BEEF CARCASSYIELD 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 Grade 1 > 52.4% Yield Grade 2 50.0 - 52.3% Yield Grade 3 47.7 - 50.0% Yield Grade 4 45.4 - 47.7% Yield Grade 5 < 45.4%

USDA Yield Grade

12th Rib Backfat Ribeye Area % Kidney, Pelvic, Heart Fat

Hot Carcass Weight

12th RibBackfat

3/4 of thelongitudinallength of theribeye muscle

Avg - .5 inRange - .15 - .80

RibeyeArea

Average - 12.8 in2

Range - 10.0 - 18.0 in2

Estimating Ribeye Area Can estimate length x width

Other references

2.5 x 3.5 = 8.75 in2About 5.0 in2

% KPHFat

Heart

Kidney

Pelvic

Avg - 2.0%

Hot CarcassWeight

UsuallyGiven

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 GradeShort-Cut Method

Step 1– Determine Preliminary Yield Grade

AFOE PYG.2 2.50.3 2.75.4 3.00.5 3.25.6 3.50

USDA Yield GradeShort-Cut Method

Step 2– Adjust PYG for REA

REA PYG ADJ .9.0 +.610.0 +.311.0 0.012.0 -.313.0 -.6

USDA Yield GradeShort-Cut Method

Step 3– Adjust PYG for HCW

HCW PYG ADJ.575 -.1600 0.0625 +.1650 +.2700 +.4

USDA Yield GradeShort-Cut Method

Step 4– Adjust PYG for KPH fat %

KPH PYG ADJ.2.0 -.32.5 -.23.0 -.13.5 0.04.0 +.1

USDA Yield GradeShort-Cut Method - Alternate

Step 2 - Combine steps 2 & 3– Determine Expected REA

HCW Exp. REA575 10.7600 11.0625 11.3650 11.6700 12.2

USDA Yield GradeShort-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 0.5REA 13.6HCW 825KPH 3.0

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.5 3.25REA 13.6 HCW 825KPH 3.0

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.5 3.25REA 13.6 -0.8HCW 825KPH 3.0

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.5 3.25REA 13.6 -0.8HCW 825 +0.9KPH 3.0

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.5 3.25REA 13.6 -0.8HCW 825 +0.9KPH 3.0 -0.1

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.5 3.25REA 13.6 -0.8HCW 825 +0.9KPH 3.0 -0.1

YG 3.25

Formula 3.13

Practice Calculations

Carcass Trait

AFOE 0.75REA 12.5HCW 870KPH 4.5

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.75 3.88REA 12.5HCW 870KPH 4.5

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.75 3.88REA 12.5 -0.5HCW 870KPH 4.5

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.75 3.88REA 12.5 -0.5HCW 870 +1.1KPH 4.5

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.75 3.88REA 12.5 -0.5HCW 870 +1.1KPH 4.5 +0.2

YG

Formula

Practice Calculations

Carcass Trait

AFOE 0.75 3.88REA 12.5 -0.5HCW 870 +1.1KPH 4.5 +0.2

YG 4.68

Formula 4.58

USDA Quality Grade

Estimates Eating Characteristics– Tenderness, Juiciness, Flavor

USDA Prime USDA Commercial USDA Choice USDA Utility USDA Select USDA Cutter USDA Standard USDA Canner

Relationship of Quality Grade

and PalatabilitySmith et al., 1992

8 7 6 5 4 3 2 1ExtremelyDesirable

ExtremelyUndesirable

Prime

Choice

Select

Standard

USDA Quality Grade

Carcass Maturity/Age Marbling Score

Lean Color Lean Texture Lean Firmness

Carcass Maturity

A 9 to 30 monthsB 30 to 42 monthsC 42 to 72 monthsD 72 to 96 monthsE more than 96 months

Carcass Maturity Based on bone

ossification

Order:SacralLumbarThoracic

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

Moderately

Abundant

Slightly Abundant

Moderate

Modest

Small

Slight

Traces

Practically

Devoid

Devoid

ModeratelyAbundant

SlightlyAbundant Moderate

SlightSmallModest

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