1. Market Lamb Evaluation
Compiled By:
Jared Jackson
Tarleton State University

2. Quality Grade
Maturity
Flank Fat Streaking
Leg Conformation Score

3. Maturity Break joint vs Spool joint Break joint (Lamb)
Spool joint (Mutton)

4. Other Maturity Factors
Color of the ribs
Size and shape of the ribs

5. Flank Fat Streaking
Intramuscular fat in the flank
Similar to Marbling

6. Leg Conformation Score
Circumference of the Leg of Lamb
It is a subjective judgment
Minimal Affect on Final Quality Grade

7. Determining Quality Grade

8. Sheep Quality Grades Lamb Quality Grades- Mutton Quality Grades-
Prime, Choice, Good, Utility
Mutton Quality Grades-
Choice, Good, Utility, Cull
Annually, typically 90% of lamb carcasses will grade Prime or Choice

9. Dressing Percent 50-55% in the typical range in dressing percent
Dressing Percent= (HCW/Live Weight) X 100
Factors affecting dressing percent
Fill
Finish
Muscling
Sex
Fleece Weight

10. Muscling in Sheep Objectively measured my REA and leg circumference
Split Carcass Between the 12th and 13th rib
Measure both cross-sections of the longissmus dori muscles
Then average the 2 together
REA range- 2.0 – 5.0 square inches

11. Muscling in Sheep

12. Fat Measured between the 12th and 13th rib
Measured at ½ the chine bone on both Longissmuss dorsi cross-sections
The 2 measurement are averaged together
Ideal Range: .05”-0.2”
Typical Range: .01”-0.5”
Lambs with more than .25” are unacceptable

13. Body Wall Measured between the 12th and 13th rib
Measured 4” away from the chine bone
Includes Fat, Bone, and Muscle

16. Determining Cutability in Market Lambs
Yield Grade
Similar to cattle
Yield Grade= .4 + (10 X FT)

17. Percent Boneless Closely Trimmed Retail Cuts
Much more accurate
Typical range 40%-60%
Percent Boneless Closely Trimmed Retail Cuts=
( X HCW) – (4.376 X FT) – (3.53 X Body Wall) + (2.456 X REA)

18. Market Lamb Pricing

19. Example $114.55 = Final Live Price per cwt $179.84= Total Lamb Value
(Live Weight X Dressing Percent)=
157 X .54= 84.8= HCW
Example
Specifications-
QG- Prime
YG- 4.2
Live Weight lbs.
Wool- Unshorn
Description- Black-Face
Gender- Ram
Total Value-
157 X =
$179.84= Total Lamb Value
Live Price per Pound-
Base Price:$236cwt
Yield Grade Deduction-
( = 1.2) X 10= 12 X $.60= -$7.20
$236-$7.20= $228.80cwt= Carcass Price
Conversion of Carcass Price to Live Price-
$ X .54= $123.55cwt= Live Price
Live Price Deductions-
$ $5.00- $4.00=
$ = Final Live Price per cwt