On most farms in the very early 1900’s farms kept one or two bulls to inseminate their whole herd. Farmers would personally take the bulls out to pasture with the cow in heat and advise the process. At that time farmers were unaware of inbreeding the diseases associated with it causing many casualties in their herds. Unlike today, farmers worried solely about their cows producing milk and bred for that purpose and that purpose alone. In the 1930’s the Holstein Association sent out letters to farmers around the country asking them to track their bulls and the milk production of their offspring. The trend of evolution and natural selection was becoming noticed within the breed and after 5 years of information gathering from around the country the Holstein Association created bull records (now called proofs) to help farmers breed according to the bulls daughters and phenotypes. These records were used by farmers to select which of their bulls to use on different cows, still unable to get semen without the bull being at their farm. The artificial insemination (AI) industry has had a tremendous impact on genetic improvement of the breed. Since perfection of the semen freezing process in the late 1940's, AI has allowed the use of superior, proven bulls by Holstein breeders across the country. Today, AI accounts for 85 percent of Holstein births. AI made the development of reliable, unbiased methods to evaluate Holstein genetics possible. With AI, a single Holstein bull can sire as many as 50,000 daughters. Type and production information on all these females makes it easier to predict performance of future offspring and evaluate the quality of genetics transmitted from sire to offspring. Genomic Selection is a new technology that helps the dairy industry evaluate bulls on the basis of their DNA profile, allowing breeders to predict, among other things, which animals are going to give higher milk yields in a much shorter time period than previous methods. Within just the past 5 years researchers have discovered different genetic components of phenotypic variation that facilitate stable changes in production, fertility and health through selection. Genomics are used to breed for milk productions, show cattle, and bring back lost dominant traits in offspring.