Beef Yield Grading

S T U D E N T

A Step-wise Procedure for Yield Grading of Beef Carcasses Beef carcasses are divided into five yield (or cutability) grades. The term “cutability” refers to the percentage of carcass weight in boneless, closely trimmed retail cuts from the round, loin, rib and chuck. The following descriptions of carcasses in the yield grades may help you visualize these groups of carcasses.

H A N D O U T

Yield Grade Descriptions 1. Yield Grade 1 a. There is usually only a thin layer of external fat over the round, loin, rib and clod, along with slight deposits of fat in the flank, cod, udder, kidney, pelvic and heart regions. b. There is usually a very thin layer of fat over the outside of the round and over the clod. c. Muscles are usually visible through the fat in many areas of the carcass. 2. Yield Grade 2 a. The carcass is nearly completely covered with external fat, but the lean is very visible through the fat over the outside of the round, chuck and neck. b. There is usually a slightly thin layer of fat over the inside round, loin and rib, coupled with a slightly thick layer of fat over the rump, sirloin and clod. 3. Yield Grade 3 a. The carcass is usually completely covered with external fat, and the lean is plainly visible only through the fat on the lower part of the outside of the round and neck. b. There is usually a slightly thick layer of fat covering the inside round, loin and rib, plus a moderately thick layer of fat over the rump, sirloin and clod. c. There are usually slightly large deposits of fat in the flank, cod or udder, kidney, pelvic and heart regions. 4. Yield Grade 4 a. The carcass is usually completely covered with external fat, except muscle is visible in the shank, outside of the flank and plate regions. b. There is usually a moderately thick layer of external fat over the inside of the round, loin and rib, along with a thick layer of fat over the rump, sirloin and clod. c. There are usually large deposits of fat in the flank, cod or udder, kidney, pelvic and heart regions. Accompanies: Meet Judging & Grading 1

Beef Yield Grading

S T U D E N T

5. Yield Grade 5 a. The carcass generally has a thick layer of fat on all external regions. Extensive fat is found in the brisket, cod or udder, kidney, pelvic and heart regions.

H A N D O U T

Accompanies: Meet Judging & Grading 2

Beef Yield Grading

S T U D E N T

DETERMINING THE YIELD GRADE To facilitate the determination of the yield grade (YG) to the nearest .10 unit for a given carcass, a meat judge should follow five basic steps.

H A N D O U T

Step 1: Determine the Preliminary Yield Grade (PYG) a. Estimate the fat thickness of the beef carcass at three-fourths of the distance across the ribeye from the backbone. b. A change of .10 inch in fat thickness changes the PYG by .25 YG Fat over Ribeye .00 .10 .20 .30 .40 .50 .60

PYG 2.00 2.25 2.50 2.75 3.00 3.25 3.50

Fat over Ribeye .70 .80 .90 1.00 1.10 1.20 1.30

PYG 3.75 4.00 4.25 4.50 4.75 5.00 5.25

c. The PYG is often adjusted by USDA graders. Perhaps 50 percent to 75 percent of all PYG measurements should be adjusted because the fat thickness measurement over the ribeye is not always an accurate index of the PYG of the entire carcass. A wide variation exists in the outside fat distribution of beef carcasses. We will adjust the PYG of about one-third of all carcasses we grade. The maximum upward adjustment will be .40 PYG unit and the maximum downward adjustment will be .30 PYG unit. The criteria which we will use to adjust fat thickness includes fat at the rib-plate juncture, fat over the round and cod or udder fat. We will perfect this skill through practice. d. Record your adjusted PYG estimate as shown in Step five. As beef animals become heavier (especially beyond 1000 pounds in live weight or 600 pounds in carcass weight), they generally accumulate excessive amounts of external (subcutaneous) fat and seam fat (fat between the muscles). This is not true in all cases; nevertheless, the USDA system for yield grading was designed for application to all carcasses.

Accompanies: Meet Judging & Grading 3

Beef Yield Grading

S T U D E N T

Step 2: Carcass Weight to REA Adjustment a.

Estimate the carcass muscling. Estimation of expected cutability of beef carcasses must include a measure of muscling in addition to measures of fatness (fat thickness and percentage internal fat) and size (carcass weight). The area of the ribeye muscle at the interface of the 12th rib is a valid index of carcass muscling, and can be measured using a ribeye dot grid or through visual estimation.

H A N D O U T

b. The most challenging skill to master in meat judging is accurate estimation (within .3 square inch) of REA. The relationship (100 pound carcass weight = 1.2 square inches) of carcass weight to ribeye area is outlined below. A student estimates the difference between the actual size of the ribeye and the standard size of ribeye for its weight (i.e., the data shown below). The difference is then multiplied by three to determine the plus or minus REA adjustment. An example is shown on page five. CARCASS WEIGHT TO REA

HCW (pounds)

REA

HCW (pounds)

REA

400-408 409-416 417-424 425-433 434-441 442-449 450-458 459-466 467-474 475-483 484-491 492-499 500-508 509-516 517-524 525-533 534-541 542-549 550-558 559-566 567-574 575-583 584-591 592-599 600-608 609-616 617-624 625-633 634-641 642-649 650-658 659-666 667-674 675-683 684-691

8.6 8.7 8.8 8.9 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 12.0

700-708 709-716 717-724 725-733 734-741 742-749 750-758 759-766 767-774 775-783 784-791 792-799 800-808 809-816 817-824 825-833 834-841 842-849 850-858 859-866 867-874 875-883 884-891 892-899 900-908 909-916 917-924 925-933 934-941 942-949 950-958 959-966 967-974 975-983 984-991

