When it comes to evaluating beef steers, there are six criteria that must be taken into account. These include musculature, degree of finish, capacity for growth, structural correction, balance and size of the structure, and the quality grade of the meat. All of these factors are used to determine the quality of the meat, which is based on tenderness, juiciness, flavor, maturity of the carcass, firmness and texture of the lean meat, and the amount and distribution of grain within the lean meat. The most important factor in determining the quality grade is veining, which is the mixture or dispersion of fat within lean mass.
Graders evaluate the amount and distribution of veining in the steak muscle on the cut surface between the twelfth and thirteenth ribs. Each degree of veining is divided into 100 subunits. In addition to veining, other ways to assess muscle quality include firmness, color and texture. The degree of veining is combined with the degree of maturity to obtain the final grade of quality. As the animal matures, its muscles change in color and texture.
The minimum vetted score requirements for USDA quality ratings within each final maturity group are Abundant (AB%), Moderately Abundant (MAB%), Slightly Abundant (SLAB%), Moderate (MD%), Modest (MT%), Small (SM%), Lightweight (SL%), Traces (TR%) and Practically Devoid (PD%).
Musculatureis judged by assessing the amount and distribution of muscle tissue in a carcass. The more muscle tissue present in a carcass, the higher its musculature score will be.
Degree of finishis judged by evaluating the amount of fat cover on a carcass. The more fat present on a carcass, the higher its degree of finish score will be.
Capacity for growthis judged by assessing how much potential a carcass has for further growth. The more potential a carcass has for further growth, the higher its capacity for growth score will be.
Structural correctionis judged by evaluating how well-proportioned a carcass is.
The more well-proportioned a carcass is, the higher its structural correction score will be.