United States 

Department of 

Agriculture

Agricultural 

Marketing 

Service

Livestock, 

Poultry,

and Seed 

Program

United States Standards 

for Grades of

Carcass Beef

Effective date December 18, 2017
1

United States Standards for Grades of Carcass Beef

The following is a reprint of the Official United States Standards for Grades of Carcass Beef 

promulgated by the Secretary of Agriculture under the Agricultural Marketing Act of 1946 (60 

Stat. 1087; 7 U.S.C. 1621-1627) as amended and related authority in the annual appropriation 

acts for the United States Department of Agriculture (USDA). The standards are reprinted with 

amendments effective December 18, 2017.

The United States Classes, Standards, and Grades of Carcass Beef were removed from the 

Code of Federal Regulations (CFR) on June 30, 1998. They are maintained by the USDA, 

Agricultural Marketing Service (AMS), as AMS 54.100 et seq. This document contains the 

classes, standards, and grades that are the most current to date.

Development of the Standards

The tentative U.S. Standards for the Grades of dressed beef were formulated in 1916. They 

provided the basis of uniformly reporting the dressed beef markets according to grades, which 

was inaugurated as a national service early in 1917. The grade specifications were improved 

from time to time as experience gained through their use indicated what changes were necessary. 

They were published first in mimeograph form in June 1923. After slight changes, they were 

included in the Department’s Bulletin No. 1246 “Market Classes and Grades of Dressed Beef”, 

which was published in August 1924.

Public hearings were held at Portland, OR, Chicago, IL, and New York, NY, in 1925 to give 

producers, slaughterers, wholesale and retail meat dealers, agricultural college workers, and 

others interested in the marketing of livestock and meat an opportunity to make suggestions for 

improving the standards. The sentiment registered at those meetings was overwhelmingly in 

favor of the grades as presented. The few suggestions and criticisms offered were carefully 

considered in subsequent revisions of the standards.

The tentative standards, although designed primarily for meat market reporting purposes, 

were put to further practical uses in numerous ways. During World War I, they were used in 

the selection of beef for the Army, Navy, and Allies. Later they were included in the 

specifications of the Emergency Fleet Corporation for the purchase of its beef supplies. Soon 

thereafter they were incorporated in the specifications of many commercial concerns including: 

steamship lines, restaurants, hotels, dining car services, and hospitals.

The revised grade descriptions were promulgated by the Secretary of Agriculture, June 3, 

1926, as the Official United States Standards for the Grades of Carcass Beef and published in 

Service and Regulatory Announcements No. 99 (B.A.E.). These standards provided the basis 

for grading when the voluntary beef grading and stamping service began in May 1927.

The official standards were amended in July 1939 to provide a single standard for the 

grading and labeling of steer, heifer, and cow beef according to similar inherent quality 

characteristics.

The amendment also changed certain grade terms for steer, heifer, and cow beef from 

“Medium,” “Common,” and “Low Cutter” to “Commercial,” Utility,” and “Canner,” 

respectively. An amendment in November 1941 made similar changes in the grade terms for
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bull and stag beef and established the following grade terminology for all beef: Prime1, Choice, 

Good, Commercial, Utility, Cutter, and Canner. An amendment in October 1949 eliminated all 

references to color of fat.

In December 1950, the official standards for grades of steer, heifer, and cow beef were 

amended by combining the Prime and choice grades and designating them as Prime, renaming 

the Good grade as Choice, and dividing the Commercial grade into two grades by designating the 

beef produced from young animals included in the top half of the grade as Good while retaining 

the Commercial grade designation for the remainder of the beef in that grade. Other revisions in 

the standards for the Prime, Choice, Good, and Commercial grades were made for clarification 

and to facilitate their interpretation. Standards for the Utility, Cutter, and Canner grades were 

not affected. These changes in the standards were a modification of a proposal by USDA to 

revise the standards in August 1949, and were adopted after careful consideration of comments 

received in writing over a period of months and those presented orally at a public hearing in 

Chicago, IL, on June 28, 1950.

In June 1956, the official standards for grades for steer, heifer, and cow beef were amended 

by dividing the Commercial grade into two grades strictly on the basis of maturity with beef 

produced from young animals being designated as Standard while Commercial was retained as 

the grade name for beef produced from mature animals. This change, which was suggested by 

the Cattle and Beef Industry Committee, was identical in principle to that proposed by USDA in 

August 1949.

The official standards for grades of steer, heifer, and cow beef were revised in June 1965 to 

place less emphasis on changes in maturity in the Prime, Choice, Good, and Standard grades.

This change was made to reflect the latest research information available regarding the effect of 

maturity on beef palatability. The minimum marbling permitted in these grades was not 

changed for the very youngest beef. However, the rate of increase in required marbling to offset 

increasing maturity was changed, and the minimum marbling permitted was reduced for more 

mature carcasses by as much as 1-1/2 degrees in Prime, 1 degree in Choice, and 3/4 of a degree 

in Good and Standard. In addition, the revision eliminated consideration of the two degrees of 

marbling in excess of that described as abundant. The manner of evaluating conformation also 

was clarified by providing that carcasses may meet the conformation requirements for a grade 

either through a specified development of muscling or a specified development of muscling and 

fat combined.

This revision also included a requirement that all carcasses be ribbed prior to grading and 

made other minor changes to clarify the intent of the standards and simplify their application.

An added provision established standards for cutability grades of carcasses and certain wholesale 

cuts of all classes of beef. A dual grading system for beef carcasses, involving separate 

identification of differences in quality and in cutability, had been proposed by USDA in April 

1962 and made available for use on a trial basis for a one-year period beginning July 1, 1962.

The cutability standards adopted in 1965 were similar to those included as a part of the dual 

grading system, but modified on the basis of comments from industry and experience gained

during the trial period of the dual grading system.

In July 1973, the official standards were revised to provide separate quality grades for beef 

 

1 The use of the grade specified as “Prime” for beef carcasses and wholesale cuts was suspended 

for the period September 18, 1942, to December 3, 1946, pursuant to amendment 5, Maximum 

Price Regulation 169 of the Office of Price Administration. During that period all carcass beef 

and wholesale cuts that met the specifications of the “Prime” grade were identified with and 

graded as “Choice.”
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from young bulls. Interest in such grades primarily stemmed from earlier research which 

showed that young bulls were superior to steers in rate and efficiency of feedlot gain and from a 

belief by many producers that requiring such beef to be identified as "Bull" was a deterrent to its 

acceptance. Research comparing the palatability of beef from steers and young bulls indicated 

that young bull beef was slightly less palatable and slightly more variable in palatability than 

steer beef. These palatability differences were considered sufficient to preclude the grading of 

young bull beef without a sex identification, therefore this class was designated as "Bullock." 

The quality grade standards for bullock beef were essentially the same as those for steer, heifer, 

and cow beef but provided for only five grades--Prime, Choice, Good, Standard, and Utility. 

"Bull" was retained as the class designation for beef from more mature bulls but the quality 

grades for such beef were eliminated. As a result, the yield grade standards only applied to the 

grading of "Bull" beef. The quality grade standards for "Stag" beef also were eliminated and 

beef formerly included in this class were redesignated as "Bullock" or "Bull" dependent on its 

evidences of maturity. Related changes also were made in the "Application of Standards" 

section and, throughout the standards references to "cutability groups" were changed to "yield 

grades."

In April 1975, the official standards were revised to eliminate the consideration of maturity 

in determining the quality grade (1) of all bullock beef and (2) of all steer, heifer, and cow beef 

included in the youngest maturity group referenced in those standards. That change resulted 

from research reported because a related change was made in the standards for grades of steer, 

heifer, and cow beef in 1965, and which showed that, for beef in this youngest maturity group, 

increases in maturity did not have a detrimental effect on palatability. In the Prime, Choice, and 

Standard grades, the minimum marbling requirements for all such beef were revised to be the 

same as previously required for the youngest beef in each of these grades. However, for the 

Good grade, the minimum marbling requirements for the very youngest beef were increased onehalf degree. For the more mature beef in each of these grades of steer, heifer, and cow beef, the 

previous rate of increase in marbling with increased maturity was retained but the minimum 

marbling requirements were reduced to coordinate them with the changed marbling requirements 

for beef in the youngest maturity group. In the Prime, Choice, and Standard grades, this 

reduction was one full degree. In the Good grade, the reduction was one-half a degree. In this 

same revision, conformation also was eliminated as a quality grade factor and all carcasses 

graded were required to be identified for both quality grade and yield grade. Variations in 

conformation had been shown to be unrelated to differences in palatability and their effect on 

yields of retail cuts was better measured by the yield grades. The combination of these two 

changes (1) eliminated a factor (conformation) whose use had contributed to variations in the 

quality of beef in the quality grades, and (2) provided an improved measure of carcass value. 

Both of these changes were originally proposed by USDA in 1962. An additional change 

reduced the maximum maturity permitted for steer, heifer, and cow beef in the Good and 

Standard grades to the same as that permitted in Prime and Choice. The changes that were made 

in the Good grade were designed to reduce the variability of the beef in that grade and to make it 

a very restrictive, leaner grade than Choice which might be more widely used than the previous 

Good grade. These revised standards were originally scheduled to become effective on April 14, 

1975, but because of a series of court actions, they were not implemented until February 23, 

1976.
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In October 1980, the official standards for grades of steer, heifer, cow, and bullock beef and 

the related regulations were amended. The conditions necessary for removal of yield grade 

designations from officially graded beef were clarified by 1) specifying a maximum fat thickness 

(3/4 inch) to be met prior to removal and, 2) by specifying the items to which the requirement 

applies. Specific language was added to make carcasses which have had the characteristics of 

the ribeye or the thickness of fat over the ribeye altered ineligible for grading and to specify that 

the presentation of such carcasses for an official grade determination shall be considered a 

fraudulent or deceptive practice. Changes were made in the regulations to provide generally for 

grading only in carcass form and only in the establishment where the animal was slaughtered or 

initially chilled. In addition, a 10-minute minimum period between ribbing and presentation for 

grading was established. These changes were designed to increase the accuracy and uniformity 

of beef grade determinations and to provide more accurate grade information to purchasers of 

beef by reducing the variation in conditions under which grading could be accomplished.

In November 1987, the official standards were revised to change the name of the U.S. Good 

grade to U.S. Select for steer, heifer, cow, and bullock carcasses. The revision did not change 

the requirements for the grade, only the grade name. Although the 1975 changes in the Good 

grade had made a very restrictive, leaner grade than Choice, the Good grade had not been widely 

used. This change provided the industry an improved grade term to use in the marketing of this 

type of beef to consumers who desire an alternative to Choice.

In April 1989, the official standards were revised to allow the official grade to consist of the 

quality grade only, the yield grade only, or a combination of both. No changes were made in the 

actual yield grade or quality grade requirements. The change was made to allow the industry 

greater flexibility in the use of the beef grading system in order to provide consumers with the 

trimness levels desired.

In January 1997, the official standards were revised to restrict the Select grade to A maturity 

only and to raise the marbling degree required for Choice to minimum modest throughout B 

maturity. These changes were made to improve the uniformity and consistency within the 

Choice and Select grades.

In August 2001, a grading instrument was approved for use in determining the size of the 

ribeye area. Instrument assessment of yield grade was approved for use in March 2007, followed 

by assessment for marbling in September 2009. Implementing instrument technology helped the 

beef processing industry to provide more detailed carcass information to cattle producers.

In March 2016, changes were made that informed the public of administrative updates to the 

United States Standards for Grades of Carcass Beef. The updates included a reference to the 

removal of this standard from the Code of Federal Regulations in 1998; incorporated language that 

documents the use of photographs, objective aids or devices (e.g., instrument grading and other 

future technologies) used for grading; updated the examples for yield grading to reflect gains in 

carcass weights; and updated the names of organization units that resulted from the merger of 

Poultry Programs and Livestock and Seed Program into the Livestock, Poultry, and Seed Program

(LPS).

In April 2016, AMS received a petition from industry stakeholders requesting that the beef 

standards be amended to include dentition and documentation of actual age as an additional 

determination of maturity grouping for official quality grading. The beef standards relied solely 

on skeletal and lean (physiological) maturity, and although never intended to be a definitive 

method to determine the age of cattle at the time of slaughter and instead utilized to predict beef 

palatability, the maturity groupings have historically been roughly correlated to different age 

categories.

Recent research, however, indicated that carcasses from grain-fed steers and heifers that are 
5

deemed less than 30 months of age (MOA), based on dentition, are similar in palatability to A 

maturity carcasses determined via physiological maturity and thus could be classified A maturity 

for grading purposes even though the physiological maturity characteristics of B or older maturity 

groupings may be present. Further, dentition was already used by the Food Safety Inspection 

Service (FSIS) to determine animal age at time of slaughter on all cattle in order to determine 

whether their age is less than or greater than 30 MOA.

