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 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 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 2.5 x 3.5 = 8.75 in2 About 5.0 in2

Heart Kidney Pelvic % KPH Fat Avg - 2.0%

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

USDA Yield Grade Short-Cut Method Step 2 Adjust PYG for REA

USDA Yield Grade Short-Cut Method Step 3 Adjust PYG for HCW

USDA Yield Grade Short-Cut Method Step 4 Adjust PYG for KPH fat %

USDA Yield Grade Short-Cut Method - Alternate Step 2 - Combine steps 2 & 3 Determine Expected REA

USDA Yield Grade Short-Cut Method - Alternate Step 2 - Combine steps 2 & 3 Adjust PYG for Expected REA

Practice Calculations Carcass Trait AFOE 0.5 REA 13.6 HCW 825 KPH 3.0 YG Formula

Practice Calculations Carcass Trait AFOE 0.5 3.25 REA 13.6 HCW 825 KPH 3.0 YG Formula

Practice Calculations Carcass Trait AFOE 0.5 3.25 REA 13.6 -0.8 HCW 825 KPH 3.0 YG Formula

Practice Calculations Carcass Trait AFOE 0.5 3.25 REA 13.6 -0.8 HCW 825 +0.9 KPH 3.0 YG Formula

Practice Calculations Carcass Trait AFOE 0.5 3.25 REA 13.6 -0.8 HCW 825 +0.9 KPH 3.0 -0.1 YG Formula

Practice Calculations Carcass Trait AFOE 0.5 3.25 REA 13.6 -0.8 HCW 825 +0.9 KPH 3.0 -0.1 YG 3.25 Formula 3.13

Practice Calculations Carcass Trait AFOE 0.75 REA 12.5 HCW 870 KPH 4.5 YG Formula

Practice Calculations Carcass Trait AFOE 0.75 3.88 REA 12.5 HCW 870 KPH 4.5 YG Formula

Practice Calculations Carcass Trait AFOE 0.75 3.88 REA 12.5 -0.5 HCW 870 KPH 4.5 YG Formula

Practice Calculations Carcass Trait AFOE 0.75 3.88 REA 12.5 -0.5 HCW 870 +1.1 KPH 4.5 YG Formula

Practice Calculations Carcass Trait AFOE 0.75 3.88 REA 12.5 -0.5 HCW 870 +1.1 KPH 4.5 +0.2 YG Formula

Practice Calculations Carcass Trait AFOE 0.75 3.88 REA 12.5 -0.5 HCW 870 +1.1 KPH 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 Palatability Smith et al., 1992 8 7 6 5 4 3 2 1 Extremely Desirable Undesirable Prime Choice Select Standard

USDA Quality Grade Carcass Maturity/Age Marbling Score Lean Color Lean Texture Lean Firmness

Carcass Maturity A 9 to 30 months B 30 to 42 months C 42 to 72 months D 72 to 96 months E 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 Moderately Abundant Slightly Abundant Modest Small Slight Traces Practically Devoid Devoid

Moderately Abundant Slightly Moderate Slight Small Modest

Relationship of Marbling to Quality Grade