Fall 2020 Webinar – Part IV

December 15, 2020
USDA Carcass Yield 

and Quality Standards

Dr. Bucky Gwartney

USDA Agricultural Marketing Service

Livestock and Poultry Program, Standards & Specifications Division

Bucky.Gwartney@usda.gov
“Third-Party System”

Provides confidence to buyers and sellers that an unbiased 

determination of the quality of the product has been made on which 

they can rely. 
What is the purpose behind the shield?

• Identify differences in value and utility

• Common language between buyers and sellers

• Transmit signals of value to industry and throughout 

entire marketing chain

• Assist in promotion and marketing
Grade Standards Are Applied

•Nationwide

• Uniformly

•Consistently

•Accurately

•Quickly
USDA Inspection vs. Grading

• Meat Inspection (FSIS)

• Required Service

• In order to sell meat commercially, it must 

be federally inspected.

• Funded via tax dollars

• depending on if Required or Voluntary 

service. *Species based

• Grading (AMS)

• Voluntary service

• We allow companies to sell meat as USDA 

Choice, USDA Select. 

• User – Fees Paid by Applicants

• USDA sends a bill to the packer requesting 

the service. The packer pays the USDA and 

that is how AMS is paid. 
Development of the Standards
Historical Timeline

1926

Standards 

become official

1927

Grading 

Service 

Began

1939

Grade 

changes

1941

Grade 

changes

1949

Fat color 

removed

1950

Grade 

changes

1956

Standard 

vs. 

Commercial

1965

Inc. in marbling 

to offset 

maturity; Dual 

grading system; 

Ribbed prior to 

grading

1973

Bullock separated 

from Bull;

Cutability groups 

changed to yield 

grades

1975

Min. marbling req. 

the same for 

youngest maturity 

group; 

Conformation 

eliminated; 

Coupled grades

1980

Ineligibility;

10-min bloom;

Graded only in 

carcass form & 

at slaughter est.

1987

Changed 

Good to 

Select

1989

Uncoupled 

Grades

1997

B-maturity

2008

Instrument 

Grading

2017

Adopt dentition 

to determine the 

age of the animal 

(<30 mo. or > 30 

mo.)
Major Changes

1987

Good becomes 

Select

1989

Grading uncoupled 

allowing either 

quality or yield 

grading or both

1997

Eliminated B 

maturity in low 

Choice and Select

2017

Dentition adoption -

A maturity expands 

to include C 90 bone, 

excluding 30 month 

cattle
Reasons for 

Changes

Scientific Evidence

Changing Trade Practices

New technology

Changing Market Conditions
Official Grade 

Application

• USDA graders use aids in the correct 

interpretation & application of the standards

• Marbling photographs
Official Grade ApplicationRibeye Grids

USDA graders use aids in the correct interpretation & 

application of the standards
Official Grade 

Application- PYG Rulers

USDA graders use aids in the correct interpretation & 

application of the standards
Official Grade Application- The Standards

USDA graders use aids in the 

correct interpretation & 

application of the standards
Official Grade Application- Approved Instrument 

Systems

• USDA graders use aids in the 

correct interpretation & 

application of the standards
Camera Grading- Now & In the Future

• AMS is committed to the use of technology to 

enhance our services.

• By volume, about 68% of USDA-graded beef is 

evaluated using an approved camera.

• USDA partners with the American Meat Science 

Association to review validation procedures 

through a 3rd party beef grading committee.
Grading Consistency

• Grading correlations are held annually with grading 

supervisors and throughout the year with on-line 

graders

• Over the past several years, AMS has increased inplant supervision and correlations with graders.
Quality Grade Determination

• Sex Classification

• Maturity evaluation based on evidences of skeletal maturity and 

color and texture of ribeye muscle (between 12th & 13th rib). Only if 

over 30 months. 

• Marbling and Firmness of Ribeye Muscle (between 12th & 13th rib)
Quality Grade Determination- Sex Classification