In June 2017, AMS sought public comment on proposed revisions to the beef standards 

through a notice in the Federal Register. Based on comments received, AMS proceeded with this 

revision to incorporate dentition and documentation of actual age as means of determining 

maturity groupings, and thus eligibility for Prime, Choice, and Select grade designations. A final 

notice indicating the changes published to the Federal Register on December 5, 2017.

§54.102 Scope.

These standards for grades of beef are written primarily in terms of carcasses. However, they 

also are applicable to the grading of sides. To simplify phrasing of the standards, the words 

“carcass” and “carcasses” are used to also mean “side” or “sides.”

§54.103 Classes of beef carcasses.

(a) Class determination of beef carcasses is based on evidences of maturity and apparent

sex condition at the time of slaughter. The classes of beef carcasses are steers, bullocks, bulls, 

heifers, and cows. Carcasses from males -- steers, bullocks, and bulls -- are distinguished from 

carcasses from females -- heifers and cows -- as follows:

(1) Steer, bullock, and bull carcasses have a “pizzle muscle” (attachment of the penis) and 

related “pizzle eye” adjacent to the posterior end of the aitchbone.

(2) Steer, bullock, and bull carcasses have, if present, rather rough, irregular fat in the region 

of the cod. In heifer and cow carcasses, the fat in this region, if present, is much smoother.

(3) In steer, bullock, and bull carcasses, the area of lean exposed immediately ventral to the 

aitchbone is much smaller than in heifer and cow carcasses.

(b) Steer, bullock, and bull carcasses are distinguished by the following:

(1) In steer carcasses, the “pizzle muscle” is relatively small, light red in color, and fine in 

texture and the related “pizzle eye” is relatively small.

(2) In bullock and bull carcasses, the “pizzle muscle” is relatively large, dark red in color, 

and coarse in texture and the related “pizzle eye” is relatively large.

(3) Bullock and bull carcasses usually have a noticeable crest.

(4) Bullock and bull carcasses also usually have a noticeably developed small round muscle 

adjacent to the hipbone commonly referred to as the “jump muscle.” However, in carcasses 

with a considerable amount of external fat, the development of this muscle may be obscured.

(5) Although the development of the secondary sex characteristics is given primary 

consideration in distinguishing steer carcasses from bullock or bull carcasses, this differentiation 

is also facilitated by consideration of the color and texture of the lean. In bullock and bull 

carcasses, the lean is frequently at least dark red in color with a dull, “muddy” appearance -- and 

in some cases it may have an iridescent sheen. Also, it frequently has an “open” texture.

(6) The distinction between bullock and bull carcasses is based solely on their evidences of 

skeletal maturity. Carcasses with the maximum maturity permitted in the bullock class have 

slightly red and slightly soft chine bones, and the cartilages on the ends of the thoracic vertebrae 

have some evidence of ossification; the sacral vertebrae are completely fused; the cartilages on 

the ends of the lumbar vertebrae are nearly completely ossified; and the rib bones are slightly 
6

wide and slightly flat. Bull carcasses have evidences of more advanced maturity.

(c) Heifer and cow carcasses are distinguished by the following:

(1) Heifer carcasses have a relatively small pelvic cavity and a slightly curved aitchbone. In 

cow carcasses, the pelvic cavity is relatively large and the aitchbone is nearly straight.

(2) In heifer carcasses, the udder usually will be present. In cow carcasses, the udder usually 

will have been removed. However, neither of these are requirements.

§54.104 Application of standards for grades of carcass beef.

(a) The carcass beef grades identify two separate general considerations 1) the indicated 

yield of closely trimmed (1/2 inch fat or less), boneless retail cuts expected to be derived from 

the major wholesale cuts (round, sirloin, short loin, rib, and square-cut chuck) of a carcass, herein 

referred to as the “yield grade,” and, 2) characteristics of the meat which predict the palatability 

of the lean, herein referred to as the “quality grade.” When officially graded, the grade of a steer, 

heifer, cow, or bullock carcass may consist of the quality grade only, the yield grade only, or a 

combination of the quality grade and the yield grade. The grade of a bull carcass consists of the 

yield grade only.

(b) The carcass beef grade standards are written so that the quality grade and yield grade 

standards are contained in separate sections. The quality grade section is divided further into

two separate sections applicable to carcasses from: (1) steers, heifers, and cows, and (2) 

bullocks. Eight quality grade designations -- Prime, Choice, Select, Standard, Commercial, 

Utility, Cutter, and Canner -- are applicable to steer and heifer carcasses. Except for Prime, the 

same designations apply to cow carcasses. The quality grade designations for bullock carcasses 

are Prime, Choice, Select, Standard, and Utility. There are five yield grades applicable to all

classes of beef, denoted by numbers 1 through 5, with Yield Grade 1 representing the highest 

degree of cutability.

(c) When officially graded, bullock and bull beef will be further identified for its sex 

condition; steer, heifer, and cow beef will not be so identified. The designated grades of bullock 

beef are not necessarily comparable in quality or cutability with a similarly designated grade of 

beef from steers, heifers, or cows. The cutability of a designated yield grade of bull beef is not 

necessarily comparable with a similarly designated yield grade of steer, heifer, cow, or bullock 

beef.

(d) USDA uses photographs and other objective aids or devices designated by the 

Agricultural Marketing Service (AMS)2 in the correct interpretation and application of the 

standards.

(e) To determine the grade of a carcass, it must be split down the back into two sides and one 

or both sides must be partially separated into a hindquarter and forequarter by cutting it with a 

saw and knife insofar as practicable, as follows: A saw cut perpendicular to both the long axis 

and split surface of the vertebral column is made across the 12th thoracic vertebra at a point 

which leaves not more than one-half of this vertebra on the hindquarters. The knife cut across 

the ribeye muscle starts -- or terminates -- opposite the above-described saw cut. From that point 

it extends across the ribeye muscle perpendicular to the outside skin surface of the carcass at an 

angle toward the hindquarter which is slightly greater (more nearly horizontal) than the angle 

made by the 13th rib with the vertebral column of the hindquarter posterior to that point. As a 

 

2 Information concerning such devices and their use may be obtained from the AMS Livestock, 

Poultry, and Seed Program.
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result of this cut, the outer end of the cut surface of the ribeye muscle is closer to the 12th rib 

than is the end next to the chine bone. Beyond the ribeye, the knife cut shall continue between 

the 12th and 13th ribs to a point which will adequately expose the distribution of fat and lean in 

this area. The knife cut may be made prior to or following the saw cut but must be smooth and 

even, such as would result from a single stroke of a very sharp knife.

