Imagini ale paginilor
PDF
ePub

Carcasses are usually moderately wellbalanced and moderately uniform in fleshing and finish. There are moderate quantities of interior fat in the pelvic area, a slightly thin but moderately extensive layer of fat lining the inside surface of the ribs, and a slightly small quantity of feathering, or fat intermingled with the lean between the ribs. The lean is firm. Both exterior and interior fats are firm, white, and of excellent quality. Carcasses with back fat thickness qualifying them for the fatter one-half of the U. S. No. 1 grade but with thin muscling in the major cuts, uneven fleshing and finish, or thick and uneven bellies shall be graded U. S. No. 2. Carcasses with back fat thickness qualifying them for the thinner one-half of the U. S. No. 1 grade but with only a moderately thin and incomplete rib lining, a moderately small quantity of feathering, slightly thin bellies with moderately thin belly pockets, and moderately soft lean and fat shall be graded Medium.

(b) U. S. No. 2 grade. U. S. No. 2 grade sow carcasses have a higher degree of finish than the minimum required to produce pork cuts of acceptable palatability. Meatiness and yield of lean cuts from carcass weight are slightly low. Yield of fat cuts is slightly high. The ratio of total lean and fat to bone is moderately high. Carcasses with the minimum finish required for U. S. No. 2 grade are slightly short and moderately wide in relation to weight. The back and loins are full and thick and are especially full near the edges. Hams are usually thick and plump and are moderately full in the lower part toward the hock. Bellies are slightly short, moderately thick, and rather uniform in thickness with a moderately thick belly pocket. Shoulders are moderately thick and full. Carcasses are usually well-balanced and uniform in fleshing and finish.

There

are slightly large quantities of interior fat in the pelvic area, a slightly thick and rather extensive layer of fat lining the inside surface of the ribs, and moderate feathering. The lean is firm. Both exterior and interior fats are firm, white, and of excellent quality. Carcasses with back fat thickness qualifying them for the fatter one-half of the U. S. No. 2 grade but with thin muscling in the major cuts, uneven fleshing and finish, or very thick and uneven bellies shall be graded U. S. No. 3. Carcasses

with back fat thickness qualifying them for the thinner one-half of the U. S. No. 2 grade but with thick muscling in the major cuts, well-balanced fleshing and uniform finish, and slightly thick bellies shall be graded U. S. No. 1.

U. S. No. 3

(c) U. S. No. 3 grade. grade sow carcasses have a decidedly higher degree of finish than the minimum required to produce pork cuts of acceptable palatability. Meatiness and yield of lean cuts from carcass weight are low. Yield of fat cuts is high. The ratio of total lean and fat to bone is high. Carcasses with the minimum finish required for U. S. No. 3 grade are short and wide in relation to weight. The back and loins are very full and thick and are decidedly full at the edges. Hams are usually very thick and plump and are full in the lower part toward the hock due to a thick fat covering. Bellies are short and thick and uniform in thickness with a thick belly pocket. Shoulders are thick and full. Carcasses are usually well-balanced and uniform in fleshing and finish. There are large quantities of interior fat in the pelvic area, a moderately thick and extensive layer of fat lining the inside surface of the ribs, and slightly abundant feathering. The lean is firm. Both exterior and interior fats are firm, white, and of excellent quality. Carcasses with back fat thickness indicative of nearly minimum finish for the U. S. No. 3 grade but with thick muscling in the major cuts, well-balanced fleshing and uniform finish, and moderately thick bellies shall be graded U. S. No. 2.

(d) Medium grade. Medium grade Sow carcasses have a lower degree of finish than the minimum required to produce pork cuts of acceptable palatability. Yield of lean cuts from carcass weight is moderately high. Yield of fat cuts is moderately low. The ratio of total lean and fat to bone is moderately low.

