1. U.S. Quality Grades
Sex Class
Maturity
Marbling
Firmness

2. Purpose of Grading Facilitate the marketing of meat
To sort carcasses from a heterogeneous population into homogeneous groups

3. Sex Class Determination Steer vs Heifer
Trait
Steer
Heifer
Pizzle eye
Present
Absent
Semimembranosus
Square shaped
Bean shaped
Secondary sex fat depot
Rough, grape-like
Smooth in appearance

4. USDA Beef Quality Grades
Quality grades are an estimate of beef palatability

5. Beef Palatability
Tenderness
Juiciness
Flavor

6. USDA Quality Grades Grades of Youthful Carcasses (< 42 mos.)
Prime
Choice
Select
Standard
Grades of Mature Carcasses (> 42 mos.)
Commercial
Utility
Cutter
Canner

7. USDA Quality Grades Based on consideration of two general factors:
Physiological Maturity
Skeletal Maturity
Lean Maturity
Marbling (Intramuscular Fat)
Amount
Distribution

8. USDA Beef Grades Maturity Scores: Marbling scores: (Highest to lowest)
USDA maturity and marbling scores
Marbling scores: (Highest to lowest)
-Abundant
-Moderately Abundant
-Slightly Abundant
-Moderate
-Modest
-Small
-Slight
-Practically Devoid
-Devoid
Maturity Scores:
A Youngest B C D
E Oldest

9. Relationship between tenderness and USDA maturity scores

10. Physiological Maturity vs Chronological Maturity
The physiological maturity of the carcass is an estimate of the actual chronological age of the animal
USDA Maturity Score Estimated chronological age
A to 30 months
B to 42 months
C to 72 months
D to 96 months
E or more months

11. Physiological Maturity
Skeletal Maturity is determined by evaluating the condition of the cartilage in the vertebral column, with heavy emphasis placed on the cartilaginous buttons at the end of the thoracic vertebra
Lean maturity is determined by the color and firmness of the ribeye at the 12th 13th rib interface

12. Beef Skeletal Maturity
C00 35% 42 – 72
D00 70% 72 – 96
E00 90%
E %
% Thoracic
Ossification
Approximate
Age (Months)
> 96
Skeletal Maturity:
A00
B00
C00
D00
E00

13. Beef Skeletal Maturity
Physiological Skeletal Ossification is only marginally related to chronological age of the live animal.

14. “A” and “B” Maturity Carcass Thoracic Chine Buttons
“A” Maturity
“B” Maturity

15. A B C D E
SACRAL
DISTINCT
SEPARATION
LUMBAR NO
OSSIFICATION
THORAIC

19. Physiological Maturity of Lumbar Vertebrae of from carcasses with A40 and A50 Overall Maturity Scores
A40
A50

20. A B C D E SACRAL LUMBAR THORAIC DISTINCT SEPARATION FUSED NO
OSSIFICATION
NEARLY
COMPLETELY
OSSIFIED
THORAIC
SOME
PARTIAL
CONSID.
OSS.
OUTLINES
PLAINLY
VISIBLE
BARELY

21. A B C D E RIBS TEXTURE COLOR OF LEAN LIGHT RED SLIGHT TENDENCY TOWARDS
FLATNESS
SLIGHTLY
WIDE
AND
FLAT
TEXTURE
FINE
TENDS TO
BE FINE
SLIGHTLY COARSE
MOD.
COARSE
COLOR OF LEAN
LIGHT RED
DARK
RED

22. Skeletal Maturity A B C D E Sacral Lumbar Thoracic*
Distinct separation
Some separation
Fused
Lumbar
No ossification
Partial ossification
Mostly ossified
Ossified
Thoracic*
0-10%
10-35%
35-70%
70-90%
90% +
*Average ossification of first three thoracic vertebra

24. Spinous process of the Thoracic vertebra
“Buttons”
Thoracic vertebra

25. Beef Quality Grades- Lean Maturity
Young
Intermediate
Mature
A00
B00
C00
D00
E00

26. Various Maturity of Beef Cattle
A-Maturity
C-Maturity
D-Maturity

27. Overall USDA Maturity
A-Maturity

28. Overall USDA Maturity Combine Skeletal & Lean Average
If within 40 degrees- simple average
> 40 degrees- average the degrees then adjust 10 degrees toward bone
If average of Skeletal & Lean crosses C/B line, & skeletal is C- it stays with the skeletal side
Overall maturity cannot differ more than 1 full maturity from skeletal

