Market Lamb Evaluation Compiled By: Jared Jackson Tarleton State University

Quality Grade Maturity Flank Fat Streaking Leg Conformation Score

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

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

Flank Fat Streaking Intramuscular fat in the flank Similar to Marbling

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

Determining Quality Grade

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

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

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

Muscling in Sheep

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

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

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

Percent Boneless Closely Trimmed Retail Cuts Much more accurate Typical range 40%-60% Percent Boneless Closely Trimmed Retail Cuts= 49.936 - (0.0848 X HCW) – (4.376 X FT) – (3.53 X Body Wall) + (2.456 X REA)

Market Lamb Pricing

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- 157 lbs. Wool- Unshorn Description- Black-Face Gender- Ram Total Value- 157 X 1.1455= $179.84= Total Lamb Value Live Price per Pound- Base Price:$236cwt Yield Grade Deduction- (4.2-3.0= 1.2) X 10= 12 X $.60= -$7.20 $236-$7.20= $228.80cwt= Carcass Price Conversion of Carcass Price to Live Price- $228.80 X .54= $123.55cwt= Live Price Live Price Deductions- $123.55- $5.00- $4.00= $114.55 = Final Live Price per cwt