Yearling Mutton Grades and Standards

a. Yearling mutton carcasses having minimum conformation qualifications for the Prime grade tend to be thickly muscled throughout, are moderately wide and thick in relation to their length and have moderately plump and full legs, moderately wide and thick backs, and moderately thick and full shoulders.

b. Minimum requirements for fat streakings within and upon the inside flank muscles are specified for one maturity group which covers the entire range of maturity within the yearling mutton class. Typical yearling mutton carcasses have moderately wide rib bones which tend to be flat; and a slightly dark red color of inside flank muscles. The minimum degree of flank fat streakings required for such carcasses increases with advancing maturity throughout this group from minimum moderate to maximum moderate (see Figure 1 - pdf).

c. Regardless of the extent to which the conformation of a carcass may exceed the minimum requirements for Prime, a carcass must have minimum Prime quality to be eligible for the Prime grade. However, a development of quality which is superior to that specified as minimum for the Prime grade may compensate, on an equal basis, for a development of conformation which is inferior to that specified as minimum for Prime

a. Yearling mutton carcasses having minimum conformation qualifications for the Choice grade are slightly thick muscled throughout, they tend to be slightly wide and thick in relation to their length and tend to have slightly plump and full legs, slightly wide and thick backs, and slightly thick and full shoulders.

b. Minimum requirements for fat streakings within and upon the inside flank muscles are specified for one maturity group which covers the entire range of maturity within the yearling mutton class. Typical yearling mutton carcasses have moderately wide rib bones which tend to be flat; and a color of inside flank muscles which tends to be moderately dark red. The minimum degree of flank fat streakings required for such carcasses increases with advancing maturity throughout this group from minimum small to maximum small (see Figure 1 - pdf).

c. A development of quality which is superior to that specified as minimum for the Choice grade may compensate, on an equal basis, for a development of conformation which is inferior to the specified as minimum for Choice

a. Yearling mutton carcasses having minimum conformation qualifications for the Good grade are slightly thin muscled throughout, are moderately narrow in relation to their length and have slightly thin, tapering legs, and slightly narrow and thin backs and shoulders. 

b. Minimum requirements for fat streakings within and upon the inside flank muscles are specified for one maturity group which covers the entire range of maturity within the yearling mutton class. Typical yearling mutton carcasses have moderately wide rib bones which tend to be flat; and a moderately dark red color of inside flank muscles. The minimum degree of flank fat streakings required for such carcasses increases with advancing maturity throughout this group from minimum slight to maximum slight (see Figure 1 - pdf).

c. A development of quality which is superior to that specified as minimum for the Good grade may compensate, on an equal basis, for a development of conformation which is inferior to that specified as minimum for Good.

 

a. A carcass in Yield Grade 1, which is near the borderline with Yield Grade 2, usually has only a thin layer of external fat over the back and loin and slight deposits of fat in the flanks and cod or udder. There is usually a very thin layer of fat over the top of the shoulders and the outside of the legs. Muscles are usually plainly visible on most areas of the carcass.

b. A carcass in Yield Grade 1 with the maximum amount of fat allowed would have an adjusted fat thickness of 0.15 inch. Such a carcass with normal fat distribution and weighing 55 pounds would also have a body wall thickness of about 0.75 inch, and one weighing 75 pounds would have a body wall thickness of about 0.85 inch.

a. A carcass in Yield Grade 2, which is near the borderline with Yield Grade 3, usually has a slightly thin layer of fat over the back and loin and the muscles of the back are not visible. The top of the shoulders and the outside of the legs have a thin covering of fat and the muscles are slightly visible. There are usually small deposits of fat in the flanks and cod or udder.

b. A carcass in Yield Grade 2 with the maximum amount of fat allowed would have an adjusted fat thickness of 0.25 inch. Such a carcass with normal fat distribution and weighing 55 pounds would also have a body wall thickness of about 0.90 inch, and one weighing 75 pounds would have a body wall thickness of about 1.00 inch.

a. A carcass in Yield Grade 3, which is near the borderline with Yield Grade 4, usually has a moderately thick covering of fat over the back. The top of the shoulders are completely covered, and the legs are nearly completely covered, although the muscles on the outside of the lower legs are visible. There usually are slightly large deposits of fat in the flanks and cod or udder.

b. A carcass in Yield Grade 3 with the maximum amount of fat allowed would have an adjusted fat thickness of 0.35 inch. Such a carcass with normal fat distribution and weighing 55 pounds would also have a body wall thickness of about 1.05 inches, and one weighing 75 pounds would have a body wall thickness of about 1.15 inches.

a. A carcass in Yield Grade 4, which is near the borderline with Yield Grade 5, usually is completely covered with fat. There usually is a very thick covering of fat over the back and a slightly thick covering over the shoulders and legs. There usually are large deposits of fat in the flanks and cod or udder.

b. A carcass in Yield Grade 4 with the maximum amount of fat allowed would have an adjusted fat thickness of 0.45 inch. Such a carcass with normal fat distribution and weighing 55 pounds would also have a body wall thickness of about 1.20 inches, and one weighing 75 pounds would have a body wall thickness of about 1.30 inches.