Called versus Calculated Yield Grades

An evaluation of carcass data collected over a two year period from southwest Iowa steer tests and 4-H carcass shows was conducted to compare USDA yield grades called by the Federal grader to yield grades calculated by actual carcass measurements. A regression equation was developed to predict called yield grade from carcass measurements. A comparison of the generated equation with the USDA equation used in calculating yield grades suggest that USDA graders accurately predict preliminary yield grades based on fat thickness, but may not have adequate time at line speeds to fully account for adjustments in ribeye size relative to carcass weight.