Pork Grading Pork Evaluation

Sex Classes Eligible USDA Grades Barrow - U.S. No. 1-4, U.S. Utility Gilt - U.S. No. 1-4, U.S. Utility Sow - U.S. No. 1-4, U.S. Utility Stag - None Boar - None

Classes of Pork Carcasses Barrow Pizzle eye Small triangular exposed lean (gracillis / semimembranosus) Rough navel edge (sheath pocket) Gilt No pizzle eye Larger bean-shaped exposed lean (gracillis / semimembranosus) Smooth navel edge

Gilt Barrow Pizzle eye No Pizzle eye Small triangle Large Bean Rough Smooth Barrow Gilt

Classes of Pork Carcasses Sow Gilt traits Mammary tissue development Heavier carcasses Boars and Stags Pronounced male traits (pizzle eye) Heavy muscled shoulders Large bones and joints Darker lean Heavier carcasses

USDA Pork Grades Predicts the percentage of the four, bone-in, closely trimmed lean cuts (ham, loin, Boston butt, and picnic shoulder U.S. No. 1 – 60.4 % or greater U.S. No. 2 – 57.4 to 60.3 % U.S. No. 3 – 54.4 to 57.3 % U.S. No. 4 – less than 54.4 % U.S. Utility – Carcasses with unacceptable quality

Carcasses must have minimal quality to grade U.S. 1 - 4 At least slightly firm lean and fat Grayish-pink to moderately dark red color of lean At least slight feathering Minimum of 0.6 inch of belly thickness

USDA Grade = (4 X Last Rib Backfat) – (Muscle Score) 3 2 1

Thin muscled carcasses cannot grade U.S. No. 1 (4 X LRBF) – (MS) = USDA Grade (4 X 0.9) – 2 = 1.6 (4 X 0.5) – 1 = 1.0 2.0 (4 X 0.6) – 2 = 0.4 1.0 For calculations less than 1.0, we will call 1.0

Percent Fat-free Lean Predicts the percentage of carcass consisting of acceptable quality lean with all fat (including marbling) removed Must have at least slightly firm lean, slight marbling, and grayish-pink to moderately dark red color

Percent Fat-free Lean

Pork Quality

Percent Fat-free Lean Pounds of fat-free lean (FFL) = 8.588 + (0.465 X HCW) + (3.005 X LEA) – (21.896 X FD) HCW = Hot Carcass Weight, skin on LEA = Loin eye area between 10th/11th rib FD = Fat depth at 10th/11th rib including skin, ¾ up the loin eye muscle Percent FFL = (lbs. FFL / HCW) X 100

Percent Fat-free Lean Percent FFL = 51.1 % Pounds of fat-free lean (FFL) = 8.588 + (0.465 X 200) + (3.005 X 6.0) – (21.896 X 0.8) Percent FFL = (102.1 / 200) X 100 Percent FFL = 51.1 % HCW = 200 lb. LEA = 6.0 in2 FD = 0.8 in.

Percent Fat Free Lean For evaluation purposes: Approximately 0.5 (0.4567) in2 of Loin eye area (LEA) compensates for 0.1 inch of fat depth (FD)

Wt. 180 170 221 LEA 7.5 4.0 6.0 FD 0.8 0.6 1.3 % FFL 54.1 50.9 45.7

Pork Evaluation Ribbed Pork Carcasses Unribbed Pork Carcasses Hams Loins (IMPS 412) Pork Chops