Carcasses with the minimum finish required for Medium grade are long and rather narrow in relation to weight. The back and loins are rather thin, lack fullness, and slope away from the center. Hams are usually slightly thin, lack plumpness, and taper toward the hock Bellies are long and moderately thin and are somewhat uneven in thickness with

a thin belly pocket. Shoulders are moderately thin and flat. Carcasses tend to be uneven and lack uniformity of fleshing and finish. There are slightly small quantities of interior fat in the pelvic area, a thin and incomplete layer of fat lining the inside surface of the ribs, and only a small quantity of feathering. The lean is moderately soft with little evidence of marbling. Both exterior and interior fats are moderately soft, white to creamy white, and of moderately low quality. Carcasses with back fat thickness qualifying them for the fatter one-half of the Medium grade that are firm and have slightly thick bellies and belly pockets, a slightly thin but moderately extensive rib lining, and a slightly small quantity of feathering I shall be graded U. S. No. 1. Carcasses with back fat thickness qualifying them 1 for the thinner one-half of the Medium Igrade but with little or no rib lining and feathering, thin bellies and very thin belly pockets, and soft lean and fat shall be graded Cull.

The

(e) Cull grade. Cull grade sow carcasses have a decidedly lower degree of finish than the minimum required to produce pork cuts of acceptable palatability. Yield of lean cuts from carcass weight is high. Yield of fat cuts is low. The ratio of total lean and fat to bone is low. Carcasses with the degree of finish typical of the Cull grade are long and narrow in relation to weight. back and loins are thin and decidedly lacking in fullness with a definite slope toward the sides. Hams are usually thin and flat and taper toward the hock. Bellies are very long and thin and are uneven in thickness with a very thin belly pocket. Shoulders are thin and flat. Carcasses tend to be uneven and lack uniformity of fleshing and finish. There are only small quantities of interior fat in the pelvic area, little or no fat lining the inside surface of the ribs, and scant feathering. The lean is soft and watery with very little evidence of marbling. Both exterior and interior fats are soft, creamy white to white, and of low quality. Carcasses with back fat thickness indicative of nearly maximum finish for the Cull grade that are only moderately soft and have moderately

[blocks in formation]

The official standards for swine developed by the U.S. Department of Agriculture provide for segregation first according to intended use-slaughter or feeder-then as to class, as determined by sex condition, and then as to grade, which is determined by the apparent relative excellence and desirability of the animal for a particular use. Differentiation between slaughter and feeder swine is based solely on their intended use rather than on specific identifiable characteristics of the swine. Slaughter swine are those which are intended for slaughter immediately or in the near future. Feeder swine are those which are intended for slaughter after a period of feeding.

[30 F.R. 16253, Dec. 30, 1965]

§ 53.151 Slaughter and feeder swine classes.

There are five classes of slaughter and feeder swine. Definitions of the respective classes are as follows:

(a) Barrow. A barrow is a male swine castrated when young and before development of the secondary physical characteristics of a boar.

(b) Gilt. A gilt is a young female swine that has not produced young and has not reached an advanced stage of pregnancy.

(c) Sow. A sow is a mature female swine that usually shows evidence of having reproduced or having reached an advanced stage of pregnancy.

(d) Boar. A boar is an uncastrated male swine.

(e) Stag. A stag is a male swine castrated after development or beginning of development of the secondary physical characteristics of a boar. Typical stags are somewhat coarse and lack balance the head and shoulders are more fully developed than the hindquarter parts, bones and joints are large, the skin is thick and rough, and the hair is coarse. [30 F.R. 16253, Dec. 30, 1965]

§ 53.152

Application of standards for grades of slaughter barrows and gilts.

(3) Grades of slaughter barrows and gilts are intended to be directly related to the grades of the carcasses they produce. To accomplish this, the slaughter barrow and gilt grades are predicated on the same two geners. cccstdersäcns that provide the basis for the grades of barrow and git carcasses: (1) Quality of the lean, and 2) expected combined carcass yields of the four lean curs Cham, loin, pienie shoulder, and Boston butt.

b With respect to quality, two genersi levels are considered: One for barrows and gilts with characteristics which indicate that the carcass lean vill have acceptable quality and acceptable beily thickness and one for barrows and gilts with characteristics which indicate that the carcass lean will have unacceptable quailty and, or the belly will be of un

acceptable thickness. Since carcass in

dices of lean quality are not directly evident in barrows and gits, some other factors in which differences can be noted must be used to evaluate quality. There fore, the amount and distribution of external înisa, irmness of fat, and firmness of lean are used as qualityindtesting factors.

