ately large and the hide is either thick or tight and inelastic.

(2) Quality superior to that specified as minimum for the Standard grade may compensate, without limit, for conformation inferior to that specified as minimum for the Standard grade at the rate indicated in the following example: Vealers with quality equivalent to the midpoint of the Standard grade may have conformation equivalent to the midpoint of the Utility grade and remain eligible for Standard. Also, vealers with conformation at least onethird of a grade superior to that specified as minimum for the Standard grade may have quality equal to the lower limit of the upper third of the Utility grade and remain eligible for Standard.

(e) Utility. The Utility grade includes vealers whose characteristics are inferior to those specified as minimum for the Standard grade.

§ 53.124 Specifications for official U.S. standards for grades of slaughter

f

calves.

(a) Prime. (1) Calves possessing minimum qualifications for the Prime grade tend to be moderately thick muscled throughout. They are moderately wide over the back and loin, and shoulders and hips are usually moderately neat and smoothly laid in. There is a slight fullness or plumpness over the crops, loin, rump, and rounds which contributes to a rather wellrounded appearance. Prime grade calves tend to have a slightly thick fat covering over the back, loin, rump, and upper ribs. The brisket, rear flanks, and cod or udder are moderately full. Prime grade calves usually present a moderately refined appearance.

(2) To qualify for the Prime grade, slaughter calves must possess the minimum evidences of quality specified regardless of the extent to which their conformation may exceed the minimum requirements for Prime. However, quality superior to that specified as the minimum for the Prime grade may compensate, without limit, for conformation inferior to that specified as the minimum for Prime at the rate indicated in the following example: Slaughter calves which have 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.

(b) Choice. (1) Calves possessing minimum qualifications for the Choice grade tend to be slightly thick muscled throughout. They are slightly wide over the back and loin. The neck is slightly long and thin. The loin, rump, and rounds are almost flat and have little or no evidence of fullness. The shoulders and hips are moderately neat and smoothly laid in but may appear slightly prominent. There is a thin fat covering over the back, loin, and upper ribs. The brisket, rear flanks, and cod or udder tend to be slightly full. Choice grade calves are usually moderately smooth and slightly refined in appearance.

(2) To qualify for the Choice grade, slaughter calves must possess the minimum evidences of quality specified regardless of the extent to which their conformation may exceed the minimum requirements for Choice. However, quality which is superior to that specified as the minimum for the Choice grade may compensate, without limit, for conformation which is inferior to that specified as the minimum for Choice at the rate indicated in the following example: Slaughter calves which have quality equivalent to the midpoint of the Choice grade may have conformation equivalent to the midpoint of the Good grade and remain eligible for Choice.

(c) Good. (1) Calves possessing minimum requirements for the Good grade tend to be thinly muscled throughout. They are narrow over the back, loin, and rump and shallow in the twist and have a slightly sunken or hollowed-out appearance over the back, loin, and rounds. Hips and shoulders appear somewhat prominent. There is a very thin fat covering that is discernible only over the back and loin. Such calves may show the heavy bones, thick hide, prominent hips and shoulders associated with coarseness; or they may show the small bones, tight hide, and angularity denoting overrefinement.

(2) Quality superior to that specified as the minimum for the Good grade may compensate, without limit, for

conformation inferior to that specified as the minimum for Good at the rate indicated in the following example: Calves with quality equivalent to the midpoint of the Good grade may have conformation equivalent to the midpoint of the Standard grade and remain eligible for Good. Also, calves with conformation at least one-third of a grade superior to that specified as minimum for the Good grade may have quality equal to the lower limit of the upper third of the Standard grade and remain eligible for Good.

(d) Standard. (1) Calves possessing minimum requirements for the Standard grade tend to be very thinly muscled throughout and are very narrow over the back, loin, and rump, and very shallow in the twist. Hips and shoulders are very prominent and the crops, back loin, rump, and rounds present a very sunken or hollowed-out appearance. There is practically no fat on any part of the animal's body. The bones and joints are usually disproportionately large, and the hide is either thick or tight and inelastic.

