Education

Specifications for Official U.S. Standards for Yield Grades of Slaughter Lambs, Yearlings, and Sheep

Yield Grade 1
Yield Grade 1 slaughter lambs, yearlings, and sheep produce carcasses which have very high yields of boneless retail cuts. Animals with characteristics qualifying them for the lower limits of Yield Grade 1 (near the borderline between Yield Grade 1 and Yield Grade 2) will have only a slightly thin covering of external fat over the back, loin, and ribs, and a slightly thick covering of fat over the rump. In handling, the backbone, ribs, and ends of bones at the loin edge are slightly prominent. A carcass produced from slaughter animals of this description might have a 0.15 inch of fat over the ribeye.

Yield Grade 2
Yield Grade 2 slaughter lambs, yearlings, and sheep produce carcasses which have high yields of boneless retail cuts. Animals with characteristics qualifying them for the lower limits of Yield Grade 2 will have a slightly thick covering of external fat over the back, loin, and ribs, and a thick covering of fat over the rump. They tend to be slightly deep and full through the flanks, and the brisket and cod or udder are moderately full. In handling, the backbone, ribs, and ends of bones at the loin edge are readily discernible. A carcass produced from slaughter animals of this description might have a 0.25 inch of fat over the ribeye.

Yield Grade 3
Yield Grade 3 slaughter lambs, yearlings, and sheep produce carcasses which have intermediate yields of boneless retail cuts. Animals with characteristics qualifying them for the lower limits of Yield Grade 3 will have a thick covering of external fat over the back and loin, and a very thick covering of fat over the rump and down over the ribs. The flanks are deep and full, and the brisket and cod or udder are full. In handling, the backbone, ribs, and ends of bones at the loin edge are difficult to distinguish. A carcass produced from slaughter animals of this description might have a 0.35 inch of fat over the ribeye.

Yield Grade 4
Yield Grade 4 slaughter lambs, yearlings, and sheep produce carcasses which have moderately low yields of boneless retail cuts. Animals with characteristics qualifying them for the lower limits of Yield Grade 4 will have a very thick covering of external fat over the back and loin, and an extremely thick covering of fat over the rump and down over the ribs. The flanks are moderately deep and full, and the brisket and cod or udder are full. In handling, the backbone, ribs, and ends of bones at the loin edge are not discernible. A carcass produced from slaughter animals of this description might have a 0.45 inch of fat over the ribeye.

Yield Grade 5
Yield Grade 5 slaughter lambs, yearlings, and sheep produce carcasses which have low yields of boneless retail cuts. Animals of this grade consist of those not meeting the minimum requirements of Yield Grade 4 because of excess fat.
Go to the USDA Agricultural Marketing Service website for more information on commodity grades:

USDA Standards for Grades of Slaughter Lambs, Yearlings and Sheep

USDA Standards for Grades of Lamb, Yearling Mutton and Mutton Carcasses