12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14.0 14.1 14.2 14.3 14.4 14.5 14.6 14.7 14.8 14.9 15.0 15.1 15.2 15.3 15.4 15.5 15.6

Accompanies: Meet Judging & Grading 4

Beef Yield Grading

S T U D E N T

CARCASS WEIGHT TO REA ADJUSTMENT

Carcass Weight 600 524 876 708

REA Needed 11.0 10.0 14.3 12.2

REA Estimated 10.7 13.0 10.6 17.5

REA Adjusted + .1 - .9 +1.1 -1.6

H A N D O U T

Step 3: Adjust for Percent KPH deviations from a base of 3.5 percent Carcasses also accumulate various amounts of fat which protect certain vital organs. Fats surrounding the reproductive system in the pelvic cavity, kidneys in the abdominal cavity and heart in the thoracic cavity are routinely left in beef carcasses slaughtered in U.S. plants. Thus, for accurate estimation of YG, the percentage of carcass weight represented by internal fats (kidney, pelvic, heart) must be estimated. Carcasses with greater than 3.5 percent kidney, pelvic and heart (KPH) fat are penalized. Likewise, carcasses with less than 3.5 percent are credited, according to the official USDA Beef Yield Grade Standards. a. A change in KPH of 1 percent alters the PYG by .20 YG KPH fat, percent .5 1.5 2.5 2.5 4.5 3.5

PYG Adjustment - .6 - .4 - .2 None + .2 + .4

b. A KPH estimate of 2.75 percent would require a -.15 PYG adjustment; 3.75 percent would require a +.05 PYG adjustment. c. A ballpark figure for KPH percentage of carcasses weighing 500 to 700 pound is 2.5 percent + 1 percent (in most cases); whereas the standard for carcasses weighing over 750 pound is 2 + 1 percent. d. KPH will range from about .5 percent to 5.5 percent

Accompanies: Meet Judging & Grading 5

Beef Yield Grading

S T U D E N T

Step 4: Complete Procedure for Determining the Final Yield Grade a. Develop a chart with nine columns as show below. Note that: 1. PYG adjustment values can be cancelled to prevent arithmetic errors. 2. Lines divide the carcass data into groups of three to avoid recording errors. 3. A ü appears after each FYG value to indicate addition and/or subtraction has been verified.

H A N D O U T

ADJUSTMENTS TO PRELIMINARY YIELD GRADE

Carcass No. 1 2 3 4 5 6

PYG

PYG adj.

CWT

REA needed

REA est.

REA adj.

KPH adj.

FYG

3.0 2.5 3.4 4.0 3.7 2.3

-2.4 3.6 -4.2 --

750 600 596 638 854 608

12.8 11.0 10.9 11.4 14.0 11.0

14.8 11.0 11.9 10.0 14.0 16.2

-.6 --.3 +.4 --1.5

--.2 +.1 -+.1 --

2.4 ü 2.2 ü 3.4 ü 4.4 ü 4.3 ü 1.0 ü

b. With more practice, you will wish to use an easier table with five columns: Carcass No. 1 2 3

Adj. PYG

Adj. REA

Adj. KPH

FYG

2.6 2.9 4.5

-.4 +.8 --

+.3 -.3 --

2.5 3.4 4.5

c. This chart shows representative factors from each of the USDA yield grades, so you can gain a better idea of what constitutes a “typical” carcass from that grade level.

TYPICAL FACTORS FOR CARCASSES REPRESENTATIVE OF EACH USDA YIELD GRADE

USDA Factors Yield Fat Carcass a b weight REA c KPH Grade thickness _______________________________________________________________ 1.5 .2 605 14.0 3 2.5 .3 675 12.5 3½ 3.5 .6 700 12.0 3½ 4.5 .9 750 11.5 3 5.5 1.0 800 10.0 3½

Accompanies: Meet Judging & Grading 6

Beef Yield Grading

S T U D E N T

a

As YG increases in numeric value (decreased carcass cutability), carcasses generally increase in external fat thickness. As YG increases in numerical value, carcasses generally increase in weight. c As YG increases in numerical value, carcasses generally decrease in REA. b

Nationally competitive collegiate yield graders completely master the mathematical portion of yield grading on paper prior to spending much time in the cooler practicing on specific carcasses. Following an understanding of the simple arithmetic adjustments, extensive practice on yield grading on at least 500 carcasses will develop a person’s subjective evaluation skills to a competitive level.

H A N D O U T

A skilled meat grader also must learn how to consistently grade carcasses in different beef coolers varying widely in lighting, temperature, rail height, type of cattle and quality of dressing workmanship. Now it’s time to “put your pencil to the paper” and see how well you understand the concepts you have read about and viewed. Try this grading exercise for practice. Good luck! Carcass No. 1 2 3 4 5 6 7 8 9 10

Fat TK. .40 .20 .40 .60 .05 .25 .90 .10 .80 1.2

PYG ___ ___ ___ ___ ___ ___ ___ ___ ___ ___

Wt. 600 725 545 625 705 500 850 625 835 800

REA needed ___ ___ ___ ___ ___ ___ ___ ___ ___ ___

REA est. 11.0 12.1 8.6 13.0 12.7 9.4 16.2 12.5 13.4 8.7

REA adj. ___ ___ ___ ___ ___ ___ ___ ___ ___ ___

KPH 3.5 1.5 2.5 3.5 2.0 2.5 4.5 2.0 4.0 2.5

KPH adj ___ ___ ___ ___ ___ ___ ___ ___ ___ ___

FYG ____ ____ ____ ____ ____ ____ ____ ____ ____ ____

Accompanies: Meet Judging & Grading 7