ther into three separate sections applicable to carcasses from lambs, yearling mutton, and mutton. There are five quality grades-Prime, Choice, Good, Utility, and Cull-applicable to lamb, yearling mutton, and mutton carcasses, except that mutton carcasses are not eligible for Prime. There are five yield grades applicable to all classes of ovine carcasses, denoted by numbers 1 through 5, with Yield Grade 1 representing the highest degree of cutability. (3) Carcasses qualifying for any particular grade may vary with respect to the relative development of their individual grade factors, and there will be carcasses which qualify for a particular grade in which the development of some of these individual grade factors will be typical of other grades. Because it is impractical to describe the nearly limitless numbers of such recognizable combinations of characteristics, the standards for each quality and yield grade describe only carcasses which have a relatively similar development of individual factors and which are also representative of the lower limits of each grade. In the quality grade standards, examples of the extent to which superiority in quality may compensate for deficiencies in conformation, and vice versa, are indicated for each grade. In the Prime and Choice grades certain minimum requirements for external fat covering are also indicated. (b) Quality grades. (1) The quality grade of an ovine carcass is based on separate evaluations of two general considerations: The quality or the palatabilityindicating characteristics of the lean and the conformation of the carcass. (2) Conformation is the manner of formation of the carcass with particular reference to the relative development of the muscular and skeletal systems, although it is also influenced to some extent, by the quantity and distribution of external finish. The conformation of a carcass is evaluated by averaging the conformation of its various component parts, giving consideration not only to the proportion that each cut is of the carcass weight but also to the general desirability of each cut as compared with other cuts. Superior conformation implies a high proportion of edible meat to bone and a high proportion of the weight of the carcass in the more demanded cuts and is reflected in carcasses which are very wide and thick in relation to their length and which have a very plump and full and well-rounded appearance. Inferior conformation implies a low proportion of edible meat to bone and a low proportion of the weight of the carcass in the more demanded cuts and is reflected in carcasses which are very narrow in relation to their length and which have a very angular, thin and sunken appearance. External fat in excess of that normally left on retail cuts is not considered in evaluating conformation. (3) The quality of the lean flesh is best evaluated by consideration of its texture, firmness, and marbling, as observed in a cut surface, in relation to the apparent maturity of the animal from which the carcass was produced. However, in grading carcasses direct observation of these characteristics is not possible. Therefore, the quality of the lean is evaluated indirectly by giving equal consideration to: The quantity of fat intermingled within the lean between the ribs called "feathering," the streaking of fat within and upon the inside flank muscles, and the firmness of the fat and lean-all in relation to the apparent evidence of maturity. (4) The ovine quality standards are intended to cover the full range of maturity within which ovines are marketed. The standards for Prime, Choice, and Good grades of lamb specify two general levels of development of the qualityindicating characteristics described in this section, dependent upon the apparent evidences of maturity attained by the lamb at the time of slaughter. The quality standards for Utility and Cull grades of lamb and for each grade of yearling mutton and mutton specify only one general level of development of the quality-indicating characteristics described, and these characteristics apply only to carcasses which are typical in maturity for their class. In order to qualify for a specific grade, yearling mutton or mutton carcasses with evidence of more advanced maturity than typical for their class are required to have a slightly greater development of these characteristics than described in the standards. Conversely, such carcasses with evidence of less maturity than typical for their class may qualify for a given grade with a slightly lesser development of these characteristics. (5) The quality standards are intended to apply to all ovine carcasses without regard to the apparent sex condition of the animal at time of slaughter. However, carcasses from males which have thick, heavy necks and shoulders typical of uncastrated males are discounted in quality grade in accord with the extent to which these characteristics are developed. Such discounts may vary from less than one-half grade in carcasses from young lambs in which such characteristics are barely noticeable to as much as two full grades in carcasses from mature rams in which such characteristics are very pronounced. (6) The quality standards for lamb, yearling mutton, and mutton carcasses contained in this subpart together provide for grading carcasses within the full range of maturity of the ovine species. Although the grade standards for this full range of maturity are contained in three separate standards, it is the