Implementation of the Canadian retail cut beef yield grades

As a means to facilitate North American cross-border beef trade, Canada is adapting its grading system from
a three class total lean yield (TLY) to a five class retail cut yield (RCY). The relationships and implications of this transition from total lean meat yield to a harmonized retail cut yield provide important historical grading benchmarks. The aim of this study was to interpret the relationships and implications of the transition from TLY to RCY yield estimations and to adapt the traditional Canadian grading system of three TLY classes to a new system of five RCY classes.
A total of 720 beef carcasses were used first to determine the relationship between the United
States Department of Agriculture (USDA) and Canada-TLY systems and then develop a modified grade ruler,
harmonizing the Canadian grades into five classes similar to the USDA-RCY grades. Additionally, the developed RCY matrix was validated with a population of 750 carcasses from three Canadian beef plants with capabilities for Camera Vision Systems RCY evaluations. The predictive ability (R2, RMSE) was evaluated using SAS 9.4 (2014). Carcass weight (192.2 – 536.4 kg), grade fat (2.0 – 32.0 mm), rib-eye area (52 – 124 cm2), estimated lean yield
(42.5 – 65.6 %), USDA-RCY (45.1 – 55.3 %) and marbling score (220 – 710) values of the carcass population used in the present study were within the actual range of the Canadian beef carcass market (Canfax 2018). The prior three-class TLY grade system in Canada was based on the percentage estimation of the total carcass lean. Harmonization with the USDA-RCY resulted in the classification of carcasses into five retail yield classes defined by the percentage of closely trimmed (0.5-inch fat, or less) and boneless retail cuts from the four major primal cuts (chuck, rib, loin, and round) derived from a carcass. The relationship between the Canada-TLY and the USDA-RCY fit a linear regression model with a considerably high regression coefficient (R2 = 0.80; RMSE = 0.8472; P < 0.0001). By considering both the regression model and the breakpoints for the five classes of the USDA-RCY, a matrix of the estimated RCY percentage was developed and implemented into the Canadian grading ruler, characterized by four muscle scores and fifteen fat classes
(Jones et al., 1991). The validation of the adapted Canadian Grade Ruler, including the Retail Cut Yield grade matrix against the Camera Vision Systems Retail Cut Yield estimations showed R2 values between 0.60 - 0.75.
Yield grade evaluations using the Grade Ruler are still required in beef plants where camera technology has
not been implemented, or only partially introduced. Regression analyses of the Canada-TLY and USDA-RCY showed a strong relationship (R2 = 0.80) in a research population. A successful adaptation of the Canadian grade ruler to a Canada-RCY percentage matrix with five yield class breakpoints (Canada 1 – Canada 5) was carried out. The adapted Canadian grade ruler is an accurate and reliable grading tool and can be implemented where camera technology is absent to provide harmonization between Canadian and USDA yield estimations, facilitating cross border beef trading.