Transcript Cool Blue Water Fade

Meat Goat Carcass Merit
Dr. Dwight Loveday
University 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
Pork
U.S. 1, 2, 3, 4
Prime, Choice,
Good, Utility, Cull
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
ribs
 1: minimum/none
 2: rib/shoulder
covered
 3: excessive fat
1
2
Score
3
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
Selection 1
199
150
100
Selection 2
299 Top
250 Mid
200 Bottom
Selection 3
399 Top
350 Mid
300 Bottom
Top
Mid
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
250
350
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 desirable
A: light grayish pink
B: moderately dark red
C: dark red
A30
B30
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
1
Comparison
of Live Goat
Selection
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