intent that the three standards be considered as a continuous series. Therefore, in determining the grade of a carcass which has a degree of maturity that is not typical of that specified in one of the three standards, it is necessary to interpolate between the standard for the kind of carcass (lamb, yearling mutton, or mutton) being graded and the standard for the kind of carcass which is most closely adjacent to it in maturity. (c) Yield grades. (1) The yield grade of an ovine carcass is determined by considering three characteristics: The amount of external fat, the amount of kidney and pelvic fat, and the conformation grade of the legs. (2) The amount of external fat for carcasses with a normal distribution of this fat is evaluated in terms of its actual thickness over the center of the ribeye muscle and is measured perpendicular to the outside surface between the 12th and 13th ribs. On intact carcasses fat thickness is measured by probing. This measurement may be adjusted, as necessary, to reflect unusual amounts of fat on other parts of the carcass. In determining the amount of this adjustment, if any, particular attention is given to the amount of external fat on those parts where fat is deposited at a faster-thanaverage rate, particularly the rump, outside of the shoulders, breast, flank, and cod or udder. Thus, in a carcass which is fatter over these other parts than is normally associated with the actual fat thickness over the ribeye, the measure ment is adjusted upward. Conversely, in a carcass which has less fat over these other parts than is normally associated with the actual fat thickness over the ribeye, the measurement is adjusted downward. In many carcasses no such adjustment is necessary; however, an adjustment in the thickness of fat measurement of 0.05 or 0.10 inch is not uncommon. In some carcasses a greater adjustment may be necessary. As a guide in making these adjustments, the standards for each yield grade include an additional related measurement-body wall thickness, which is measured 5 inches laterally from the middle of the backbone between the 12th and 13th ribs. As the amount of external fat increases, the percent of retail cuts decreases each 0.05 inch change in adjusted fat thickness over the ribeye changes the yield grade by one-third of a grade. (3) The amount of kidney and pelvic fat considered in determining the yield grade includes the kidney knob (kidney and surrounding fat) and the lumbar and pelvic fat in the loin and leg which are removed in making closely trimmed retail cuts. The amount of these fats is evaluated subjectively and expressed as a percent of the carcass weight. As the amount of kidney and pelvic fat increases, the percent of retail cuts decreases a change of 1 percent of the carcass weight in kidney and pelvic fat changes the yield grade by one-fourth of a grade. (4) The conformation grade of the legs is evaluated as described in the quality standards. The evaluation is made in terms of thirds of grades and coded using 15 for high Prime and 1 for low Cull. An increase in the conformation grade of the legs increases the percent of retail cutsa change of one-third of a grade changes the yield grade by 5 percent of a grade. (5) The yield grade descriptions are defined primarily in terms of carcasses. However, the yield grade standards also are applicable to the grading of sides, foresaddles, hindsaddles, forequarters, and hindquarters, and hotel racks, loins, and combinations of regular or trimmed wholesale cuts which include either a hotel rack or a loin. (6) The standards include an equation for determining yield grade. The application of this equation usually results in a fractional grade. However, in normal grading operations any fractional part of a yield grade is dropped. For example, if the computation results in a yield grade of 3.9, the final yield grade is 3it is not rounded to 4. (7) The yield grade standards for each of the first four yield grades list characteristics of a carcass with descriptions of the amount of external fat normally present on various parts of the carcass. These descriptions are not specific requirements-they are included only as illustrations of carcasses which are near the borderline between grades. For example, the characteristics listed for Yield Grade 1 represent a carcass which is near the borderline of Yield Grade 1 and Yield Grade 2., These descriptions facilitate the subjective determination of the yield grade without making detailed measurements and computations. The yield grade for most ovine carcasses can be determined accurately on the basis of a visual appraisal. [34 F.R. 240, Jan. 8, 1969] § 53.116 Specifications for official U.S. standards for grades of lamb carcasses (quality).' (a) Prime. (1) Lamb carcasses possessing minimum qualifications for the Prime grade 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. (2) Requirements for quantities of interior fats and for firmness of lean and fat vary with changes in maturity. Carcasses from young lambs have moderately narrow, slightly flat rib bones; moderately red and moist and porous break joints; and a slightly dark pink color of inside flank muscles. Such carcasses have a modest amount of feathering between the ribs and a small quantity of fat streaking within and upon the inside flank muscles. Their lean flesh and exterior finish tend to be firm, and their flanks tend to be moderately full and firm. (3) Carcasses from more mature lambs have slightly