Qualitative Evaluation

1
Qualitative Evaluation

• Evaluated by USDA Quality Grade
• Factors influencing Quality Grade
• Direct
• Marbling
• Maturity
• Indirect
• Texture
• Firmness
• Color

2
Why is marbling so Important?

• Prime 1 in 26
• Upper 2/3 of Choice 1 in 19
• Lower 1/3 of Choice 1 in 7
• Select 1 in 5
• Standard 1 in 2

• Quality Grade Odds

• Odds of getting a steak that is slightly
  undesirable or worse in overall palatability

3
Marbling

• Abundant
• Moderately Abundant
• Slightly Abundant
• Moderate
• Modest
• Small
• Slight
• Traces
• Practically devoid
• Devoid

Greatest
Leanest
4
Modest Choiceo
Moderately Abundant Primeo
5
Modest Choiceo
Slightly Abundant Prime-
6
Moderate Choice
Modest Choiceo
7
Modest Choiceo
Small Choice-
8
Modest Choiceo
Slight Select
9
Moderately Abundant Primeo
Slightly Abundant Prime-
Moderate Choice
Modest Choiceo
Small Choice-
Slight Select
10
(No Transcript)
11
Sex Effects

• At comparable weights frame sizes
• Heifers will have slightly more marbling
• Bulls will have slightly less marbling

12
Maturity

• Included because age influences eating quality
• Tenderness
• Juiciness
• Flavor
• Physiological age, not chronological age
• Represents point on growth curve animal has
  reached at slaughter

13

• Determined by ossification of bones/joints
• Vertebrae
• Sacral
• Lumbar
• Thoracic
• Ribs
• Color/texture of ribeye muscle

14
Maturity Grade Changes

• The older the animal, the more variability in the
  eating characteristics
• Since January, 1997
• Select grade only applies to A maturity cattle
• Marbling required for Choice grade was increased
• Affects
• Older feeder cattle, e.g. Mexican steers
• Heiferettes - 2-yr old females that did not get
  pregnant, and were sold as fed cattle

15
3 Minor factors Affecting Quality Grades

• Muscle texture
• Muscle color
• Firmness

16
(No Transcript)
17
Quantitative Evaluation

• Evaluated by USDA Yield Grade (1965)
• Estimate of the edible portion of the four primal
  cuts

Thinnest, Leanest Wastiest, Fattest
1 2 3 4 5
High Low
Yield Grade
Cutability
18
High
Negative Correlation
Cutability
Low
1
2
3
4
5
Yield Grade
19
(No Transcript)
20
Factors Affecting Yield Grade

• Fat thickness over 12th Rib
• Percent internal (KPH) fat
• Carcass Weight
• Ribeye Area (REA)

21
Yield Grade Calculations

• Regression Equation

YG 2.50 2.5 x (inches backfat) 0.20 x
(KPH) 0.0038 x (lb Hot Carcass Weight) -
0.32 x (REA in2)
22
Yield Grade Calculations

• Using Correction Factors to adjust preliminary
  yield grade
• Preliminary yield grade is based on backfat

Backfat (inches) PYG 0.2 2.5 0.4 3.0 0.6 3.5
0.8 4.0 1.0 4.5
23
Backfat

• Depth of fat over the ribeye muscle at the 12th
  rib. Single measurement 3/4 of the lateral
  length of the ribeye muscle.
• Every 0.2 inches of backfat is worth 0.5 yield
  grade units

24
(No Transcript)
25
Carcass Weight Adjustment

• Base - 600 lbs
• Rule
• If HCW gt base, add to PYG
• If HCW lt base, subtract from PYG
• Amount to add/subtract
• 0.4 YG units per 100 pounds deviation, or
• 0.1 YG units per 25 pounds deviation
• Example
• 700 lb carcass, add 0.4 YG units to PYG
• 550 lb carcass, subtract 0.2 YG units from PYG

26
Ribeye Area

• Definition - Area of the longissimus muscle
  measured at in squared inches at the 12th rib
  interface on the beef forequarter.
• Normal range - 10.0 to 18.0 in2
• Bulls will average about 1 in2 larger than
  steers, and heifers will average about 1 in2 less
  than steers of same weight.

27
Ribeye Area Measurement

• Use grid, count the dots
• Make outline with acetate paper, and use outline
  for estimation

28
REA Adjustment

• Base - 11 in2
• Rule
• If REA gt base, subtract from PYG
• If REA lt base, add to PYG
• Amount to add/subtract
• 0.3 YG units per 1 in2 deviation
• Example
• 12 in2 REA, subtract 0.3 YG units from PYG
• 9 in2 REA, add 0.6 YG units to PYG

29
Internal Fat

• Kidney, Pelvic and Heart fat
• Definition - The internal carcass fat associated
  with the kidney, pelvic cavity, and heart
  expressed as a percentage of chilled carcass
  weight
• As KPH increases, cutability decreases.
  Therefore, yield grade increases in numerical
  value.

30
5 KPH
2.5 KPH
31
How to Predict KPH in Live Animal
Positive Correlation
32
KPH

• Normal range 1-4.5
• Dairy cattle will average about 1.5 more than
  beef cattle of the same weight

33
KPH Adjustment

• Base - 3.5
• Rule
• If KPH gt base, add to PYG
• If KPH lt base, subtract from PYG
• Amount to add/subtract
• 0.2 YG units per 1 deviation, or
• 0.1 YG units per .5 deviation
• Example
• 4 KPH, add 0.1 YG units to PYG
• 2.5 KPH, subtract 0.2 YG units from PYG

34
Example Animal

• 700 lb carcass
• 0.6 inches backfat
• 3 KPH
• 13 in2 REA

• PYG 3.5
• Carcass weight adjustment 0.4
• REA adjustment -.6
• KPH adjustment -.1
• Final yield grade 3.2