29. USDA Quality-Marbling
Marbling, or intramuscular fat flecks within the exposed ribeye area
Usually the major factor determining quality grade
Flecks of fat within the encircled area

30. Marbling Slight00 Small00 Modest00 Moderate00 Slightly Abundant00
Moderately Abundant00

31. USDA Quality Grades

32. Quality Grade

33. Overall USDA Maturity Determining Final Quality Grade
A maturity overall- Marbling determines Quality grade
It takes a greater amount of marbling to compensate for added maturity to receive same Quality grade
Overall maturity should be adjusted back to respective Maturity 00 also creating an adjusted marbling score

34. Overall USDA Maturity Determining Final Quality Grade
Special rule B maturity overall with SM or SL marbling = High Std
Everything else adjusted back to respective Maturity 00 C D E MD
SLAB
MAB MT SM SL TR PD

35. USDA Yield Grades

36. Beef Yield Grades
USDA Yield Grades predict the percentage of carcass weight in boneless, closely trimmed retail cuts from the round, loin, rib and chuck
Lean : Fat + Bone

37. USDA Yield Grades
Yield/Cutability estimates are determined using four criteria
Hot Carcass Weight, lbs
Adjusted Fat Thickness, in.
Ribeye Area, in2
% KPH

38. History
USDA developed the cutability equation but it was not used because it was hard to sort carcasses based on percentage cutability.
So, they developed the equation to estimate yield grade and used those grades (1,2,3,4,5) to sort carcasses

39. USDA Yield Grade USDA YG %BCTRC 1 2 3 4 5 52.3 % or More 52.3 - 50.0%
51.34 – 5.784(Adj.Fat) – 0.462(KPH) (REA) – (HCW)
USDA YG =
(Adj.Fat) + 0.2(KPH) (REA) (HCW)
USDA YG %BCTRC 1 2 3 4 5
52.3 % or More % % %
45.4% or Less

40. USDA Yield Grade First-
We Will Use the 3-Step Short-Cut Method to determine USDA Yield Grade
4 parameters utilized in beef yield grades
HCW
REA
Adj. Fat Thickness
% KPH

41. USDA Yield Grade Step 1- Determine Preliminary YG (PYG)
Fat Thickness
PYG
0.0
2.0
0.1
2.25
0.2
2.5
0.3
2.75
0.4
3.0
0.5
3.25
0.6
3.5
0.7
3.75
0.8
4.0
0.9
4.25
1.0
4.5
1.1
4.75
1.2
5.0
Step 1- Determine Preliminary YG (PYG)
PYG= YG for every 0.1” of fat
NOTE: Report all PYG to the nearest tenth of a PYG- round up
Example- 0.3”= PYG- 2.75
2.75= 2.8

42. USDA Yield Grade
Carcass Wt
Req. REA
550
10.4
575
10.7
600
11.0
625
11.3
650
11.6
675
11.9
700
12.3
725
12.5
750
12.8
775
13.1
800
13.4
825
13.7
850
14.0
875
14.3
900
14.6
925
14.9
950
15.2
Step 2- Determine Ribeye (REA) adjustment/ Hot Carcass Wt (HCW)
IF INBETWEEN WTS- USE Rule
EXAMPLE- 608 lbs needs 11.0; 609 lbs needs 11.1
616 lbs needs 11.1; 617 lbs needs 11.2

43. USDA Yield Grade
Carcass Wt
Req. REA
550
10.4
575
10.7
600
11.0
625
11.3
650
11.6
675
11.9
700
12.3
725
12.5
750
12.8
775
13.1
800
13.4
825
13.7
850
14.0
875
14.3
900
14.6
925
14.9
950
15.2
Step 2- Continued- Determine Ribeye (REA) adjustment/ Hot Carcass Wt (HCW)
Req. REA- Actual REA =Adj. Factor 3
ONLY Tenths of a YG Adjustment
Actual > Req. = Subtract Adj Factor
Req. > Actual= Add Adj Factor

