1. Pork Grading
Pork Evaluation

2. 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

3. 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

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

5. 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

6. 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

7. 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

8. USDA Grade = (4 X Last Rib Backfat) – (Muscle Score)

9. 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 =
(4 X 0.6) – 2 =
For calculations less than 1.0, we will call 1.0

10. 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

11. Percent Fat-free Lean

12. Pork Quality

13. Percent Fat-free Lean
Pounds of fat-free lean (FFL) = (0.465 X HCW) + (3.005 X LEA) – ( 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

14. Percent Fat-free Lean Percent FFL = 51.1 %
Pounds of fat-free lean (FFL) = (0.465 X 200) + (3.005 X 6.0) – ( 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.

15. 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)

16. Wt
LEA FD
% FFL

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