Steers, Heifers, Cows, Bullocks, Bulls
Official Grade Designation – Sex Class

Steers & Heifers•Prime

•Choice

•Select

•Standard

•Commercial

•Utility

•Cutter

•Canner

•YG 1-5

Cows •Choice

•Select

•Standard

•Commercial

•Utility

•Cutter

•Canner

•YG 1-5

Bullocks•Prime

•Choice

•Select

•Standard

•Utility

•YG 1-5

•Class identified

Cow Bullock
Quality Grade Determination - Maturity

Maturity evaluation based on evidences of 

skeletal maturity and color and texture of ribeye 

muscle (between 12th & 13th rib). Only if over 

30 months. 
Skeletal Maturity

• Sacral Vertebrae

• Lumbar Vertebrae

• Thoracic Vertebrae

• Rib bones

• Chine Bones

• Skeletal ossification occurs 

from the posterior end (rear) 

to the anterior end (head) of 

the carcass

C

A

R

C

A

S

S

M

A

T

U

R

I

T

Y
Quality Grade Determination- Ribeye

Marbling and Firmness of Ribeye Muscle 

(between 12th & 13th rib)
Lean Maturity – Color, Texture, Firmness

A20 A50 B00 C00 D00 E00 E100
Marbling- Texture

• Very fine

• Fine

• Tends to be fine

• Moderately fine

• Slightly coarse

• Coarse

• Very coarse
Firmness

Regardless of the extent to which 

marbling exceeds the minimum of a 

grade, a carcass must meet the 

minim firmness requirements for its 

maturity to qualify for that grade. 

Firm

Moderately Firm

Slightly Firm

Slightly Soft

Moderately Soft

Soft

Soft & Slightly Watery

Soft & Watery

Very Soft & Watery
Ribbing

• When both sides are ribbed, 

and the characteristics of the 

two ribeyes would justify 

different quality and/or yield 

grades, the final grade shall 

reflect the “highest” grade as 

determined from either side.
Marbling

• Influences

• Chill

• Bloom

• Lighting
Marbling 

• Fat within the muscle

• Intramuscular fat

• Evaluated on the ribeye between 

the 12th & 13th ribs
Marbling 

Evaluation

• Amount

• Texture

• Distribution
USDA Marbling Scores
USDA Quality Grade – Minimum requirement

PRIME

Select

Choice

• Ribeye is light red in color

• Ribeye has fine texture 

• Ribeye is moderately firm

• Ribeye has “slightly abundant” 

amount of marbling
USDA Quality Grade – Marbling standards

PRIME

Abundant Very Abundant
USDA Quality Grade – Minimum requirement

CHOICE

• Ribeye is moderately light red in 

color

• Ribeye has fine texture 

• Ribeye is slightly soft

• Ribeye has “small” amount marbling
USDA Quality Grade – Marbling standards

CHOICE
USDA Quality Grade – Minimum requirement

SELECT

• Ribeye is slightly light red in color

• Ribeye has fine texture 

• Ribeye is moderately soft

• Ribeye has “slight” amount 

marbling
USDA Quality Grade – Marbling standards

SELECT

Select

Choice
USDA Quality Grade – Marbling standards

STANDARD

Traces Practically Devoid
Comparison of USDA and Japanese Grading Sytems1

USDA Quality Grade USDA Marbling Score Japanese BMS Japanese Quality Grade

Prime+ Abundant 9 – 12 5

Primeo Moderately Abundant 8 5

Prime- Slightly Abundant 7 4

Choice+ Moderate 6 4

Choiceo Modest 5 4

Choice- Small 4 3

Select Slight 3 3

Standard Traces & Practically Devoid 1 & 2 1 & 2

1Cameron et al., 1994. Meat Science 38:361-364
Fat Percentage Comparison between USDA Marbling Scores 

and Japanese Beef Marbling Standards*

0

5

10

15

20

25

% Ether Extractable Fat

*Predicted values for Japanese Beef Marbling Standards for Intramuscular Fat at the 12th Rib based on 6th Rib measurements

(Zembayashi & Lunt. Meat Science 40 (1995) 211-216)
Conditions or Defects Preventing or Lowering a Grade

• Blood splash

• Carcasses can have a “small” 

amount of blood splash & still 

grade. The “small” amount is 

based on the “Slight” marbling 

card. 

• Calloused lean

• The maximum amount of calloused 

to still grade is a small amount (less 

than 1⁄2 inch)
• Dark Cutters

• Dark Cutting characteristics are determined in percentage, from 10 to 100%.

• Dark Cutting beef affects overall quality grade

• For PRIME, CHOICE, SELECT grades

• Up to 1 full grade discount

• Prime becomes Choice

• Choice becomes Select, 

• Select becomes Standard

Conditions or Defects Preventing or Lowering a Grade 

(cont.)
Before we begin our Quality Grade exercise...

• In December 2017, the standards were revised and A maturity is 

now considered up to D 0 bone without balancing skeletal and 

lean maturities. It is based strictly off the skeletal maturity. 