wide, moderately flat rib bones; slightly red but slightly dry and hard break joints; and a light red color of inside flank muscles. Such carcasses have a moderate amount of feathering between the ribs and a modest amount of fat streaking within and upon the inside flank muscles. Their lean flesh and external finish are firm, 134 FR 242, Jan. 8, 1969. and their flanks are moderately full and firm. (4) Regardless of the extent to which other grade factors may exceed the minimum requirements for Prime, to be eligible for Prime a carcass must have at least a very thin covering of external fat over the top of the shoulders and the outsides of the upper parts of the legs, and the back must have at least a thin covering of fat, that is, the muscles of the back may be no more then plainly visible through the fat. In addition, a carcass must have a composite development of quality-indicating factors equivalent to that specified as minimum for Prime to be eligible for that 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 as indicated in the following example: A carcass which has evidence of quality equivalent to the midpoint of the Prime grade may have conformation equivalent to the midpoint of the Choice grade and remain eligible for Prime. However, in no instance may a carcass be graded Prime which has a development of conformation inferior to that specified as minimum for the Choice grade. (b) Choice. (1) Lamb carcasses possessing minimum qualifications for the Choice grade 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. (2) Requirements for quantities of interior fats and for firmness of lean and fat vary with changes in maturity. Carcasses from young lambs have moderately narrow, slightly flat rib bones; moderately red and moist and porous break joints; and a moderately dark pink color of inside flank muscles. Such carcasses have a slight amount of feathering between the ribs and traces of fat streaking within and upon the inside flank muscles. Their lean flesh and exterior finish tend to be moderately firm, and their flanks tend to be slightly full and firm. (3) Carcasses from more mature lambs have slightly wide, moderately flat rib bones; slightly red but slightly dry and hard break joints; and a moderately light red color of inside flank muscles. Such carcasses have a small amount of feathering between the ribs and a slight amount of fat streaking within and upon the inside flank muscles. Their lean flesh and external finish are moderately firm, and their flanks are slightly full and firm. (4) Regardless of the extent to which other grade factors may exceed the minimum requirements for Choice, to be eligible for Choice a carcass must have at least a very thin covering of external fat over the top of the shoulders and the outsides of the upper parts of the legs, and the back must have at least a thin covering of fat, that is, the muscles of of the back may be no more than plainly visible through the fat. (5) A carcass which has conformation equivalent to at least the mid-point of the Choice grade may have evidence of quality equivalent to the minimum for the upper one-third of the Good grade and remain eligible for Choice. Also, 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 that specified as minimum for Choice as indicated in the following example: A carcass which has evidence of quality equivalent to the mid-point of the Choice grade may have conformation equivalent to the mid-point of the Good grade and remain eligible for Choice. However, in no instance may a carcass be graded Choice which has a development of conformation inferior to that specified as minimum for the Good grade. (c) Good. (1) Lamb carcasses possessing minimum qualifications for the Good grade are moderately narrow in relation to their length and have slightly thin, tapering legs, and slightly narrow and thin backs and shoulders. (2) Requirements for quantities of interior fats and for firmness of lean and fat vary with changes in maturity. Carcasses from young lambs have moderately narrow, slightly flat rib bones; moderately red and moist and porous break joints; and a dark pink color of inside flank muscles. Such carcasses have traces of feathering between the ribs but practically no fat streaking within and upon the inside flank muscles. Their lean flesh and exterior finish are slightly firm, and their flanks are slightly thin and soft. (3) Carcasses from more mature lambs have slightly wide, moderately flat rib bones; slightly red but slightly dry and hard break joints; and a slightly dark red color of inside flank muscles. Such carcasses have a slight amount of feathering between the ribs and traces of fat streaking within and upon the inside flank muscles. Their lean flesh and external finish tend to be moderately firm, and their flanks tend to be slightly full and firm. (4) A carcass which has conformation equivalent to at least the mid-point of the Good grade may have evidence of quality equivalent to the minimum for the upper one-third of the Utility grade and remain eligible for Good. Also, a development of quality which is superior to that specified as minimum for the Good grade may compensate for a development of conformation which is inferior to that specified as minimum for Good on the basis of one-half grade of superior quality for one-third grade of deficient conformation as indicated in the following example: A carcass which has evidence of quality equivalent to the mid-point of the Good grade