Meat Goat Carcass MeritMeat Goat Carcass Merit

Dr. Dwight LovedayUniversity of Tennessee-Knoxville

Department of Food Science & Technology

Meat Animal Selection

• Selection focuses on traits associated with carcass merit

• Carcass merit– Yield of usable product (cutability)– Quality of product

Grades and Grading

• Purpose is to sort into homogenous groups to facilitate marketing

• USDA grading for beef, lamb and pork– Yield Grades to predict cutability– Quality Grades to indicate palatability;

flavor, juiciness and tenderness

Grades and Grading

Specie Yield Grade Quality Grade

Beef 1, 2, 3, 4, 5 Prime, Choice, Select, Standard

Lamb 1, 2, 3, 4, 5 Prime, Choice, Good, Utility, Cull

Pork U.S. 1, 2, 3, 4 Utility

Goat None None

Goat Carcass Cutability

• Carcass traits affecting lean meat yield– External fat

Goat Carcass Cutability

• Carcass traits affecting lean meat yield– External fat– Subcutaneous Fat

Cover Score– Goats tend to have

little fat over back muscles, unless overly fed

Subcutaneous Fat Cover Score• Subcutaneous fat

over shoulder, ribs, back and legs

• Overly fat carcasses have thin layer over back and thick cover over shoulders and ribs1: minimum/none2: rib/shoulder

covered3: excessive fat

1 2 3 Score

Goat Carcass Cutability

• Carcass traits affecting cutability– External fat– Internal fat (%KPH)

% Kidney, Pelvic & Heart Fat

• Expressed as percentage of carcass weight

1% 2% 3.5%

Goat Carcass Cutability

• Carcass traits affecting cutability– Carcass weight

• Relative body size• Body girth• Limb circumference

– Prefer carcasses less than 40 lbs– Reflection of goat type (genetics),

nutrition and management

Goat Carcass Cutability

• Carcass traits affecting cutability– External fat– Internal fat (%KPH)– Carcass weight– Muscularity

• Has less effect than fatness

• Conformation scores

Goat Carcass Cutability

• Carcass traits affecting cutability– External fat– Internal fat (%KPH)– Carcass weight– Muscularity

• Has less effect than fatness

• Muscle cross section• Conformation

– Shape– Lean to bone

Goat Carcass Conformation Scores

• Rib eye muscle difficult to measure especially in light weight carcasses

• Little fat deposition over rib eye muscle• Relative muscle thickness used to determine

conformation• Conformation expressed as a percentage• Conformation expressed as Selection scores

Selection Classes 199 TopSelection 1 150 Mid 100 Bottom

299 TopSelection 2 250 Mid 200 Bottom

399 TopSelection 3 350 Mid 300 Bottom

Selection No. 1

• Have superior meat yields

• Thick, bulging leg muscles

• Full muscling in loin & rib (back strip)

• Thick sirloin muscles• Thick shoulder

muscles

150

Selection No. 2• Have moderate

muscling• Slightly thick, bulging

leg muscles• Slightly full muscling in

loin & rib • Depression at loin/leg

junction• Slightly thick shoulder

muscles

250

Selection No. 3• Have a lower meat yield due to

carcass narrowness• Moderately full, slightly full

outside leg muscles• Shallow muscling in loin & rib • Carcass has a shrunken

appearance• Slightly thin shoulder muscles

350

Comparison of Conformation Scores

150 350250

Predication of Carcass Cutability (Texas A& M)• Lamb Cutability

Equation• % Closely Trimmed

Retail Cuts– Hot carcass wt., lbs– Adj. Fat thickness, in.– Body wall thickness,

in.– Rib Eye Area, in2.

• Developed from commercial, meat type goats

• % Semi-boneless, closely trimmed primals (leg,sirloin, loin, rack and shoulder)– Hot carcass wt., lbs– Body wall thickness, in.– Rib Eye Area, in2.

Goat Carcass Quality

• Carcass traits affecting lean quality– No muscle cross

section available– Flank Lean Color

Flank Lean Color

• Indicates physiological age

• Younger is lighter; older is darker due to greater muscle pigment

• “A” most desirableA: light grayish pink

B: moderately dark red

C: dark red B30

A30

How do you distinguish kid conformation types?

Selection 1 Market Kids

• Live goats have a superior meat type conformation; Thickly muscled throughout the body as indicated by a

– bulging outside legs

– full (rounded) back strip

– moderately thick outside shoulder

Selection 1 Market Kids

150

Selection 2 Market Kids

• Live goats have a average meat type conformation; Moderately muscled throughout the body as indicated by a

– Slightly thick outside legs

– Slightly full (rounded) back strip

– Slightly thick to slightly thin outside shoulder

Selection 2 Market Kids

250

Selection 3 Market Kids

• Live goats have an inferior meat type conformation; Thinly muscled throughout the body as indicated by a

– Legs, back and shoulders are narrow

– Body has angular, sunken appearance

Selection 3 Market Kids

370

Comparison of Live Goat Selection

1

2

3

Carcass Conformation Comparison of Live Goat Selection 1, 2 & 3

1 2 3

Selection Value Differences Slaughter Classes: Kids (Thompson Station, Oct 13, 2006)Selection 1 36-50 lbs 112.00-116.00, few 122.00 51-65 lbs 113.00-120.50, mostly 113.00-115.50 66-80 lbs 102.00-103.00 Few 84 lbs 100.00 Few 105 lbs 85.50 Few 127 lbs 75.00

Selection 2 36-50 lbs 110.00-111.00 51-65 lbs 105.00-110.00 65-80 lbs 90.00-101.00

Selection 3 25-35 lbs 100.00-110.00 36-50 lbs 104.00-106.00

51-65 lbs 100.50-105.50

2006 HLSR Champion Meat Goat

Summary• Live Goat Evaluation

– Kids for meat yield– Selection classification allows for grouping of

goat carcasses with similar characteristics for value and marketing

– Animal conformation main factor in determining value; Selection 1(Thick), 2 (Average) or 3 (Thin)

– USDA Market News Reports use Selection Classification system for price reports

Summary• Carcass Evaluation

– Selection classification allows for grouping of goat carcasses with similar characteristics for value and marketing

– Carcass Weight: < 40 pounds– Conformation Scores: Selection

1, 2 & 3– External Fat Score: 1, 2 & 3– % Kidney, Pelvic & Heart Fat– Flank Lean Color: A, B & C

Acknowledgements:

• Dr. Ken McMillin