• If the carcass is identified as older than 30 months, then the 

grader will “balance” the skeletal maturity and lean maturity to 

get a final maturity score and ultimate quality grade 

• Remember, > 30 month of age cattle are identified on the kill floor by 

dental indentations, and will be marked as such for grading. (For example: 

3 on rounds, ribbon through feather bones, ink in the chine bones etc.)

• In short, there are grading standards for regular cattle, and 

standards for 30 month cattle.
Balancing Skeletal & Lean Maturities

> 30 month of age

When skeletal maturity 

(bone) differs from lean 

maturity, slightly more 

emphasis is placed on the 

skeletal evidences.

In no case can the overall 

maturity be more than 

one full maturity group 

different than indicated by 

the skeletal differences. 
Example of thoracic buttons and ossification to bone
Example of thoracic buttons and ossification to bone (cont.)
Camera Grading: Upgrading & Downgrading

• If a grader calls marbling 20 degrees higher or lower 

than the camera, the grade should be adjusted. 

CAMERA CALL: SIDE 1 CAMERA CALL:

SIDE 2

GRADER CALL UPGRADE, DOWNGRADE, 

NO CHANGE

370 (Slight 70) 380 (Slight 80) 400 (Small 0) UPGRADE: CHOICE

530 (Modest 30) 500 (Modest 0) 480 (Small 80) Downgrade from G1 to 

Choice or stays Choice

690 (Moderate 90) 690 (Moderate 90) 700 (SLAB 0) NO CHANGE: CHOICE

410 (Small 10) 400 (Small 0) Slight 80 DOWNGRADE: SELECT
Quality Evaluation

Exercise
Which component of the yield grade has the greatest influence on 

final yield grade?

A Carcass Weight

B Lean Color

C Subcutaneous Fat (backfat)

D Intramuscular Fat (marbling)
USDA Marbling Standards

0 – 100 degrees
USDA Quality Grade – Marbling standards

PRIME – Slightly Abundant, Moderately Abundant

Abundant Very Abundant
USDA Quality Grade – Marbling standards

CHOICE- Small, Modest, Moderate
USDA Quality Grade – Marbling standards

PREMIUM CHOICE or upper 2/3
USDA Quality Grade – Marbling standards

SELECT- Slight

Select

Choice
USDA Quality Grade – Marbling standards

STANDARD- Traces, Practically Devoid

Traces Practically Devoid
Training Time...

* 5 ribeyes

* Marbling call and USDA grade call
Training #1

Slight 10 

– Low Select -
Training #2

Slight 50

– High Select -
Training #3

Small 80

– Low Choice -
Training #4

Moderate 80 

– High Choice -
Training #5

Slightly Abund. 10 

– Low Prime -
READY???

* 15 ribeyes

* 10 seconds for each one

* Just call the final Quality Grade of Prime, Choice, Select

Here we go!!!
These 15 carcasses were from the 

2020 American Royal Meat 

Judging contest put on by AMSA
How did you do???

Scoring:

*10 points for correct

*5 points for one grade off

*0 point for more than one grade off

Total of 150 points
Choice

High Choice Md 40

# 1
Choice

Average Choice Mt 30 # 2
Choice

Average Choice Mt 10 # 3
Select

Low Select Sl 40 # 4
Choice

Average Choice Mt 40 # 5
Choice

High Choice Md 70 # 6
Choice

Average Choice Mt 50 # 7
Prime

Low Prime Slab 10 # 8
Choice

High Choice Md 60 # 9
Choice

Average Choice Mt 40 # 10
Choice

High Choice Md 80 # 11
Choice

Low Choice Sm 80 # 12
Select

High Select Sl 50 # 13
Select

Low Select Sl 30 # 14
Select

Low Select Sl 10 # 15
Calculating Yield Grades

This Photo by Unknown Author is licensed under CC BY-ND
Yield Grade 

Factors

Thickness of fat over the ribeye (backfat)

Ribeye area

Percentage of kidney, pelvic, heart fat 

(KPH)

Hot Carcass Weight
Yield Grade Factors- Thickness of fat over 

the ribeye (backfat)
Yield Grade FactorsRibeye Area
Yield Grade Factors- Hot Carcass Weight
Yield Grade Factors - Percentage 

of kidney, pelvic, heart fat (KPH)
Yield Grade Factors- Percentage 

of kidney, pelvic, heart fat (KPH)

Kidney
Yield Grade FactorsPercentage of KPH

Pelvic
Yield Grade Factors- Percentage 

KPH

Heart
Yield Grade 

Determination

Yield Grade 

Equation

Short – Cut 

Method
Yield Grade Equation – Long version

2.50 

+ (2.50 x adjusted fat thickness, inches) 

