I am a little fuzzy on it since it has been a long time since I thought about it, but my father-in-law was a Holstein-Friesian breeder. If I recall correctly the Holstein breed association requires pedigrees to start the farm name. Then you usually include the name of a prominent ancestor in the blood-line, and a name to distinguish the individual. So if you are in the know, you can tell a lot about an animal from the name.
My father-in-law used to get hours of joy from poring over semen catalogs. You know those really intense baseball fans that dig through page after page of player statistics, and quote them from memory to anyone who will listen? Translate that to dairy animals, and that was my father-in-law. The catalogs were full of tables of production records of each bull's progeny. He had two semen storage freezers for his speculative acquisitions. (Basically, insulated tanks cooled by liquid nitrogen. The milk hauler carried liquid N so that he could top off the farmers' semen storage as he pumped their milk into the truck.)
In the old days, you were paid by the total production with a butter-fat premium for richer milk. Then at some point they reduced the butter-fat premium but added a new premium for protein content. That caused a major reshuffling of the value of many bulls.