There are numerous carcass traits that have heritability estimates that will move the beef product in the desired direction of the consumer. Some of the major traits are carcass weight, ribeye area, fat thickness, marbling, percent retail product, retail product weight, fat trim, fat trim weight, percent bone, bone weight and the Warner-Bratzler shear force test. The selection for each of these products starts with the cow herd and sire selection. Basically it is impossible for progress of any kind to be made unless there is a live calf. Nutrition plays a major role in reproductive efficiency.
Nature dictates a specific priority for the utilization of nutrients by the beef cow.
Body maintenance is the first natural requirement met by producing females. This is followed by the requirement for lactation, then the demand for reproduction is last. Reproduction may be looked on as a trait that is strictly luxury only if nutrition is adequate. This is the reason it is so important to maintain adequate nutrition for the cow herd. Multiple trait selection maintains a balance in the genetic input for developing and maintaining future replacements.