(c) Barrows and gilts with characteristics which indicate that the carcass lean will have an inacceptable level of quailty and or the beily will be of unacceptable thickness are graded U.S. Utility. Also graded J.S. Jtility regardless of their development of other quality-indicating characteristics are sisugiter barrows and pits with indications that their carcasses will be sort and nly.

(d) Four grades S. No. 1. J.S. No. 2. T.S. No. 3, and T.S. No. are provided for barrows and gilts with characteristics vmen indicate that the carcass lean vill have an acceptable levei of quality. These grades are based entrely on the expected combined carcass vieics of the four lean cuts.

e Average backrat thickness in reisdon to carcass lengra or ive weight is used as a guide to expected veids of the

four lean cuts in these standards. In grading barrows and gilts, these factors normally are appraised visually; live weight is the only one that can be readily determined in the live animal. The average back as thickness appraisal includes consideration of the distribution of fat on other parts of the animal in addition to those points on the back where it is measured on the carcass.

(2) Barrows and gilts will produce carcasses that vary in yields of four lean cuts because of variations in their degree of famess expressed as average thickdess of backas, and in their degree of

pickness of muscitng in relazca 20 skeletal size. Since many slaughter swine have a normal development of muscilag for their degree of fatcess. in determining der grade the average thickness of backfat and carcass lengra or tre weight are the only factors considered. These relationships are Mustrated in Figure I for barrows and plus vagining 270 to 350 pounds that vill produce carcasses 27 to 36 menes Long. For siaughter swine of other lengths or weights. average backfat thickness requirements for the various grades can be determined by an extension of the ines in this igure. The degree of muscling specified for each of the four grades decreases progressively from the

S. No. 1 grade through the CS. No. 4 grade. This reflects the fact that among barrows and plts of the same weight, the fatter animais normally have a lesser degree of musciing. For purposes of these standards six degrees of muscling are recognized: Very thick, thick, moderately thick, slightly chin, thin, and very thin. These degrees are intended to cover the entire range of muscitng present among siaughter swine. The degrees specified as wypical for barrows and gilts at the minimum of the 7.3. No. 1. T.S. No. 2, J.S. No. 3, and 7.S. No. 4 grades are, respectively: Thies, moderately thick, signtly hun, and hin. For animais 187ing a development of musciing which is ifferent from that normally associated with their degree of fatness, the average backing thickness-carcass length or 7erage sexia mexness-ive weight re lationships for ne various grades are

ferent from those shown in Figure L

Consideration is given such unusual developments of muscling as follows: In each grade, superior muscling is permitted to compensate for greater fatness at the rate of one full degree of superior muscling for a one-tenth inch increase in average backfat. Except for the U.S. No. 1 grade, the reverse type of compensation is also permitted and at the same rate; one-tenth inch less fat compensates for a

full degree of inferior muscling. In the U.S. No. 1 grade, this type of compensation is limited to one full degree of inferior muscling; barrows and gilts which have less than moderately thick muscling but which otherwise qualify for the U.S. No. 1 grade are graded U.S. No. 2.

(g) In no case, however, may variations-from-normal muscling alter the final grade more than one full grade.

RELATIONSHIP BETWEEN AVERAGE THICKNESS OF BACKFAT, WEIGHT OR CARCASS LENGTH, AND GRADE FOR BARROWS AND GILTS WITH MUSCLING TYPICAL OF THEIR DEGREE OF FATNESS.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

An average of three measurements including the skin made opposite the first and last ribs and the last lumbar vertebra. It also reflects adjustment, as appropriate, to compensate for variations fat distribution.