(f) Other methods of ribbing may prevent an accurate evaluation of the grade determining 

characteristics. Therefore, carcasses ribbed by other methods will be eligible for grading only if 

an accurate grade determination can be made by the official grader under the standards.

(g) Beveling of the fat over the ribeye, application of pressure, or any other influences which 

may alter the characteristics of the ribeye or thickness of fat over the ribeye prevent an accurate 

grade determination. Therefore, carcasses subjected to such influences shall not be eligible for 

grade determinations, and the presentation of such carcasses for official grade determinations 

shall be considered a fraudulent or deceptive practice in connection with the services requested 

for such carcasses. Carcasses that have had more than minor amounts of external fat removed 

shall not be eligible for a yield grade determination, although carcasses with only minor amounts 

of external fat removed may be yield graded if the official grader determines that an accurate 

yield grade determination can be made. Although entire carcasses with more than minor 

amounts of lean removed from the major wholesale cuts (round, sirloin, short loin, rib, or squarecut chuck) shall not be eligible for grade determinations, the remaining portions of these 

carcasses which are unaffected by the removal of lean shall remain eligible for grade 

determinations, provided that a cross section at the 12th-13th rib is available and accurate grade 

determinations may be made.

(h) When both sides of a carcass have been ribbed prior to presentation for grading and

the characteristics of the two ribeyes (area, marbling, color, texture, and firmness) would 

justify different quality and/or yield grades, the final grade of the carcass shall reflect the 

“highest” of each of these grades as determined from either side.

(i) To meet the demand of export trade or changing trade practices, grading of carcasses 

ribbed other than between the 12th and 13th ribs may be approved by the Director, LPS Quality 

Assessment Division. In such cases, grading shall be based on the requirements specified in 

these standards and shall be consistent with the normal development of grade characteristics in 

various parts of a carcass of the quality level involved. When an exception is granted for export 

trade, such carcasses shall be identified with the word “EXPORT” in such a manner that will 

clearly distinguish them from other officially graded beef.

(j) Carcasses qualifying for any particular grade may vary with respect to their relative 

development of the various grade factors. There will be carcasses that qualify for a particular 

grade, some of whose characteristics may be more nearly typical of another grade. For example, 

in comparison with the descriptions of maturity contained in the standards, a particular carcass 

might have a greater relative degree of ossification of the cartilages on the ends of its lumbar 

vertebrae than its other evidences of maturity. In such instances, the maturity of the carcass is 

not determined solely by the ossification of the lumbar vertebrae but neither is this ignored. All 

of the maturity-indicating factors are considered. In making any composite evaluation of two or 

more factors, it must be remembered that they seldom are developed to the same degree.

Because it is impractical to describe the nearly limitless number of recognizable combinations of 

characteristics, the standards for each quality grade and yield grade describe only beef which has 

a relatively similar degree of development of the various factors affecting its quality and yield.

Also, the quality grade and yield grade standards each describe beef which is representative of 

the lower limits of each quality grade and yield grade.

(k) For steer, heifer, and cow beef, quality of the lean is evaluated by considering its marbling 
8

and firmness as observed in a cut surface in relation to carcass evidences of maturity. The 

maturity of the carcass is determined through one of three methods:

(1) Dentition as monitored by the Food Safety and Inspection Service (FSIS). Carcasses 

determined to be less than 30 months of age (MOA) will be classified as A maturity, and with the 

exception of dark cutting lean characteristics, the final quality grade will be determined by the 

degree of marbling. Any carcasses under 30 MOA exhibiting advanced skeletal maturity traits 

(as described for D- and E maturity) will not be eligible for the Prime, Choice, Select, or 

Standard grades and will be graded according to their skeletal, lean, and marbling traits 

accordingly;

(2) Documentation of age as verified through USDA-approved programs and by FSIS atthe 

slaughter facility. Carcasses determined to be less than 30 MOA by age verification will be 

classified as A-maturity and, with the exception of dark cutting lean characteristics, the final 

quality grade will be determined by the degree of marbling. Any carcasses under 30 MOA 

exhibiting advanced skeletal maturity traits (as described for D- and E-maturity) will not be 

eligible for the Prime, Choice, Select, or Standard grades and will be graded according to their 

skeletal, lean, and marbling traits accordingly; or

(3) Through evaluation of the size, shape, and ossification of the bones and cartilages, 

especially the split chine bones, and the color and texture of the lean flesh. Carcasses determined 

to be greater than 30 MOA will be eligible for all quality grade classifications with the final 

quality grade being determined by the evaluation of the degree of marbling and any adjustment 

factors based on advanced skeletal maturity characteristics. In the split chine bones, ossification 

changes occur at an earlier stage of maturity in the posterior portion of the vertebral column 

(sacral vertebrae) and at progressively later stages of maturity in the lumbar and thoracic 

vertebrae. The ossification changes that occur in the cartilages on the ends of the split thoracic

vertebrae are especially useful in evaluating maturity and these vertebrae are referred to frequently 

in the standards. Unless otherwise specified in the standards, whenever reference is made to the 

ossification of cartilages on the thoracic vertebrae, this shall be construed to refer to mature beef 

whose ribs will be very wide and flat.

(l) In steer, heifer, and cow beef, the color and texture of the lean flesh also undergo 

progressive changes with advancing maturity. In the very youngest carcasses considered as 

“beef,” the lean flesh will be very fine in texture and light grayish red in color. In progressively 

more mature carcasses, the texture of the lean will become coarser and the color of the lean will 

become darker red. In very mature beef, the lean flesh will be very coarse in texture and very 

dark red in color. Since the color of lean also is affected by variations in quality, references to 

the color of lean in the standards for a given degree of maturity vary slightly with different levels 

of quality. In determining the maturity of a carcass in which the skeletal evidences of maturity 

are different from those indicated by the color and texture of the lean, slightly more emphasis is 

placed on the characteristics of the bones and cartilages than on the characteristics of the lean. In 

no case can the overall maturity of the carcass be considered more than one full maturity group 

different from that indicated by its bones and cartilages.