+ (0.20 x percent kidney, pelvic and heart fat) 

+ (0.0038 x hot carcass weight, pounds) 

– (0.32 x ribeye area, square inches)
Short Cut Method:

Preliminary Yield Grade (PYG)

The PYG is determined based on the thickness of fat 

over the ribeye muscle. A carcass with no fat opposite 

to ribeye has a PYG of 2.00. For each .1 inch of fat add 

.25 to the PYG

The measurement is adjusted, either up or down, if 

necessary, to reflect unusual amounts of fat on other 

parts of the carcass.

Adjustments are made in tenths. 

If the back fat 

measures...

The PYG will be...

0.00 2.0

.20 2.5

.40 3.0

.60 3.5

.80 4.0

1.0 4.5

1.2 5.0

1.4 5.5

1.6 6.0
Short Cut Method:

REA/HCW Adjustment

Adjustments are made to the adjusted preliminary 

yield grade for variations in actual REA from the 

REA/HCW chart. 

Difference multiplied by 0.3

A larger than normal REA = SUBTRACT

A smaller than normal REA = ADD

Adjustments are made in tenths. 

Hot Carcass 

Weight 

Ribeye Area

500 9.8

600 11.0

700 12.2

800 13.4

900 14.6

1000 15.8

1100 17.0
Short Cut Method:

KPH Fat Adjustment

Adjustments are made to the adjusted PYG for 

variations in the % KPH from normal (3.5%)

For every 0.5% LESS than 3.5%, a tenth is subtracted

For every 0.5% MORE than 3.5, a tenth is added

KPH Adjustment

6.0% + 0.5

5.5% + 0.4

5.0% + 0.3

4.5% + 0.2

4.0% + 0.1

3.5% (normal) ----------

3.0% - 0.1

2.5% - 0.2

2.0% - 0.3

1.5% - 0.4

1.0% - 0.5

0.5% - 0.6
Short Cut Method:

Fractional Parts

All adjustments to the PYG are made 

in tenths. 

For grading purposes, the final yield grade 

is a whole number. All fractional parts are 

dropped. 

For carcass evaluation purposes, 

fractions may be reported. 
Yield Grade Determination- Yield Grade

Short cut method

• Start with estimating the PYG – Ex. .4 inches = PYG of 3.0

• Get HCW – Know the REQUIRED REA needed for that weight

• Ex. An 800 pound carcass needs a 13.4 sq. inch REA

• Estimate ACTUAL REA (sq. inches) and multiply the difference by .3

• Ex. Actual REA is 15.4, so 15.4-13.4 = 2.0 sq. inches

• 2.0 x .3 = .6

• Subtract this value from the PYG so 3.0 - .6 = 2.4 (we subtract because the 

ACTUAL carcass REA is MORE than REQUIRED, so it has more muscle and 

will result in a lower numerical YG that results in a higher cutability)
Yield Grade Determination...

Yield Grade Equation – Short cut method

• Now estimate the % of KPH, based on the HCW

• Ex. KPH estimated at 3.0 % (would be an actual weight of 24 pounds)

• Subtract .1 from the value you have calculated so far (we subtract 

because the % KPH is less than the baseline of 3.5 (no plus or minus) so it 

has less fat and thus will result in a lower numerical YG that results in a 

higher cutability)

• 3.0 - .6 = 2.4 - .1 = 2.3

• So 2.3 is the final CALCULATED yield grade with YG 2 being the actual YG 

applied
Yield Grade Example 1

HCW PYG REA REQ. Act. REA KPH KPH ADJ. FYG

639 2.6 11.4 12.4 2.0 -0.3 2.0

1. PYG of 2.6

2. A 639# carcass needs an 11.4” ribeye

12.4 – 11.4 = 1 x 0.3 = 0.3

Because the actual ribeye is bigger than the required 

ribeye size, we subtract.

3. KPH is 2.0% and according to the KPH chart, the 

adjustment for 2.0% = -0.3

PYG: 2.6

REA : -0.3

KPH : -0.3

_____________

2.0 
Yield Grade Example 2

HCW PYG REA REQ. Act. REA KPH KPH ADJ. FYG

815 2.7 13.5 13.1 2.5 -0.2 2.6

1. PYG of 2.7

2. A 815# carcass needs a 13.5” ribeye.

13.5 – 13.1 = 0.4 x 0.3 = 0.12

Because the actual ribeye size is smaller than the 

required ribeye size, we add

3. KPH % is 2.5 and according to the KPH chart, the 

adjustment for 2.5% = -0.2

PYG: 2.7

REA : +0.1

KPH : -0.2

_____________

2.6
Yield Grade Evaluation

Exercise
Which component of the yield grade calculation has the greatest 

influence on final yield grade?

