Transcript Beef Carcass Evaluation

BEEF CARCASS
YIELD AND QUALITY
GRADING
South Carolina Meat Judging Workshop
USDA Beef Carcass Grades
 Purpose:
Classify Carcasses
« Expected Cutability or Retail Yield
« Expected Eating Quality
Conformation
Dictates
Composition
USDA Yield Grade
 Estimates
- % Closely-Trimmed,
Boneless Retail Cuts From Chuck,
Rib, Loin and Round
 Yield
 Yield
 Yield
 Yield
 Yield
Grade 1
Grade 2
Grade 3
Grade 4
Grade 5
> 52.4%
50.0 - 52.3%
47.7 - 50.0%
45.4 - 47.7%
< 45.4%
USDA Yield Grade
12th Rib Backfat
 Ribeye Area
 % Kidney, Pelvic, Heart Fat
 Hot Carcass Weight

12th Rib
Backfat
3/4 of the
longitudinal
length of the
ribeye muscle
Avg - .5 in
Range - .15 - .80
Ribeye
Area
Average - 12.8 in2
Range - 10.0 - 18.0 in2
Estimating Ribeye Area
 Can

estimate length x width
Other references
About 5.0 in2
2.5 x 3.5 =
8.75 in2
Pelvic
% KPH
Fat
Kidney
Avg - 2.0%
Heart
Hot Carcass
Weight
Usually
Given
USDA Yield Grade
 Equation
2.5
+ (2.5 x 12th Rib Backfat, in.)
- (0.32 x Ribeye Area, sq in.)
+ (0.20 x KPH Fat, %)
+ (0.0038 x Hot Carcass Wt, lbs.)
USDA Yield Grade
Short-Cut Method
 Step
1
– Determine Preliminary Yield Grade
AFOE
.2
.3
.4
.5
.6
PYG
2.50
2.75
3.00
3.25
3.50
USDA Yield Grade
Short-Cut Method
 Step
2
– Adjust PYG for REA
REA
9.0
10.0
11.0
12.0
13.0
PYG ADJ.
+.6
+.3
0.0
-.3
-.6
USDA Yield Grade
Short-Cut Method
 Step
3
– Adjust PYG for HCW
HCW
575
600
625
650
700
PYG ADJ.
-.1
0.0
+.1
+.2
+.4
USDA Yield Grade
Short-Cut Method
 Step
4
– Adjust PYG for KPH fat %
KPH
2.0
2.5
3.0
3.5
4.0
PYG ADJ.
-.3
-.2
-.1
0.0
+.1
USDA Yield Grade
Short-Cut Method - Alternate
 Step
2 - Combine steps 2 & 3
– Determine Expected REA
HCW
575
600
625
650
700
Exp. REA
10.7
11.0
11.3
11.6
12.2
USDA Yield Grade
Short-Cut Method - Alternate
 Step
2 - Combine steps 2 & 3
– Adjust PYG for Expected REA
Act – Exp PYG ADJ.
-2.0
+.6
-1.0
+.3
0.0
0.0
+1.0
-.3
+2.0
-.6
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.5
13.6
825
3.0
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.5
13.6
825
3.0
3.25
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.5
13.6
825
3.0
3.25
-0.8
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.5
13.6
825
3.0
3.25
-0.8
+0.9
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.5
13.6
825
3.0
3.25
-0.8
+0.9
-0.1
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
0.5
13.6
825
3.0
3.25
-0.8
+0.9
-0.1
YG
3.25
Formula
3.13
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.75
12.5
870
4.5
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.75
12.5
870
4.5
3.88
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.75
12.5
870
4.5
3.88
-0.5
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.75
12.5
870
4.5
3.88
-0.5
+1.1
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
YG
Formula
0.75
12.5
870
4.5
3.88
-0.5
+1.1
+0.2
Practice Calculations
Carcass Trait
AFOE
REA
HCW
KPH
0.75
12.5
870
4.5
3.88
-0.5
+1.1
+0.2
YG
4.68
Formula
4.58
USDA Quality Grade
 Estimates
Eating Characteristics
– Tenderness, Juiciness, Flavor
 USDA Prime
 USDA Choice
 USDA Select
 USDA Standard
 USDA Commercial
 USDA Utility
 USDA Cutter
 USDA Canner
Relationship of Quality Grade
and Palatability
Smith et al., 1992
Prime
Choice
Select
Standard
8
7
Extremely
Desirable
6
5
4
3
2
1
Extremely
Undesirable
USDA Quality Grade
Carcass Maturity/Age
 Marbling Score

 Lean Color
 Lean Texture
 Lean Firmness
Carcass Maturity
A
B
C
D
E
9 to 30 months
30 to 42 months
42 to 72 months
72 to 96 months
more than 96 months
Carcass Maturity
 Based
on bone
ossification
 Order:
Sacral
Lumbar
Thoracic

A maturity

Note cartilage in
buttons on tip of
chine bone

No evidence of
bone

D maturity

Note ossification
of buttons on tip
of chine bone
USDA Marbling Score

Abundant

Small

Moderately Abundant

Slight

Slightly Abundant

Traces

Moderate

Practically Devoid

Modest

Devoid
Moderately
Abundant
Modest
Slightly
Abundant
Moderate
Small
Slight
Relationship of Marbling to
Quality Grade
Prime +
Ab
Select +
Sl 50 -100
Prime o
MAb
Select -
Sl 00 - 49
Prime -
SlAb
Std
+
Tr 66 – 100
Choice +
Mdt
Std
o
Pd67 – Tr33
Choice o
Md
Std
-
Pd 00-66
Choice -
Sm