(m)The preceding two paragraphs also are applicable to the determination of quality in 

bullock beef, except for carcasses having darker colors of lean than specified in the standardsfor 

the quality level for which they would otherwise qualify. In such carcasses, maturity will be 

evaluated on the basis of skeletal characteristics only, and the final grade will be determined in 

accordance with the procedures specified in the standards for grading “dark-cutting beef.”

(n) In determining compliance with the maximum maturity limits for the Prime, Choice, and 

Standard grades for steer, heifer, and cow carcasses, color and texture of the lean are considered 

only when the maturity-indicating factors, other than color and texture of the lean, indicate only 
9

a slightly more advanced degree of maturity than that specified as maximum for these grades, 

and provided further that the lean is considerably finer in texture and lighter in color than normal 

for the grade and maturity involved. The same principle, in reverse, is likewise applicable to 

determining compliance with the minimum maturity limits of the Commercial grade.

(o) These standards are applicable to the grading of beef throughout the full range of 

maturity within which cattle are marketed. However, in steer, heifer, and cow carcasses, the 

range of maturity permitted within each of the grades varies considerably. The Prime, Choice, 

Select, and Standard grades are restricted to beef from young cattle; the Commercial grade is 

restricted to beef from cattle too mature for Prime, Choice, and Standard; and the Utility, Cutter, 

and Canner grades may include beef from animals of all ages. By definition, bullock carcasses 

are restricted to those whose evidences of maturity do not exceed those specified for the juncture 

of the two youngest maturity groups referenced in the standards for steer, heifer, and cow 

carcasses. Except for the youngest maturity group and the Choice grade in the second maturity 

group, within any specified grade, the requirements for marbling increase progressively with 

evidences of advancing maturity. In the youngest maturity group, the marbling requirements do 

not increase progressively with evidences of advancing maturity. For each grade, the firmness 

requirements are different for each maturity group, but, within each maturity group, the firmness 

requirements do not increase progressively with evidences of advancing maturity. Also, 

regardless of the extent to which marbling may exceed the minimum of a grade, a carcass must 

meet the minimum firmness requirements for its maturity to qualify for that grade. To facilitate

the application of these principles, the standards recognize five different maturity groups and 

seven different degrees of marbling. The five maturity groups are identified in Figure 1 as A, B, 

C, D, and E in order of increasing maturity. The limits of these five maturity groups are 

specified in the grade descriptions for steer, heifer, and cow carcasses. The A maturity portion 

of the figure is the only portion applicable to bullock carcasses. The degrees of marbling 

referenced in the specifications, in order of descending quantity are: Slightly abundant, 

moderate, modest, small, slight, traces, and practically devoid. However, for carcass evaluation 

programs and other purposes, three higher degrees are recognized -- moderately abundant, 

abundant, and very abundant. Illustrations of the lower limits of nine of these ten degrees of 

marbling are available from the USDA.

(p) The relationship between marbling, maturity and quality grade is shown in Figure 1. This 

figure assumes that the firmness of lean is comparably developed with the degree of marbling and 

that the carcass is not a “dark cutter.” From this figure it can be seen, for instance, that the 

minimum marbling requirement for Choice varies from a minimum small amount for carcasses 

throughout the youngest maturity group to a maximum small amount for carcasses having the 

maximum maturity permitted in Choice. Likewise, in the Commercial grade the minimum

marbling requirement varies from a minimum small amount in beef with the minimum maturity 

permitted to a maximum moderate amount in beef from very mature animals. The marbling and 

other lean flesh characteristics specified for the various grades are based on their appearance in the 

ribeye muscle of properly chilled carcasses that are ribbed between the 12th and 13th ribs.

For carcass evaluation programs and other purposes, in the Prime and Commercial grades,

each additional degree of marbling (up to three) greater than specified as minimum for each of 

these grades is equal to one-third of a grade of higher quality.
10

(q) References to color of lean in the standards for steer, heifer, and cow beef involve only 

colors associated with changes in maturity. They are not intended to apply to colors of lean 

associated with so-called “dark-cutting beef.” “Dark-cutting beef” is believed to be the result of a 

reduced sugar content of the lean at the time of slaughter. As a result, this condition does not have 

the same significance in grading as do the darker shades of red associated with advancing 

maturity. The dark color of the lean associated with “dark-cutting beef” is present in varying 

degrees from that which is barely evident to so-called “black cutters” in which the lean is actually 

nearly black in color and usually has a “gummy” texture. Although there is little or no evidence 

which indicates that the “dark-cutting” condition has any adverse effect on palatability, it is 

considered in grading because of its effect on acceptability and value. Depending on the degree to 

which this characteristic is developed, the final grade of carcasses which otherwise would qualify 

for the Prime, Choice, or Select grades may be reduced as much as one full grade. In beef 

otherwise eligible for the Standard or Commercial grade, the final grade may be reduced as much 

as one-half of a grade. In the Utility, Cutter, and Canner grades, this condition is not considered.

(r) The yield grade of a beef carcass is determined by considering four characteristics: (1) the 

amount of external fat, (2) the amount of kidney, pelvic, and heart fat, (3) the area of the ribeye 

muscle, and (4) the carcass weight.

(s) The amount of external fat on a carcass is evaluated in terms of the thickness of this fat 

over the ribeye muscle, measured perpendicular to the outside surface at a point three-fourths of 

the length of the ribeye from its chine bone end. 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 fat in such areas 

as the brisket, plate, flank, cod or udder, inside round, rump, and hips in relation to the actual 

thickness of fat over the ribeye. Thus, in a carcass which is fatter over other areas than is 

indicated by the fat measurement over the ribeye, the measurement is adjusted upward. 

Conversely, in a carcass which has less fat over the other areas than is indicated by the fat 
11

measurement 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 

one-tenth or two-tenths of an inch is not uncommon. In some carcasses a greater adjustment 

may be necessary. As the amount of external fat increases, the percent of retail cuts decreases --

each one-tenth inch change in adjusted fat thickness over the ribeye changes the yield grade by 

25 percent of a yield grade.

(t) The amount of kidney, pelvic, and heart fat considered in determining the yield grade 

includes the kidney knob (kidney and surrounding fat), the lumbar and pelvic fat in the loin and 

round, and the heart fat in the chuck and brisket area 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, pelvic, and heart fat increases, the 

percent of retail cuts decreases -- a change of 1 percent of the carcass weight in these fats 

changes the yield grade by 20 percent of a yield grade.

