How are cows selectively bred?

A cow is analyzed by her conformation, her milking ability, mothering ability, calving ease, and her ability to wean a good-sized calf. The history of the calves she raised or that have grown into cows are also analyzed. Then the producer makes a decision of what kind of bull to use on her to improve her progeny that may replace her in the future. Bulls are selected based on their EPDs and their conformational qualities that should be better than hers. The calf that she produces should be one that has superior characteristics to her own, making it one that will be better for producing future generations.