The Canadian Bison Grading System- How it Presently Works

Don Clarke, Grading Supervisor
Canadian Beef Grading Agency

Reprinted from Smoke Signals, February 2001
This information was originally presented at the CBA Annual Convention in November, 2000


A new system for grading bison meat was developed by the bison industry in the 1990’s. It has been a great help for the bison meat marketers as it allows them to ensure a quality product is sold to their customers. It is based on the beef grading system but it takes into account some of the inherent differences of a bison carcass.

The first bison grading system was developed in the late 50's and early 1960. Tentative grades came into effect on March 21, 1960. Four grades of bison were established.

  • Canada Choice Buffalo
  • Canada Good Buffalo
  • Canada Utility Buffalo
  • Canada Manufactured Buffalo

The grade names and standards were the same as beef at the time. Tentative regulations were never approved or Gazetted which means they were never officially recognized or applied. Attempting to relate inherently different bison carcasses to regulations designed for beef grading proved to be their downfall. This system was used very little if at all.

The reason for developing new regulations:

  • The Bison industry developing and growing rapidly.
  • Grading will assist in providing a consistent product to the purchaser.
  • It also provides a marketing advantage over competing countries.

During the February 1990 Canadian Bison Association's annual meeting, a Bison Grading committee was formed, with a mandate to develop a bison grading system.

The committee was composed of representatives from the Peace Country Bison Association, Agriculture Canada and the Center for Agriculture Diversification Northern Lights College. On March 28th 1991 a Bison grading pilot project was established to have bison carcasses evaluated based on a set of criteria established by the committee. Results were analyzed and presented to the committee on February 14,1992. The committee then developed the proposed grading system criteria. This criteria was presented to the Canadian Bison Association on February 28th. After a few amendments the standards received unanimous national approval by the Bison industry and was implemented on an unofficial basis in April of 1993.

Official grading began on February 28, 1995. Regulations amended effective March 1, 1995. On the basis of these standards the European Economic Community approved the importation of bison into Europe.

There are 9 grades, which are Al, A2, A3, B1, B2, C1, C2, Dl, D2. Grading characteristics evaluate: maturity, muscling, meat quality and fat measurement.


Bison Carcass Grading Regulations:

Part of the Livestock and Poultry Carcass Grading Regulations Factors in Bison Grading:

The main factors used to determine the grade of a bison carcass are: maturity, muscling, colour of fat and lean and fat cover.


The maturity or age of a bison is an important factor in the classifying of bison into the various grades since there is a direct relationship between tenderness and maturity.

Determination of Maturity:

The grader must be able to determine the sex and relative maturity in order to know the class of carcass he is grading.

The maturity in a bison carcass is determined by inspecting the cartilaginous caps on the 9th, 10th and 11th thoracic vertebrae immediately below the knife rib sight for not more than 50 % ossification for maturity division 1, over 50% to 80% for maturity division II and over 80% ossification for maturity division III carcasses.

Bison live linger and ossify slower than beef. Ossification occurs more rapidly in the front and slower in the hind. You may see significant ossification of the thoracic vertebrae over the neck area and very little in the hind.


Muscling, as considered in meat grading, refers to the proportionate development of the various parts of the carcass or wholesale cuts and to the ratio of meat to bone.

Determination of Muscling:

The muscling in a bison carcass is determined by using the same criteria as beef. A bison is more heavily muscled in the front and less muscled in the hind than beef. The grader must take this into consideration when making the final muscling determination.


Fat will refer to the degree of fat-covering on the out- side of the carcass, its thickness, colour, firmness and distribution.

Determination of Fat Cover:

The best fat covering is a uniform distribution of fat over the entire carcass on the outside.

For the A1 grade, the minimum fat thickness at the rib sight is 1mm. The grader should be sure this is actual fat exclusive of connective tissue to ensure the carcass had at least a light film of quality fat.

A1- 1 mm to 6 mm
A2 -Over 6 mm to 12 mm
A3 -Over 12 mm

Determination of Fat Colour:

Yellow fat is not acceptable in the A & B1 grades. It should be white to slightly tinged with reddish or amber colour. While a yellow fat cover has not been found to cause poor eating quality, it has long been associated with older mature carcasses and the trade discriminates against it.

In determining the degree of yellowness in a bison carcass, the grader should make a thorough examination of the internal fat as well as external.

Determination of Fat Firmness (texture):

The grader should learn to differentiate between good and poor quality of fat as these are factors which aid in determining the overall quality of a carcass. The ideal finish is white in colour, hard to the touch when set and a creamy texture. The opposite to this condition is a carcass which has a thin, soft covering of rubbery, oily fat of a deep amber colour.

Colour and Firmness of Lean Meat:

Colour of lean meat is a quality factor which is determined by examining the cross-section of the loin muscle 10 minutes after being exposed by knife ribbing. A and B1 grades state that the flesh should be firm and bright red in colour.

While dark-cutting meat usually has the same eating qualities as that of the bright-red colour, it is not attractive to the consumer.

Determination of Colour and Firmness of Lean Meat:

A colour standard for meat has been developed and accepted by all segments of the meat industry. To evaluate meat colour, the left side of the carcass must be knife ribbed at least 10 minutes before grading.

For uniform interpretation, this standard is to be interpreted in the following manner.

  1. If the colour of the rib-eye surface is brighter than the standard, the colour of the meat is to be considered as acceptable to be graded in the A or B1 grads.
  2. If the colour of the rib-eye surface is darker or equal to the standard, then the colour of the meat is considered as dark and is not acceptable in the A or B grades.
  3. If more than 1/4 of the rib-eye shows a discoloration equal or darker than the standard, the colour of the meat is to be considered as dark and is not acceptable in the A or B I grades.

When the colour of the rib-eye surface is borderline between dark cutters and bright red, the grader should hold the carcass and evaluate it after additional chill time or the next day. The carcass must then be fibbed on the right side at least 10 minutes before it is graded. The carcass is then graded based on the colour of the meat on the right side of carcass.

Grade Marking:

Each hammer consists of a short handle with a "T" shaped hammerhead. The grade plate is flat, square and affixed to the hammerhead (old beef hammer). The stamp plate indicates the grade and grader code. A complete set of bison grading hammers consists of nine grades: Al, A2, A3, B1, B2, C1, C2, Dl, D2. Each side is stamped five (5) times in brown ink, once on each primal cut. The carcasses are not ribbon branded.

Bison/Beef Grading Comparison:

Some of the differences between bison and beef grading regulations are:



9 grades

13 grades

Ribbed between 11 & 12 ribs

Ribbed between 12 & 13 ribs

1 mm minimum fat cover for A grades

4 mm minimum fat cover for A grades

Heavily muscled fronts

Heavily muscled hinds

3 maturity divisions

2 maturity division

More age in A grades than beef

Less age in A Grades than bison

Grade stamped in Brown ink

Grade stamped in red ink

5 stamps per side

2 stamps per side

Not ribbon branded

Ribbon branded

No marbling assessment

Marbling assessment

3 meat yield grades

Meat yield % calculation



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