(u) The area of the ribeye is determined where this muscle is exposed by ribbing. This area 

usually is estimated subjectively; however, it may be measured. An increase in the area of ribeye 

increases the percent of retail cuts -- a change of 1 square inch in area of ribeye changes the yield 

grade by approximately 30 percent of a yield grade.

(v) Hot carcass weight (or chilled carcass weight x 102 percent) is used in determining the 

yield grade. As carcass weight increases, the percent of retail cuts decreases -- a change of 100 

pounds in hot carcass weight changes the yield grade by approximately 40 percent of a yield 

grade.

(w) The standards include a mathematical equation for determining yield grade. This grade 

is expressed as a whole number. For example, if the computation results in a designation of 3.9, 

the final grade is 3 -- it is not rounded to 4. If yield grade is determined through objective means 

(e.g. instrumentation), the resulting designation may include a fractional part. Regardless of the

means of determination, the aggregate is dropped for consideration of grade application.

(x) The yield grade standards for each of the first four yield grades list characteristics of two 

carcasses of two different weights together with descriptions of the usual fat deposition pattern 

on various areas of the carcass. These descriptions are not specific requirements -- they are 

included only as illustrations of carcasses which are near the borderlines between groups. For 

example, the characteristics listed for Yield Grade 1 represent carcasses which are near the 

borderline of Yield Grades 1 and 2. These descriptions facilitate the subjective determination of 

the yield grade without making detailed measurements and computations. The yield grade for 

most beef carcasses can be determined accurately on the basis of a visual appraisal. Objective 

detailed measurements extend the accuracy to fractional parts.

§54.105 Specifications for official United States standards for grades of carcass beef (yield).

(a) The yield grade of a beef carcass is determined on the basis of the following equation: 

Yield grade -- 2.50 + (2.50 x adjusted fat thickness, inches) + (0.20 x percent kidney, pelvic, and 

heart fat) + (0.0038 x hot carcass weight, pounds) - (0.32 x area ribeye, square inches).

(b) The following descriptions provide a guide to the characteristics of carcasses in each 

yield grade to aid in determining yield grades subjectively.

(1) Yield Grade 1. (i) A carcass in Yield Grade 1 usually has only a thin layer of external fat 

over the ribs, loins, rumps, and clods, and slight deposits of fat in the flanks and cod or udder. 

There is usually a very thin layer of fat over the outside of the rounds and over the tops of the 

shoulders and necks. Muscles are usually visible through the fat in many areas of the carcass.

(ii) A 700-pound carcass of this yield grade, which is near the borderline of Yield Grades 1 

and 2, might have two-tenths inch of fat over the ribeye, 12.5 square inches of ribeye, and 1.5 
12

percent of its weight in kidney, pelvic, and heart fat.

(iii)A 1,100-pound carcass of this yield grade, which is near the borderline of Yield Grades 1 

and 2, might have four-tenths inch of fat over the ribeye, 19.1 square inches of ribeye, and 2.0 

percent of its weight in kidney, pelvic, and heart fat.

(2) Yield Grade 2. (i) A carcass in Yield Grade 2 usually is nearly completely covered with 

fat, but the lean is plainly visible through the fat over the outside of the rounds, the tops of the 

shoulders, and the necks. There usually is a slightly thin layer of fat over the loins, ribs, and 

inside rounds and the fat over the rumps, hips, and clods usually is slightly thick. There are 

usually small deposits of fat in the flanks and cod or udder.

(ii) A 700-pound carcass of this yield grade, which is near the borderline of Yield Grades 2 

and 3, might have five-tenths inch of fat over the ribeye, 12.3 square inches of ribeye, and 2.5 

percent of its weight in kidney, pelvic, and heart fat.

(iii)A 1,100-pound carcass of this yield grade, which is near the borderline of Yield Grades 2 

and 3, might have six-tenths inch of fat over the ribeye, 18.1 square inches of ribeye, and 3.0 

percent of its weight in kidney, pelvic, and heart fat.

(3) Yield Grade 3. (i) A carcass in Yield Grade 3 usually is completely covered with fat and 

the lean usually is visible through the fat only on the necks and the lower part of the outside of 

the rounds. There usually is a slightly thick layer of fat over the loins, ribs, and inside rounds 

and the fat over the rumps, hips, and clods usually is moderately thick. There usually are slightly 

large deposits of fat in the flanks and cod or udder.

(ii) A 700-pound carcass of this yield grade, which is near the borderline of Yield Grades 3 

and 4, might have seven-tenths inch of fat over the ribeye, 11.0 square inches of ribeye, and 3.0 

percent of its weight in kidney, pelvic, and heart fat.

(iii)A 1,100-pound carcass of this yield grade, which is near the borderline of Yield Grades 3 

and 4, might have eight-tenths inch of fat over the ribeye, 16.9 square inches of ribeye, 3.5 

percent of its weight in kidney, pelvic, and heart fat.

(4) Yield Grade 4. (i) A carcass in Yield Grade 4 usually is completely covered with fat.

The only muscles usually visible are those on the shanks and over the outside of the plates 

and flanks. There usually is a moderately thick layer of fat over the loins, ribs, and inside rounds 

and the fat over the rumps, hips, and clods usually is thick. There usually are large deposits of 

fat in the flanks and cod or udder.

(ii) A 700-pound carcass of this yield grade, which is near the borderline of Yield Grades 4 

and 5, might have nine-tenths inch of fat over the ribeye, 9.8 square inches of ribeye, and 3.5 

percent of its carcass weight in kidney, pelvic, and heart fat.

(iii)A 1,100-pound carcass of this yield grade, which is near the borderline of Yield Grades 4 

and 5, might have one inch of fat over the ribeye, 15.6 square inches of ribeye, and 4.0 percent of 

its weight in kidney, pelvic and heart fat.

(5) Yield Grade 5. A carcass in Yield Grade 5 usually has more fat on all of the various 

parts, a smaller area of ribeye, and more kidney, pelvic, and heart fat than a carcass in Yield 

Grade 4.

§54.106 Specifications for official United States standards for grades of carcass beef 

(quality-steer, heifer, cow).

