Japanese Carcass Grading Standards

The grading of meat animal carcasses is managed by the ‘Japan Meat Grading Association’, in the meat wholesale markets and at the meat centers established in major producing areas, throughout Japan.

The grading is implemented according to the carcass grading standard for beef and pork, established by the association, under the approval by the director of the Animal Industry Bureau, the Ministry of Agriculture, Forestry and Fishery (MAFF).

Grading of carcasses plays an important role in the establishment of appropriate prices for production and for the rationalization of distribution channels.

1. Yield Score

Yield score is determined by estimating percentage by the multiple regression equation, which includes four carcass measurements. Most measurements are obtained on the 6th to 7th rib section, as shown in the figure of ribbed carcass. Rib eye area is measured by grid and others are by scale. An additional measurement for the equation, the left side weight, is obtained from routine records.

Equation for Yield Estimation
 

Note: Add 2.049 for Wagyu carcass

Yield score may be reduced by one rank, if the inter muscular fat thickness is rather thick compared to the left side weight and rib eye area or if round is too thin and the proportion of fore and hind quarters is apparently undesirable.

Classification of Yield Score
 

Yield average value is determined so as to normally distribute around B rank.

Carcass Measurements on the 7th to 7th Rib Section

2. Meat Quality Score

Meat quality score is determined in terms of beef marbling, meat color and brightness, firmness and texture of meat, color, luster and quality of fat.
 

a. Beef Marbling

According to the results of a market survey on carcass distribution by the degree of marbling, the majority were classified in the range of “1- to 1”. This range was regarded as “Grade 3” and about 40% of marketed carcasses were included in this grade. Then, beef marbling was divided into 5 grades so as to center around the “Grade 3”. As a result of this revision, the minimum requirement of beef marbling for each grade is more fairly rearranged than in the previous grading system. In the new grading standard, twelve standards of  Beef Marbling Standard (BMS) showing continuous change of the degree of marbling are adopted.

Average Beef Marbling (Grade 3)


Classification of Color and Brightness Grade
 

b. Color and Brightness of Meat

In this item, the meat color is evaluated by prepared as seven continuous standards. Average color range is from No. 1 to No. 6 of BCS No. and carcasses in this color range can be graded in “Grade 3” or upper grades. Brightness of meat is evaluated by visual appraisal. At the final decision of grade of this item, both factors are considered.

Average Meat Color Range (Grade 3 and above)


Classification of Color and Brightness Grade
 

c. Firmness and Texture of Meat

For this item, two factors are evaluated by visual appraisal and they are classified into five grades. At the decision of the final grade of the item, both factors are considered.

Average Firmness and Texture of Meat (Grade 3)


Classification of Firmness and Texture Grade
 

d. Color, Luster and Quality of Fat

One of the factors in this item, fat color is evaluated by Beef Fat Standard (BFS) prepared as seven continuous standards. Average color range is from No. 1 to No. 6, and carcass in this color range can be graded as “Grade 3” or upper grades. The remaining two factors, luster and quality are evaluated simultaneously by visual appraisal. Three factors are considered in the decision of the final grade of the item.

Average Fat Color Range (Grade 3 and above)


Classification of Fat Color, Luster and Quality Grade
 

3. Determination of Overall Meat Quality Score

Overall meat quality score is graded down to the lowest grade amongst the four item as follows:
 

4. Stamping of Yield and Meat Quality Score on Carcass

Final yield and carcass quality scores are indicated on carcasses by one class of the 15 combinations.
 

5. Damage Indication by Superscript Stamp

A carcass which is recognized to have any damage is stamped with a superscript mark classified according to the type of damage.

Example of a Damage Indication


Classification of the Type of Damage
 

6. The Expected Effects of the New Beef Carcass Grading System

• By the introduction of yield score, a carcass which has high yield will be valued properly. Excess fat will also be controlled at the production stage.
• Meat quality score, having been the most important value standard are rearranged for beef marbling and the other related items. As a result, excessive consideration on the degree of marbling will be controlled.
• By the introduction of yield score and the moderation of meat quality score, economical beef production, adjusted to each breed's ability, should be promoted.
• The standardized ribbing, unified throughout the country, will result in more objective carcass classification and more rational marketing of carcasses and prime cuts, reflecting the different demand of each region more precisely.
• In the old grading system, standards for beef color and fat color were not objectively defined. Newly introduced Beef Marbling Standard (BMS), Beef Color Standard (BCS) and Beef Fat Standard (BFS) have given additional objectivity for grading.
• The improved standards, combining yield and quality of carcasses into 15 classes, will facilitate the choice of carcass to correspond to various demands.