PELVIC MEASUREMENTS IN BEEF REPLACEMENT HEIFERS AND BULLS

Pelvic measurements of heifers and bulls has been evaluated as a means of predicting dystocia and selecting breeding stock. Two problems com plicate the interpretation of the data. First, pelvic dimensions must be measured accurately. The measurement device must be correctly calib rated, and the measurement must be taken with reference to the skeleta l landmarks. Small errors in measurement can yield large differences i n pelvic area. Second, heifer size and calf birth weight vary accordin g to climate and management factors. Ratios of calf birth weight to pe lvic area should therefore be calculated to fit the specific herd and management. If these caveats are observed, pelvic measurement (along w ith selection of sires for low birth-weight estimated progeny differen ces) will help reduce the incidence of dystocia in beef cattle.