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

Abstract
Structural measurements are indicators of animal performance, productivity and carcass characteristics. This study was conducted with the objectives of assessing structural measurements, developing body weight prediction and structural indices for cows of Arsi breed. The cows were purchased from highland and lowland agro-ecologies of Arsi and East Shoa zones of Oromia regional state, Ethiopia and kept in Adami Tulu Agricultural Research Center (ATARC) for the breed development purpose. Totally 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 observational survey. The structural index was calculated from the phenotypically correlated linear measurements. Structural traits were analyzed by T-test of SPSS version twenty four. 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 body weight of the cows. Regression analysis indicated that hearth girth had the highest coefficient of determination for body weight of the cows and heifers. Accordingly, the simple linear equations were developed to predict the body weight of cows and heifers. Body weight of Arsi cow (y) = -221.005 + 3.1(heart girth) and Body weight of 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.