This is a loaded question, but here goes:
* Early maturing - reach puberty by 12 to 14 months of age
* First calf by 22 to 24 months of age
* Calve unassisted every year
* Raise a calf that could either be used as a replacement or, if it is a male calf, produce an acceptable carcass
* Become pregnant early in the breeding season
* Wean a calf every year
* Produce enough milk in the environment that she is asked to survive in
* Be able to do all the above without much supplementation
* Have a good disposition; deep body; and sound feet, legs, udders, and teats
* Stay in the herd for a long time - 10 plus years