Basis For Grading Lamb And Mutton

The act of grading naturally follows that of classifying and is a continuation of the same analytical process In the present case, the whole commodity has been divided into two major groups—lamb and mutton, the latter being further subdivided into yearling mutton and mature mutton. These groups are frequently called classes, but are really age selections. The divisions are based upon the age of the animals which produced the meat.

Grading is a further subdivision in which groupings are made within rather narrow and well-defined limits. In determining these groups conformation, finish and quality are the prime factors, and each group should be highly uniform in all details.

Weight has a great influence on price but it is not a grade factor.

Because of extremes of conformation, finish and quality and resultant wide variations in value of the two groups, no scheme of grading which does not recognize the importance of relative values can fit into and serve the needs of the industry.

Generally there are slight variations in conformation, finish and quality between different carcasses of the same grade. Furthermore, it is possible for two carcasses to be of equal excellence with respect to two characteristics and yet be placed in different grades because of variation in the third. Quality is the most important of the three fundamentals, yet quality is almost wholly dependent upon the degrees of conformation and finish. In fact, conformation and finish are to a great extent prerequisites of quality. A meat grader, in determining quality or grade, first considers the conformation and finish. There are other factors which indicate quality, such as color, grain, and texture of the flesh, and age of the animal as indicated by characteristics of the bones. Because of trade preferences, size and weight of carcasses frequently influence the prices, but weight has no significance from the standpoint of grade.

Inasmuch as no two carcasses are exactly alike, it necessarily follows that there must be a range of quality within each grade, but in no case is the range of quality wide. Variations may be noted in conformation, finish, or quality or there may be slight deficiencies in some carcasses in all three grade factors. Because of these variations for which allowances are made, in actual practice the descriptions presented herewith refer to and describe carcasses and cuts which are typical of the several grades.

Definitions of Terms—Conformation

The term conformation covers the general build, form, shape and contour or outline of the carcass or cut. It is dependent on the skeleton, the depth of flesh, and the thickness and distribution of external fat. Breeding is important and exerts a greater influence on conformation than any other single factor, although care and feed are each important contributing factors. Best conformation in lamb and mutton carcasses involves short, stocky and plump legs, thick, full loins, well-rounded and full backs, thick, well-fleshed ribs, a width of breast and shoulder commensurate with depth of barrel and chest cavity, and short, plump necks. A poor conformation involves angularity in general outline, prominent, back, shoulder and hip bones, long, thin necks and shanks, long, thinly-fleshed legs, and shallow loins and ribs. In poor conformation, there is a decided lack of symmetry in carcass or cut.

Aside from the fact that conformation has much to do with determining the relative attractiveness of the carcass or cut, its chief significance consists in the fact that it indicates the ratio between meat and bone, as well as the ratio between the more desirable cuts, such as the loins, racks and hind legs, and the so-called coarser cuts, such as breasts and chucks.

Finish

Finish refers to the thickness, color, character and distribution of fat. Best finish implies a smooth, even covering of firm, white fat over most of the exterior surface of the carcass, being thickest over loins and racks, but not excessive at any point. It implies a covering of smooth, white interior fat over the kidneys and in the crotch, and a much thinner covering over the inner surface of ribs. The latter may be slightly wavy. It involves relatively liberal deposits of fat between the muscles and along the connective tissue of the chucks and breasts. There is relatively little fat between the muscles of the hind legs even in highly finished carcasses.

In the matter of finish, there is a marked difference in thickness of fat on lamb and mutton. Lamb carcasses seldom show any bunchiness or roughness in distribution of external fat. In fact, the fat is relatively thin and evenly distributed. Well-finished mutton carcasses, however, show much greater depth of fat, particularly over the backs and rumps.

Poor finish implies marked deficiency in external and internal fats, uneven distribution resulting in bunches or rolls, or a fat which is soft, flabby and yellow instead of being firm and white or cream colored.

A high degree of finish adds much to the attractiveness of a carcass or cut, but its chief significance lies in the fact that a certain quantity of intermuscular and intercellular fat is essential to quality and palatability and this usually bears a close relation to the quantity of external and internal fat of the carcass or cut. An over-finished condition, however, results in an uneven distribution of fat, frequently noticeable in rolls or bunches or in excessive quantities of interior fat. Because an excess of fat in lamb or mutton is un-palatable and wasteful, and shows an over-finished condition, such carcasses grade at a lower price. A low percentage of kidney fats indicates a low-grade carcass, whereas excessive quantities of interior fats are the result of an over-finished condition. This, then, is an economic factor which affects production and is reflected in the price received for the live animal.

Quality

Quality is a characteristic of the flesh and the fat included therein. It pertains primarily to the thickness, firmness and strength of both the muscle fiber and the connective tissue. It also involves the quantity, consistency and character of juices and extractives which are contained in the muscle fiber and the fat surrounding the connective tissue. Although color does not actually determine quality, it serves as an excellent index to what the quality of a given piece of meat is, and possesses commercial importance.

Best quality in lamb and mutton implies full, well-developed, firm muscular tissue or flesh with a minimum of strength in fiber and connective tissue. This is necessary to insure tenderness. Allowing for variations between the three groups, the flesh is fine grained and smooth. Its color is light pink in lamb, dark pink to light red in yearling mutton, and somewhat darker in mature mutton.

Poor quality involves the opposite of most of the foregoing characteristics. Although the differences in the color of the flesh are not so outstanding as between good and poor quality beef, yet the difference between lamb and mutton of good quality and poor quality are always sufficiently great to be clearly recognized. Low-quality meats from all bovine animals have darker flesh than meat from high-quality animals of the same group. The ratio between muscle and connective tissue is relatively low as is also the ratio between flesh and bone. The grain is coarse and the general appearance is soft or watery and fibrous.

The significance of quality is great. It determines the palatability of the meat and the ease with which it can be prepared for human consumption. Quality is,therefore,by all means the most important factor in determining grade. The determination of quality presents a rather difficult problem for it is a characteristic which pertains chiefly to the inner or concealed portions of the carcass, and is not apparent to the superficial view in the same degree as conformation and finish. To determine quality exactly, it is essential to have a cut surface or cross section exposed to view. Fortunately, there is such a close relationship between conformation, finish, and quality that the existence in a high degree of the first two virtually insures a high degree of quality.