(a) Prime. (1) Depending on their degree of maturity, beef carcasses possessing the 

minimum requirements for the Prime grade vary in their other indications of quality as evidenced 

in the ribeye muscle. Minimum quality characteristics are described for two maturity groups 

which cover the entire range of maturity permitted in the Prime grade.
13

(2) Carcasses in the younger group, range from the youngest that are eligible for the beef 

class to those at the juncture of the two maturity groups, which have slightly red and slightly soft 

chine bones and cartilages on the ends of the thoracic vertebrae that have some evidence of 

ossification. In addition, the sacral vertebrae are completely fused and the cartilages on the ends 

of the lumbar vertebrae are nearly completely ossified. The rib bones are slightly wide and 

slightly flat and the ribeye muscle is light red in color and is fine in texture. In carcasses 

throughout the range of maturity included in this group, a minimum slightly abundant amount of 

marbling is required (see Figure 1) and the ribeye muscle is moderately firm.

(3) Carcasses in the older group, range from those described above as representative of the 

juncture of the two groups to those at the maximum maturity permitted in the Prime grade, which 

have chine bones tinged with red and cartilages on the ends of the thoracic vertebrae that are 

partially ossified. In addition, the sacral vertebrae are completely fused, the cartilages on the 

ends of the lumbar vertebrae are completely ossified, and the cut surface of the lean tends to be 

fine in texture. The minimum degree of marbling required increases with advancing maturity 

throughout this group from minimum slightly abundant to maximum slightly abundant (see 

Figure 1) and the ribeye muscle is firm.

(4) Beef produced from cows is not eligible for the Prime grade.

(b) Choice. (1) Depending on their degree of maturity, beef carcasses possessing the 

minimum requirements for the Choice grade vary in their other indications of quality as 

evidenced in the ribeye muscle. Minimum quality characteristics are described for two maturity 

groups, which cover the entire range of maturity permitted in the Choice grade.

(2) Carcasses in the younger group, range from the youngest that are eligible for the beef 

class, to those at the juncture of the two maturity groups, which have slightly red and slightly 

soft chine bones and cartilages on the ends of the thoracic vertebrae that have some evidence of 

ossification. In addition, the sacral vertebrae are completely fused and the cartilages on the ends 

of the lumbar vertebrae are nearly completely ossified. The rib bones are slightly wide and 

slightly flat and the ribeye muscle is moderately light red in color and is fine in texture. In 

carcasses throughout the range of maturity included in this group, a minimum small amount of 

marbling is required (see Figure 1) and the ribeye muscle may be slightly soft.

(3) Carcasses in the older group range from those described above as representative of the 

juncture of the two groups, to those at the maximum maturity permitted in the Choice grade, 

which have chine bones tinged with red and cartilages on the ends of the thoracic vertebrae are 

partially ossified. In addition, the sacral vertebrae are completely fused, the cartilages on the 

ends of the lumbar vertebrae are completely ossified, and the cut surface of the lean tends to be 

fine in texture. In carcasses throughout the range of maturity included in this group, a minimum 

modest amount of marbling is required (see Figure 1) and the ribeye muscle is slightly firm.

(c) Select. (1) In carcasses throughout the range of maturity permitted in the Select grade, the 

minimum marbling required is a minimum slight amount (see Figure 1) and the ribeye may be 

moderately soft.

(2) Carcasses in the maturity group permitted range from the youngest that are eligible for 

the beef class, to those at the juncture of the two maturity groups, which have slightly red and 

slightly soft chine bones and cartilages on the ends of the thoracic vertebrae that have some 

evidence of ossification. In addition, the sacral vertebrae are completely fused and the cartilages 

on the ends of the lumbar vertebrae are nearly completely ossified. The rib bones are slightly 

wide and slightly flat and the ribeye muscle is slightly light red in color and is fine in texture. In 

carcasses throughout the range of maturity included in this group, a minimum slight amount of 

marbling is required (see Figure 1) and the ribeye may be moderately soft.

(d) Standard. (1) Depending on their degree of maturity, beef carcasses possessing the 
14

minimum requirements for the standard grade vary in their other indications of quality as 

evidenced in the ribeye muscle. Minimum quality characteristics are described for two maturity 

groups which cover the entire range of maturity permitted in the Standard grade.

(2) Carcasses in the younger group range from the youngest that are eligible for the beef class 

to those at the juncture of the two maturity groups, which have slightly red and slightly soft chine 

bones and cartilages on the ends of the thoracic vertebrae that have some evidence of 

ossification. In addition, the sacral vertebrae are completely fused and the cartilages on the ends 

of the lumbar vertebrae are nearly completely ossified. The rib bones are slightly wide and 

slightly flat and the ribeye muscle is slightly dark red in color and is fine in texture. In carcasses 

throughout the range of maturity included in this group, a minimum practically devoid amount of 

marbling is required (see Figure 1) and the ribeye muscle may be soft.

(3) Carcasses in the older group range from those described above as representative of the 

juncture of the two groups to those at the maximum maturity permitted in the Standard grade, 

which have chine bones tinged with red and cartilages on the ends of the thoracic vertebrae that 

are partially ossified. In addition, the sacral vertebrae are completely fused, the cartilages on the 

ends of the lumbar vertebrae are completely ossified, and the cut surface of the lean is 

moderately fine in texture. The minimum degree of marbling required increases with advancing 

maturity throughout this group from minimum practically devoid to maximum practically devoid 

(see Figure 1) and the ribeye muscle may be moderately soft.

(e) Commercial. (1) Commercial grade beef carcasses are restricted to those with evidences 

of more advanced maturity than permitted in the Standard grade. Depending on their degree of 

maturity, beef carcasses possessing the minimum requirements for the Commercial grade vary in 

their other indications of quality as evidenced in the ribeye muscle. Minimum quality 

characteristics are described for the youngest and the most mature of these groups. The 

requirements for the intermediate group are determined by interpolation between the 

requirements indicated for the two groups described.

(2) Carcasses in the youngest group permitted in the Commercial grade range from those 

with indications of maturity barely more advanced than described as maximum for the Standard 

grade, to those with moderately hard, rather white chine bones and with cartilages on the ends of 

the thoracic vertebrae that show considerable ossification but the outlines of the cartilages are 

still plainly visible. In addition, the rib bones are moderately wide and flat and the ribeye muscle 

is moderately dark red and slightly coarse in texture. The minimum degree of marbling required 

increases with advancing maturity throughout this group from a minimum small amount to a 

maximum small amount (see Figure 1) and the ribeye muscle is slightly firm.