A Estimated % kidney-pelvic-heart fat (KPH)

B 12th rib fat thickness (PYG)

C Hot carcass weight (HCW)

D Ribeye area (REA)
Training Time Again...

* 5 ribeyes

* USDA Yield Grade call
PYG of 3.2

HCW = 967 - NEEDS 15.4 – Has 15.6 so subtract .06 (.2 x .3)

KPH = 2.0% - Subtract .3

Final YG = 2.8 or YG 2
PYG of 3.3

HCW = 925 - NEEDS 14.9 – Has 15.7 so SUBTRACT .24 (.8 x .3)

KPH = 3.0% - Subtract .1

Final YG = 3.0 or YG 3
PYG of 3.3

HCW = 875 - NEEDS 14.3 – Has 13.6 so ADD .21 (.7 x .3)

KPH = 3.5% - No change

Final YG = 3.5 or YG 3
PYG of 3.8

HCW = 941 - NEEDS 15.0 – Has 13.8 so ADD .36 (1.2 x .3)

KPH = 4.5 % - Add .2

Final YG = 4.4 or YG 4
PYG of 4.0

HCW = 1075 - NEEDS 16.7 – Has 11.5 so ADD 1.56 (5.2 x .3)

KPH = 3.0% - Add .3

Final YG = 5.9 or YG 5
READY???

* 15 ribeyes

* 10 seconds for each one

* Just call the final YG of 1, 2, 3, 4, 5

Here we go!!!
How did you do???

Scoring:

*10 points for correct

*5 points for one Yield Grade off

*0 point for more than one YG off

Total of 150 points
PYG = 3.6

HCW = 950 – NEEDS 

15.2 – HAS 14.2 

KPH = 3.5%

Final YG of 3.9 or 

YG 3

# 1
PYG = 3.3

HCW = 925 - NEEDS 14.9 – HAS 15.7 

KPH = 3.0%

Final YG of 3.0 or YG 3

# 2
PYG = 3.4

HCW = 985 - NEEDS 15.6 – HAS 14.0

KPH = 4.0%

Final YG of 4.0 or YG 4

# 3
PYG = 3.0

HCW = 890 - NEEDS 14.4 – HAS 14.8

KPH = 4.5%

Final YG of 3.0 or YG 3

# 4
PYG = 3.3

HCW = 875 - NEEDS 14.3 – HAS 13.6

KPH = 3.5%

Final YG of 3.5 or YG 3

# 5
PYG = 3.8

HCW = 941 - NEEDS 15.1 – HAS 13.8 

KPH = 4.5%

Final YG of 4.4 or YG 4

# 6
PYG = 3.5

HCW = 1065 - NEEDS 16.5 – HAS 14.4 

KPH = 2.0%

Final YG of 3.8 or YG 3

# 7
PYG = 3.8

HCW = 1095 - NEEDS 16.9 – HAS 13.4

KPH = 5.0%

Final YG of 5.1 or YG 5

# 8
PYG = 3.7

HCW = 955 - NEEDS 15.7 – HAS – 13.5

KPH = 3.5%

Final YG of 4.2 or YG 4

# 9
PYG = 4.4

HCW = 1010 - NEEDS 15.9 – HAS 12.6

KPH = 3.0%

Final YG of 5.3 or YG 5

# 10
PYG = 3.3

HCW = 998 - NEEDS 15.7 – HAS 14.3

KPH = 4.5%

Final YG of 3.9 or YG 3

# 11
PYG = 4.3

HCW = 987 - NEEDS 15.6 – HAS 13.6

KPH = 3.0%

Final YG of 4.8 or YG 4

# 12
PYG = 4.0

HCW = 1075 - NEEDS 16.7 – HAS 11.5

KPH = 5.0%

Final YG of 5.9 or YG 5

# 13
PYG = 3.2

HCW = 967 - NEEDS 15.4 – HAS 15.6 

KPH = 2.0%

Final YG of 2.8 or YG 2

# 14
PYG = 3.7

HCW = 1017 - NEEDS 16.0 – HAS 15.9

KPH = 3.5%

Final YG of 3.7 or YG 3

# 15
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