44. USDA Yield Grade Step 2- Example 717 lb carcass needs 12.4 in REA
Carcass Wt
Req. REA
550
10.4
575
10.7
600
11.0
625
11.3
650
11.6
675
11.9
700
12.3
725
12.5
750
12.8
775
13.1
800
13.4
825
13.7
850
14.0
875
14.3
900
14.6
925
14.9
950
15.2
Step 2- Example
717 lb carcass needs 12.4 in REA
Actual REA- 15.3
12.4 – 15.3 = .966 3
Adj Factor= -1.0

45. USDA Yield Grade Step 3- % Kidney, Pelvic and Heart Fat
% KPH
YG ADJ
5.0
+.3
4.5
+.2
4.0
+.1
3.5
0.0
3.0
-.1
2.5
-.2
2.0
-.3
1.5
-.4
1.0
-.5
0.5
-.6
Step 3- % Kidney, Pelvic and Heart Fat
Base = 3.5% +/- .5%= +/- 0.1 YG

46. USDA Yield Grade Calculation
Fat thickness = 0.5 in PYG=3.25 ≈ 3.3
HCW = 750 lb- Req. REA- 12.8
Actual REA- 14.1
12.8 – 14.1 = = Adj Factor= -.4 3
2.5% KPH= -.2
Final YG= 2.7
For this class, all yield grades are calculated to the nearest 0.1 yield grade (range: ) with no rounding

47. USDA Yield Grade
Next-
We Will Use the 4-Step Method to determine USDA Yield Grade
Again, 4 parameters utilized in beef yield grades
HCW
REA
Adj. Fat Thickness
% KPH
-Main difference between 3 and 4-step method is in the 4-step method HCW and REA are not combined, accounting for the extra step.

48. USDA Yield Grade Step 1- Determine Preliminary YG (PYG)
Fat Thickness
PYG
0.0
2.0
0.1
2.25
0.2
2.5
0.3
2.75
0.4
3.0
0.5
3.25
0.6
3.5
0.7
3.75
0.8
4.0
0.9
4.25
1.0
4.5
1.1
4.75
1.2
5.0
Step 1- Determine Preliminary YG (PYG)
PYG= YG for every 0.1” of fat
NOTE: Report all PYG to the nearest tenth of a PYG- round up
Example- 0.3”= PYG- 2.75
2.75= 2.8

49. USDA Yield Grade Step 2- Determine weight adjustment adjustment
Carcass Wt
adjustment
550
-0.2
575
-0.1
600
625
+0.1
650
+0.2
675
+0.3
700
+0.4
725
+0.5
750
+0.6
775
+0.7
800
+0.8
825
+0.9
850
+1.0
875
+1.1
900
+1.2
925
+1.3
950
+1.4
Step 2- Determine weight adjustment adjustment
-Starts with a base of 600lbs and every increase in 25lbs is an increase in adjustment of 0.1
-Round on the 13
-Ex- a carcass that weighs 762lbs needs to be adjusted +0.6, but a carcass that weighs 763lbs needs to be adjusted +0.7

50. USDA Yield Grade Step 3- Determine ribeye (REA) adjustment adjustment
Ribeye area
adjustment
10.7
+0.1
11.0
11.3
-.01
11.7
-0.2
12.0
-0.3
12.3
-0.4
12.7
-0.5
13.0
-0.6
13.3
-0.7
13.7
-0.8
14.0
-0.9
14.3
-1.0
14.7
-1.1
15.0
-1.2
15.3
-1.3
15.7
-1.4
16.0
-1.5
Step 3- Determine ribeye (REA) adjustment adjustment
-Starts with a base of 11 square inches, and every increase in 1inch is an increase in adjustment of 0.3
-Easiest to call ribeyes on a “3-7-0” system. (all ribeyes end in .3, .7 or .0 as seen in the chart _

51. USDA Yield Grade Step 4- % Kidney, Pelvic and Heart Fat
% KPH
YG ADJ
5.0
+.3
4.5
+.2
4.0
+.1
3.5
0.0
3.0
-.1
2.5
-.2
2.0
-.3
1.5
-.4
1.0
-.5
0.5
-.6
Step 4- % Kidney, Pelvic and Heart Fat
Base = 3.5% +/- .5%= +/- 0.1 YG

52. USDA Yield Grade Calculation
Fat thickness = 0.5 in PYG=3.25 ≈ 3.3
HCW = 750 lb- +0.6
REA- 14.1
=3.1X0.3=-0.9
2.5% KPH= -.2
Final YG= 2.8
For this class, all yield grades are calculated to the nearest 0.1 yield grade (range: ) with no rounding