(3) The youngest carcasses in the most mature group included in the Commercial grade have 

hard, white chine bones and the outlines of the cartilages on the ends of the thoracic vertebrae are 

barely visible, the rib bones are wide and flat, and the ribeye muscle is dark red and coarse in 

texture. The range of maturity in this group extends to include carcasses from the oldest animals 

marketed. The minimum degree of marbling required increases with advancing maturity 

throughout this group from a minimum moderate amount to a maximum moderate amount (see 

Figure 1) and the ribeye muscle is firm.

(f) Utility. (1) Depending on their degree of maturity, beef carcasses possessing the 

minimum requirements for the Utility grade vary in their other indications of quality as 

evidenced in the ribeye muscle. Carcasses within the full range of maturity classified as beef are 

included in the Utility grade. Thus, five maturity groups are recognized. Minimum quality 

requirements are described for three of these groups -- the first or youngest, the third or 

intermediate, and the fifth or the most mature. The requirements for the second and fourth 

maturity groups are determined by interpolation between the requirements described for their 
15

adjoining groups.

(2) Carcasses in the first or youngest maturity group range from the youngest that are eligible 

for the beef class, to those at the juncture of the first two maturity groups, which have slightly 

red and slightly soft chine bones and cartilages on the ends of the thoracic vertebrae that have 

some evidence of ossification. In addition, the sacral vertebrae are completely fused and the 

cartilages on the ends of the lumbar vertebrae are nearly completely ossified. The rib bones are 

slightly flat and the ribeye muscle is slightly dark red in color and fine in texture. In carcasses 

throughout the range of maturity included in this group, the ribeye muscle is devoid of marbling 

and may be soft and slightly watery.

(3) Carcasses in the third or intermediate maturity group range from those with indications of 

maturity barely more advanced than described as maximum for the Standard grade, to those with 

moderately hard, rather white chine bones and with cartilages on the ends of the thoracic 

vertebrae that show considerable ossification but the outlines of the cartilages are still plainly 

visible. In addition, the rib bones are moderately wide and flat and the ribeye muscle is dark red 

in color and slightly coarse in texture. The minimum degree of marbling required increases with 

advancing maturity throughout this group from minimum practically devoid to maximum

practically devoid (see Figure 1) and the ribeye muscle may be moderately soft.

(4) The youngest carcasses in the fifth or oldest maturity group have hard, white chine bones, 

and the outlines of the cartilages on the ends of the thoracic vertebrae are barely visible, the rib 

bones are wide and flat, and the ribeye muscle is very dark red in color and coarse in texture. 

The range in maturity in this group extends to include carcasses from the oldest animals 

produced. The minimum degree of marbling required increases with advancing maturity 

throughout this group from a minimum slight amount to a maximum slight amount (see Figure 1) and 

the ribeye muscle is slightly firm.

(g) Cutter. (1) Depending on their degree of maturity, beef carcasses possessing the 

minimum requirements for the Cutter grade vary in their other indications of quality as 

evidenced in the ribeye muscle. Carcasses within the full range of maturity classified as beef are 

included in the Cutter grade. Thus, five maturity groups are recognized. Minimum quality 

requirements are described for three of these groups -- the first or youngest, the third or 

intermediate, and the fifth or the most mature. The requirements for the second and fourth 

maturity groups are determined by interpolation between the requirements described for their 

adjoining groups.

(2) Carcasses in the first or youngest maturity group range from the youngest that are eligible 

for the beef class to those at the juncture of the first two maturity groups, which have slightly red 

and slightly soft chine bones and cartilages on the ends of the thoracic vertebrae that have some 

evidence of ossification. In addition, the sacral vertebrae are completely fused and the cartilages 

on the ends of the lumbar vertebrae are nearly completely ossified. The rib bones are slightly 

wide and slightly flat and the ribeye muscle is slightly dark red in color and fine in texture. In 

carcasses throughout the range of maturity included in this group, the ribeye muscle is devoid of 

marbling and may be very soft and watery.

(3) Carcasses in the third or intermediate maturity group range from those with indications of 

maturity barely more advanced than described as maximum for the Standard grade, to those with 

moderately hard, rather white chine bones and with cartilages on the ends of the thoracic 

vertebrae that show considerable ossification but the outlines of the cartilages are still plainly 

visible. In addition, the rib bones are moderately wide and flat and the ribeye muscle is dark red 

in color and slightly coarse in texture. In carcasses throughout the range of maturity included in 

this group, the ribeye muscle is devoid of marbling and may be soft and watery.

(4) Carcasses in the fifth or oldest maturity group have hard white chine bones and the 
16

outlines of the cartilages on the ends of the thoracic vertebrae are barely visible, the rib bones are 

wide and flat, and the ribeye muscle is very dark red in color and coarse in texture. The range in 

maturity in this group extends to include carcasses from the oldest animals produced. The 

minimum degree of marbling required increases with advancing maturity throughout this group 

from minimum practically devoid to maximum practically devoid (see Figure 1) and the ribeye 

muscle is soft and slightly watery.

(h) Canner. The Canner grade includes only those carcasses that are inferior to the minimum 

requirements specified for the Cutter grade.

§54.107 Specifications for official United States standards for grades of carcass beef 

(quality -- bullock).

(a) Prime. For the Prime grade, the minimum degree of marbling required is a minimum 

slightly abundant amount for carcasses throughout the range of maturity permitted in the bullock 

class. The ribeye muscle is moderately firm and, in carcasses having the maximum maturity for 

this class, the ribeye is light red in color.

(b) Choice. For the Choice grade, the minimum degree of marbling required is a minimum 

small amount for carcasses throughout the range of maturity permitted in the bullock class. The 

ribeye muscle may be slightly soft and, in carcasses having the maximum maturity for this class, 

the ribeye is moderately light red in color.

(c) Select. For the Select grade, the minimum degree of marbling required is a minimum 

slight amount for carcasses throughout the range of maturity permitted in the bullock class. The 

ribeye muscle may be moderately soft and, in carcasses having the maximum maturity for this 

class, the ribeye is slightly light red in color.

(d) Standard. For the Standard grade, the minimum degree of marbling required is a 

minimum practically devoid amount for carcasses throughout the range of maturity permitted in 

the bullock class. The ribeye muscle may be soft and, in carcasses having the maximum 

maturity for this class, the ribeye is slightly dark red in color.

(e) Utility. The Utility grade includes only those carcasses that do not meet the minimum 

requirements specified for the Standard grade.