(2) Quality superior to that specified as minimum for the Standard grade may compensate, without limit, for conformation inferior to that specified as minimum for the Standard grade at the rate indicated in the following example: Calves with quality equivalent to the midpoint of the Standard grade may have conformation equivalent to the midpoint of the Utility grade and remain eligible for Standard. Also, calves with conformation at least onethird of a grade superior to that specified as minimum for the Standard grade may have quality equal to the lower limit of the upper third of the Utility grade and remain eligible for Standard.

(e) Utility. The Utility grade includes slaughter calves whose characteristics are inferior to those specified as minimum for the Standard grade.

SLAUGHTER LAMBS, YEARLINGS, AND
SHEEP

§ 53.130 Market sheep.

The official standards for market sheep, developed by the United States Department of Agriculture, provide for segregation according to (a) use as

slaughter animals or feeders; (b) class or sex conditions; (c) age group; and (d) grade, which is determined by the apparent relative excellence and desirability of the individual animal for a particular use.

§ 53.131 Slaughter classes and market groups.

The classes of slaughter sheep are ram, ewe, and wether; the age groups are lambs, yearlings, and sheep. Definitions of the respective classes and age groups are as follows:

(a) Ram. A ram is an uncastrated male ovine.

(b) Ewe. A ewe is a female ovine.

(c) Wether. A male ovine castrated when young and prior to developing the secondary physical characteristics of a ram.

(d) Lamb. A lamb is an immature ovine, usually under 14 months of age, that has not cut its first pair of permanent incisor teeth.

(e) Yearling. A yearling is an ovine usually between one and two years of age, that has cut its first pair of permanent incisor teeth but has not cut the second pair.

(f) Sheep. A sheep is an ovine, usually over 24 months of age, that has cut its second pair of permanent incisor teeth.

§ 53.132 Application of standards.

(a) Grade factors. Grades of slaughter ovine are intended to be directly related to the grades of the carcasses they produce. To accomplish this, these slaughter ovine grade standards are based on factors which are directly related to the quality grades and the yield grades of ovine carcasses. The standards are written so that the quality and yield grade standards are contained in separate sections. The quality grade standards are divided into three sections applicable to slaughter lambs, slaughter yearlings, and slaughter sheep. There are four quality grades within each class-Prime, Choice, Good, and Utility for lambs and yearlings; and Choice, Good, Utility, and Cull for sheep. Also, there are five yield grades applicable to all classes of slaughter ovine, denoted by numbers 1 through 5, with Yield Grade 1

representing the highest degree of cutability.

(b) General princples. (1) The determination of the carcass grade that the slaughter animal will produce requires the exercise of well-regulated judgment. Each animal presents a different combination of the grade-determining factors. Animals frequently have characteristics associated with two or more grades. Therefore, a composite evaluation of all inherent physical characteristics is essential for accuracy in determining grade.

(2) The accurate determination of the grade of a slaughter ovine requires handling in addition to visual observation. The length and density of the fleece vary greatly with individuals and the thickness and firmness of the flesh covering of wooled ovine can only be roughly estimated without handling. The technique used in handling usually varies with the degree of precision in mind as well as the experience of the grader. Experienced graders may find one quick handling satisfactory. This usually consists of placing one open hand over the back and ribs in simultaneous motion. The thumb extends just over the backbone, while the fingers, which are held close together, cover the rib section and pressure is applied very lightly with a slight lateral and forward and backward motion. The generally accepted technique of handling ovine where time permits, and especially when noting slight differences between individuals, is to handle forward from the dock to neck with the open hand, fingers together, laid flat and with a slight lateral motion. Both hands may then be used, one on each side, in a similar manner to determine the fleshing over the shoulders, ribs, and hips. Regardless of the method, considerable experience is necessary in handling ovine to accurately determine the grade.

(c) Quality grades. (1) The quality grade of a slaughter ovine is determined by a composite evaluation of two general considerations which influence carcass excellence: Conformation and quality-fatness, maturity, and other indicators of differences in palatability of the lean flesh.