may have conformation equivalent to the minimum for the upper one-third of the Utility grade and remain eligible for Good. However, in no instance may a carcass be graded Good which has a development of conformation inferior to that specified as minimum for the Utility grade. (d) Utility. (1) Lamb carcasses possessing minimum qualifications for the Utility grade are very angular and very narrow in relation to their length and have thin, slightly concave legs; very narrow and sunken backs; and narrow, sharp shoulders. Hips and shoulder joints are plainly visible. (2) Although evidences of quality vary slightly with changes in maturity the differences are so small as to make their separate descriptions impractical There is practically no feathering between the ribs and no fat streaking in the inside flank muscles. The lean in the inside flank muscles and between the ribs is a dark red in color. Their lean flesh and external finish are soft, and the flanks are soft and slightly watery. (3) A carcass which has conformation equivalent to at least the mild-point of the Utility grade may have evidence of quality equivalent to the minimum for the upper one-third of the Cull grade and remain eligible for Utility. Also, a development of quality which is superior to that specified as minimum for the Utility grade may compensate for a development of conformation which is in ferior to that specified as minimum for Utility on the basis of one-half grade of superior quality for one-third grade of deficient conformation as indicated in the following example: A carcass which has evidence of quality equivalent to the mid-point of the Utility grade may have conformation equivalent to the minimum for the upper one-third of the Cull grade and remain eligible for Utility. (e) Cull. Typical Cull grade lamb carcasses are extremely angular, extremely narrow in relation to their length, and extremely thin-fleshed throughout. Legs are extremely thin and concave, backs are extremely sunken and thin, and shoulders are very thin and sharp. Hips and shoulder joints, as well as ribs and bones of the spinal column, are clearly outlined, and the flesh is soft and watery and a very dark red in color. § 53.117 Specifications for official U.S. standards for grades of yearling mutton carcasses (quality).1 (a) Prime. (1) Yearling mutton carcasses possessing minimum qualifications for the Prime grade 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. They have slightly abundant feathering between the ribs, a moderate amount of fat streaking within and upon the inside flank muscles, and a slightly dark red color of inside flank muscles. Their lean flesh and external finish tend to be very firm, and their flanks tend to be full and firm. (2) Regardless of the extent to which other grade factors may exceed the minimum requirements for Prime, to be eligible for Prime a carcass must have at least a very thin covering of external fat over the top of the shoulders and the outsides of the upper parts of the legs, and the back must have at least a thin covering of fat, that is, the muscles of the back may be no more than plainly visible through the fat. In addition, a carcass must have a composite development of quality-indicating factors equivalent to that specified as minimum for Prime to be eligible for that 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 134 FR 242, Jan. 8, 1969. 41 conformation which is inferior to that specified as minimum for Prime as indicated in the following example: A carcass which has evidence of quality equivalent to the mid-point of the Prime grade may have conformation equivalent to the mid-point of the Choice grade and remain eligible for Prime. However, in no instance may a carcass be graded Prime which has a development of conformation inferior to that specified as minimum for the Choice grade. (3) Yearling mutton carcasses which are otherwise eligible for the Prime grade but which have excessive quantities of combined external and kidney and pelvic fat are not eligible for Prime. (b) Choice. (1) Yearling mutton carcasses possessing minimum qualifications for the Choice grade 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. They have a modest amount of feathering between the ribs, a small amount of fat streaking within and upon the inside flank muscles, and a color of inside flank muscles which tends to be moderately dark red. Their lean flesh and external finish tend to be firm, and their flanks tend to be moderately full and firm. (2) Regardless of the extent to which other grade factors may exceed the minimum requirements for Choice, to be eligible for Choice a carcass must have at least a very thin covering of external fat over the top of the shoulders and the outsides of the upper parts of the legs, and the back must have at least a thin covering of fat, that is, the muscles of the back may be no more than plainly visible through the fat. (3) A carcass which has conformation equivalent to at least the mid-point of the Choice grade may have evidence of quality equivalent to the minimum of the upper one-third of the Good grade and remain eligible for Choice. Also, 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 that specified as minimum for Choice as indicated in the following example: A carcass which has evidence of quality equivalent to the mid-point of the Choice grade may have conformation equivalent to the mid-point of the Good grade and remain eligible for Choice. However, in no in |