2USDA’s Dual Grading System Yield Grade1, 2, 3, 4, 5expected yield of closely-trimmed cuts from the leg, loin, rack, and shoulder (80% of the weight and 90% of the valueQuality GradePrime, Choice, Good, Utility, Cullpredicts expected palatability (tenderness, juiciness, flavor)
3Determination of Class and Kind Class – Ewe, Wether, Ram1. Udder (smooth) or cod fat (rough)2. ConformationYearling muttonP,C,G,U / 1 – 512 – 25 monthspool or imperfect break jointsslightly to mod., dk. red flankmod wide / flat/ reddish ribs3. Mutton> 24 monthsspool jointsdark to very dk. red flankwide, flat, white ribsKind – MaturityLamb (A/B)P,C,G,U,C / 1 - 52 – 14 monthat least one perfect break jointslightly dark, pink flankround / red ribs
5USDA Yield GradePurpose to segregate carcasses into cutablity groups based on the expected yield of closely-trimmed cuts from the leg, loin, rack, and shoulder (80% of the weight and 90% of the valueExpected YieldsYG 1 – 49.8% or moreYG 2 – 49.7% %YG 3 – 48.4% %YG 4 – 47.1% %YG 5 – 45.8% or less
6USDA Yield Grade USDA Yield Grades – 1, 2, 3, 4, 5 - Avg yield grade of US lambcarcasses is upper 3USDA YG = (10 x 12th rib fat) + 0.4
7USDA Quality GradePredicts the eating quality of cooked lamb cuts from the Shoulder, Rack, Loin, and Leg– (Prime +,◦,-; Choice +,◦,-; Good +,◦,-; Utility, Cull)– 90+% of U.S. lamb carcasses grade Pr or ChBased on:Maturity (lamb, yearling mutton, mutton)Flank streaking (Traces, Slight, Small, Modest, etc.)Conformation (Prime +,◦,-; Choice +,◦,-; Good +,◦,-)Flank and fat firmnessMinimum fat thickness
10Preliminary Quality Grade Adjustments for Conformation Must have minimum Prime PQG for Prime grade.In P & Ch, superior PQG can compensate for inferior conf. on an equal basis.In Choice, superior conf. can compensate for inferior PQG on an equal basis for 1/3 grade.In Good, PQG and conformation can compensate for each other on an equal basis for 1/3 grade.
11Criteria for Placing Lamb Carcasses 1. Trimness / Fatness2. Muscling3. Dimension / WeightMinimum Quality – Prime and Choice