(2) Conformation refers to the general body proportions of the animal and to the ratio of meat to bone. Although primarily determined by the inherent muscular and skeletal systems, it is also influenced by the degree of fatness. However, external fat in excess of that normally left on retail cuts is not considered in evaluating conformation. The conformation descriptions included in each of the grade specifications refer to the thickness of muscling and to an overall degree of thickness and fullness of the animal. Slaughter ovine which meet the requirements for thickness of muscling specified for a grade will be considered to have conformation adequate for that grade despite the fact that, because of a lack of fatness, they may not have the overall degree of thickness and fullness described. Conformation is evaluated by averaging the conformation of the various component parts, giving special consideration to those parts of the body producing the more desirable cuts of meat-loin, hotel rack, and leg.

slaughter ovine,

(3) In grading quaity of the lean must be evaluated indirectly by considering the quantity. distribution, and type of fat or finish in relation to the maturity of the animal being graded. Limited consideration is also given to such factors as character of bone and smoothness and symmetry of body. Finish is evaluated by noting variations in the fullness and apparent thickness of the fat covering over the back, loin, ribs, and legs. A high degree of desriable finish is evidenced by a firm, smooth layer of fat which is uniformly distributed over the body.

(4) Although the market designation of slaughter ovine is usually made by classes, the quality standards are intended to apply to all classes without regard to sex condition. However, male animals which have thick heavy necks and shoulders typical of uncastrated males are discounted in grade in proportion to the extent to which these characteristics are developed. Such discounts may vary from less than half a grade in young lambs in which such characteristics are barely noticeable, to as much as two full grades in

mature rams in which such characteristics are very pronounced.

(d) Yield grades. (1) The yield grades for slaughter ovine are based on the same factors used in the official yield grade standards for ovine carcasses. These factors are as follows:

(i) Thickness of fat over ribeye. As the amount of external fat increases, the percent of retail cuts decreases and the numerical yield grade increases. Assuming no change in the other factors, each 0.15 inch change in adjusted fat thickness over the ribeye changes the yield grade by a full grade. On slaughter ovine which do not have a normal distribution of external fat, the fat thickness estimate over the ribeye may be adjusted, as necessary, to reflect unusual amounts of fat on other parts of the animal.

(ii) Percent of kidney and pelvic fat. As the amount of these fats increases, the percent of retail cuts decreases. A change of 4 percent of the carcass weight in kidney and pelvic fat changes the yield grade by a full grade.

(iii) Leg conformation grade. An increase in the conformation grade of the legs increases the percent of retail cuts. A change of two full grades in conformation of the legs changes the yield grade by approximately onethird of a yield grade.

(2) When evaluating slaughter ovine for yield grade, each of these factors can be estimated and the yield grade determined therefrom by using the equation contained in the official standards for yield grades of lamb, yearling mutton, and mutton carcasses. However, a more practical method of appraising slaughter ovine for yield grade is to use only two factors normally considered in evaluating live ovine-degree of fatness and leg conformation. In this approach, the degree of fatness largely accounts for the effects of thickness of fat over the ribeye and the percent of kidney and pelvic fat.

(3) The overall fatness of an animal can be determined best by giving particular attention to those parts on which fat is deposited at a faster-thanaverage rate. These include the back, loin, rump, flank, breast, and cod or udder. As ovine increase in fatness,

these parts become progressively fuller, thicker, and more distended in relation to the thickness and fullness of the other parts, particularly the legs. However, since an animal's thickness of muscling also affects the development of its various parts, this also needs to be considered when evaluating the degree of fatness. In thinly muscled ovine with a low degree of finish, the width of the back usually will be greater than the width through the center of the legs. Conversely, in thickly muscled ovine with a low degree of finish, the thickness through the legs will be greater than through the back and the back will be full and rounded. At an intermediate degree of fatness, ovine which are thinly muscled will be considerably wider through the back than through the leg and will be nearly flat across the back. Thickly muscled ovine that have an intermediate degree of fatness will be about the same width through the legs as through the back and the back will appear only slightly rounded. Very fat ovine will be wider through the back than through the legs, but this difference will be greater in thinly muscled ovine than in those that are thickly muscled. As ovine increase in fatness, they also become deeper bodied because of large deposits of fat in the flanks and breast and along the underline. In determining yield grade, variations in fatness are of very much greater importance than variations in conformation of the leg.

