Maximum milk without supplying adequate feed can mean a reduced conception rate. Producers must decide the desirable range of EPDs that will fit within their feed and forage environment. Frame and Muscle USDA Feeder Calf Grades are based on frame and muscle scores. Frame size provides an estimate of rate of maturity, mature size and carcass cutability at a given liveweight. Frame size is generally appraised visually by bull buyers or measured in terms of hip height adjusted to a standard age.
Some breeders provide adjusted hip height or frame score on their sale bulls.
Larger framed steers gain more efficiently and are leaner than small framed steers at a given weight. Packing plants discriminate against carcasses that are too light or too heavy. For these reasons feeder calves that are at the upper end of USDA Medium or the lower side of USDA Large generally bring the best prices. While larger framed market animals may be preferred, larger framed females in the herd may reach sexual maturity later and require more feed for maintenance. Increasing frame size in the cow herd without increasing the level of nutrition will generally result in a decline in reproductive efficiency.