Marbled meat

Beef quality grades - are based on a composite evaluation of the degrees of (1) marbling and (2) maturity.

Because the chronological age is virtually never known, physiological maturity is used; the indicators are bone characteristics, ossification of cartilage, and the color and texture of ribeye muscle.

Cartilage and bone maturity receives more emphasis because lean color and texture can be affected by other postmortem factors.

[1] Beef yield grades - estimate the amount of boneless, closely trimmed retail cuts from the high-value parts of the carcass–the round, loin, rib, and chuck.

Prime, Choice, Select and Standard grades commonly come from younger cattle (under 42 months of age); Commercial, Utility, Canner and Cutter are applied to older cattle carcasses which are not marketed as wholesale beef sides or blocks, and are used in ground products and for cheaper steaks in family chain restaurants.