(e) Other considerations. (1) Other factors such as sex, heredity, and management also may affect the development of grade-determining characteristics in slaughter ovine. Although these factors do not lend themselves to descriptions in the standards, the use of factual information of this nature is justified in determining the grade of slaughter ovine. The ability to make proper allowances for the effects of genetic and management factors on the appearance of grade-determining characteristics must be developed through experience.

(2) Slaughter ovine qualifying for any particular grade may vary with respect to the relative development of their individual grade factors. In fact, some will qualify for a particular

grade although they have some characteristics more typical of ovine of another grade. Because it is impractical to describe the nearly infinite number of such recognizable combinations of characteristics, the standards describe only ovine which have a relatively similar development of the various quality and yield grade-determining factors and which are near the lower limits of quality or yield for the grade. However, examples of the extent to which superiority in quality-indicating characteristics may compensate for deficiencies in conformation, and vice versa, are indicated for each quality grade. In the slaughter lamb quality grade standards, the requirements are given for two maturity groups. In the yield grade standards, ovine with two levels of muscling are described and specific examples in terms of carcass characteristics also are included.

[49 FR 43036, Oct. 26, 1984]

§ 53.133 Specifications for Official U.S. Standards for Grades of Slaughter Lambs (Quality).

(a) Prime. (1) Slaughter lambs having minimum conformation requirements for the Prime grade tend to be thickly muscled throughout, and they are moderately wide and thick in relation to their length and height. The are moderately wide over the back, loin, and rump. Shoulders and hips are usually moderately smooth. The twist is moderately deep and full, and the legs are moderately large and plump. They generally present a wellrounded appearance due to a slight fullness or plumpness over the crops, loins, and rump. Relatively young lambs, under seven months of age, tend to have a moderately thin fat covering over the back, ribs, loins, and rump. In handling, the backbone and ribs are readily discernible. Older, more mature lambs have a slightly thin fat covering over the back, ribs, loin, and rump. In handling, the backbone and ribs are slightly discernible. Prime grade lambs exhibit evidences of rather high quality. The bones tend to be proportionately small, the joints tend to be smooth, and the body tends to be smooth and symmetrical.

(2) To qualify for the Prime grade, a lamb must possess the minimum quali

fications for finish regardless of the extent that its conformation may exceed the minimum requirements for Prime. However, a development of finish 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 for Prime as indicated in the following example: A lamb which has evidences of finish 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 lamb be graded Prime which has a development of conformation inferior to that specified as minimum for the Choice grade.

(b) Choice. (1) Slaughter lambs having minimum conformation requirements for the Choice grade are slightly thick muscled throughout, and they tend to be slightly wide and thick in relation to their length and height. They tend to be slightly wide over the back, loin, and rump. The shoulders and hips are usually slightly smooth but may exhibit a slight tendency toward prominence. The twist tends to be slightly deep and full, and the legs tend to be slightly thick and plump. Relatively young lambs, under seven months of age, have a thin fat covering over the back, ribs, loin, and rump. In handling, the backbone and ribs are moderately prominent. Older, mature lambs have a moderately thin fat covering over the back, ribs, loin, and rump. In handling, the backbone and ribs are slightly prominent. Choice grade lambs usually present a moderately refined appearance.

(2) A development of quality which is superior to that specified as minimum for the Choice grade may compensate, on a equal basis, for a development of conformation which is inferior to that specified as minimum for Choice as indicated in the following example: A lamb which has evidences of quality equivalent to the midpoint of the Choice grade may have conformation equivalent to the midpoint of the Good grade and remain eligible for Choice. However, in no instance may a lamb be graded Choice which has a development of conformation inferior to