Economics and Marketing: Beef Carcass Evaluation

Take home message

• Assignment to a grade starts by assessing the maturity of a carcass.
• Most youthful carcasses fall into the A and B grades whereas mature carcasses fall into the D and E grades.
• Within the A grades, carcasses are assigned to either A, AA or AAA grades strictly on the basis of marbling.
• All ‘A’ grade carcasses are also assessed in terms of their cutability (the expected yield of lean meat).
• Youthful carcasses with some deficiencies fall into the B grades.
• Mature female carcasses grade D1, D2, and D3.
• Mature male carcasses grade E.

The current grading system as of January 2000 is shown in Table 1. By evaluating the degree of ossification of the bones, most youthful carcasses fall into the A and B grades whereas mature carcasses fall into the D grades. Carcasses from bulls or stags of any age which show pronounced masculinity fall into the E grade.

Youthful carcasses which have 4 mm of backfat, at least traces of marbling, good to excellent muscling, a bright red meat colour and firm, white to amber coloured fat qualify for the A grades. Within the A grades, carcasses are assigned to either A, AA, AAA or AAAA (Canada Prime) grades strictly on the basis of marbling (trace, slight, small, slightly abundant respectively) and as of yet, no price differential exists among the three A grades. However, all ‘A’ grade carcasses are also assessed in terms of their cutability (the expected yield of lean meat) and are assigned a yield grade (Y1, Y2, Y3) which forms the basis of payment. Lean yield is assessed using fat class and muscle scores with break points at 59%, 58 to 54% and 53% for Y1, Y2 and Y3 carcasses, respectively (Table 2).

Table 1. The Canadian Beef Grading System.


Back fat depth is measured in millimetres (mm) at the grade site and assigned to fat class in 2 mm increments (e.g. fat class 1 is 4 or 5 mm; fat class 2 is 6 or 7 mm, fat class 3 is 8 or 9 mm, etc.). Muscle scores (1-4) are determined on the basis of rib eye length and width measurements at the grade site (Table 3).

Table 2. Cutability (% lean meat yield) Estimates Based on Fat Class and Muscle Scores.


Carcasses which are youthful but have some deficiencies fall into the B grades. Hence B1 carcasses are lacking in finish (less than 4 mm of back fat) or devoid of intramuscular marbling fat. Any youthful carcass having bright red meat colour but yellow fat (generally as a result of grass finishing) will fall into the B2 grade. Youthful carcasses with bright red meat colour and firm, white to amber fat but which are deficient in muscling fall into the B3 grade. Animals which undergo prolonged stress prior to slaughter can develop a dark red (to almost black) meat colour, which results in a downgrade to B4 (traditionally known as dark cutters).

Table 3. Muscle Scores (1-4) Based on Rib-Eye Length and Width.


To qualify for the D1 grade mature carcasses must have excellent muscling and be well finished with white to amber fat. Mature carcasses with deficiencies in muscling or with yellow fat fall into the D2 grade. Mature carcasses which are deficient in muscling to the point of emaciation receive a D3 grade. Over-fat mature carcasses ( 15 mm) receive a D4 grade. Any mature or youthful carcass with pronounced masculinity will receive an E grade.

Although the grading system does not guarantee the eating quality of meat there is scientific rationale behind most of the grade factors:

• as an animal matures physiologically, the amount of connective tissue and the degree of connective tissue crosslinking increases, decreasing meat tenderness. The degree of bone ossification is an indicator of this process.
• increases in marbling have been positively associated with improvements in flavour and juiciness. Marbling only accounts for a very small amount of the variation in tenderness (3-12% depending on the study).
• carcasses with lower backfat levels can chill more rapidly causing reduced tenderness.
• yellow fat results from consuming diets with beta-carotene which is stored in the fat. Beta-carotene is not harmful to consume (it is responsible for the orange-yellow colour of carrots), however carcasses with yellow fat are visually discriminated against by most consumers.
• dark cutters result from depletion of energy stores in the preslaughter period such that the normal muscle pH decline post-mortem does not occur. Dark cutting carcasses are visually unappealing and because of their higher pH, have more rapid rates of spoilage.

For further up-to-date information on the Canadian Beef Grading System, please contact either: