performance, productivity and carcass characteristics. This study was conducted with the objectives of assessing structural measurements, developing body weight predictions, and developing structural indices for cows of the Arsi breed. The cows were purchased from the highland and lowland agro-ecologies of the Arsi and East Shoa zones of Oromia and kept in the Adami Tulu Agricultural Research Center (ATARC) for breeding purposes. A total of 222 cows were included in the structural traits measurement. Thirty-four young heifers were also considered in the study. Twenty-two structural traits were considered during the observational survey. The structural index was calculated from the phenotypically correlated linear measurements. The observed average values of height at wither, chest depth, heart girth, body length, pelvic width, cannon bone circumferences of the cows were 107, 55.62, 141.06, 117.82, 31.41 and 13.58cm, respectively. Heart girth (0.82), flank girth (0.73), hook circumferences (0.67), chest depth (0.65) and height at rump (0.64) were highly correlated (P< 0.01) to the body weight of the cows. Regression analysis indicated that hearth girth had the highest coefficient of determination for the body weight of the cows and heifers. Accordingly, the simple linear equations were developed to predict the body weight of cows and heifers. The body weight of an Arsi cow (y)=-221.005 + 3.1 (heart girth) and the body weight of an Arsi heifer (y) =-188.452 + 2.75 (heart girth). Based on this, the measuring chart tape can be developed to estimate the body weight of Arsi cows and heifers at field condition where there is no access to weighing scales.