[ocr errors]

from

normal

2/ Carcass length is measured from the anterior point of the aitch bone to the anterior edge of the first rib.

Figure I

(h) In evaluating barrows and gilts for fatness and muscling, variations in the degree of fatness have a greater effect on the yield of the lean cuts than do variations in muscling. The fatness and muscling evaluations can best be made simultaneously. This is accomplished by considering the development of the various parts based on an understanding

of how the appearance of each part is affected by variations in muscling and fatness. While the muscling of most swine develops uniformly, fat is normally deposited at a considerably faster rate on some parts than on others. Therefore, muscling can be appraised best by giving primary consideration to the parts least affected by fatness, such as the

ham. Differences in thickness and fullness of the ham-with appropriate adjustments for the effects of variations in fatness-are the best indicators of the overall degree of muscling in slaughter barrows and gilts. Conversely, the overall fatness of barrows and gilts can be determined best by observing those parts on which fat is deposited at a faster-thanaverage rate. These include the edge of the loin, the rear flank, the shoulder, the jowls, and the belly. As swine increase in fatness, these parts appear progressively fuller, thicker, and more distended in relation to the thicknes and fullness of the other parts, especially the thickness through the hams. In thinly muscled swine with a low degree of fatness, the width of the back usually will be greater than the width through the center of the hams. The back on either side of the backbone will appear sloping and flat. Conversely, in thickly muscled swine with a similar degree of fatness, the thickness through the hams will be greater than through the back and the back will appear full and well rounded. Very fat swine will be wider through the back than through the hams, but this difference will be greater in thinly muscled swine than in those that are thickly muscled. Such swine with thin muscling also will have a distinct break from the back into the sides, while those with thick muscling will be nearly flat on top but will have a less distinct break into the sides. As slaughter swine increase in fatness, they also become deeper bodied because of deposits of fat in the flanks and along the underline. The bulge of the flanks, best observed when the animal walks, and the thickness and fullness of the jowls are other indications of fatness.

(i) Barrows and gilts qualifying for the U.S. No. 1, U.S. No. 2, U.S. No. 3, or U.S. No. 4 grades may vary with respect to the relative development of the individual grade factors. In fact, some will qualify for a particular grade although they have some characteristics more nearly typical of another grade. Because it is impractical to describe the nearly infinite number of such recognizable combinations of characteristics, the

standards for each grade describe only barrows and gilts whose expected carcass yield of the four lean cuts is at the lower limit of each grade and which have a development of muscling that is normal for such swine.

(j) Other factors such as heredity and management also may affect the development of the grade-determining characteristics in slaughter swine. Although these factors do not lend themselves to description in the standards, the use of factual information of this nature is justifiable in determining the grade of barrows and gilts. 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.

[33 F.R. 9249, June 22, 1968]

§ 53.153 Specifications for official U.S. standards for grades of slaughter barrows and gilts.

(a) U.S. No. 1. Barrows and gilts in this grade will produce carcasses with acceptable lean quality and acceptable belly thickness and a high percentage of lean cuts. Swine near the borderline between the U.S. No. 1 and U.S. No. 2 grades are thickly muscled in the hams, loins, and shoulders. The width through the hams is nearly equal to the width through the shoulders and both are wider than the back. The back is slightly full, is well rounded, and blends smoothly into the sides. The sides are moderately long and smooth. The rear flank is slightly full and its depth is less than the depth of the fore flank. The jowls are firm and slightly thick and full. A development of muscling superior to that specified as minimum for the U.S. No. 1 grade may compensate for a development of fatness which is greater than that indicated in Figure I as maximum for the U.S. No. 1 grade at the rate of one full degree of muscling for one-tenth of an inch greater thickness of backfat. For example, a barrow or gilt with very thick muscling may have one-tenth of an inch more backfat than that indicated in Figure I as maximum for this grade and remain eligible for the U.S. No. 1 grade. The reverse type of compensation is also permitted at the

« ÎnapoiContinuă »