For the breeds reporting carcass EPD the range in marbling for the highest and lowest individual is a little over one U.S.D.A. degree. That same relationship holds for other carcass factors. For commercial breeders fastest improvement can be made by introducing a breed noted for high expression of whatever trait is involved. But be careful to understand what other changes might accompany a change of breeds. A combination of moderate performance levels is often most beneficial in commercial production.
Many factors affect carcass merit.
Note that genetics is only one factor. And new technology is sure to be available. Let us return our attention to the four problem areas of beef acceptability under some genetic influence. And in the process of moderating size cow herd utility and adaptability could be improved. Yes, very effectively.