Lamb yield grade is rated on a scale of 1 through 5, with 1 being the highest yield. Which measurement is used in this grading?

• A. 0.4 times 10 times fat thickness
• B. 1.0 times fat thickness
• C. 0.5 times weight
• D. 2.0 times fat thickness

Answer: (A)

Fat thickness measured at the loin is the measurement used to assign lamb yield grade. The grading formula combines that thickness with a fixed base: yield grade equals 0.4 plus ten times the fat thickness in inches. This setup links how much fat cover the carcass has to the yield—the smaller the fat thickness, the lower the yield grade (closer to 1), and the fatter the carcass, the higher the grade (toward 5).

For example, if fat thickness is 0.2 inches, the yield grade is 0.4 + (10 × 0.2) = 2.4, which aligns with the 1–5 scale. Another choice would rely on weight or a different multiplier, which isn’t how lamb yield grade is determined.