Cows produce the majority of milk consumed by people. They are able to consume feed sources not fit for human consumption and produce. They are capable of producing vast quantities each cow produces about 2,500 gallons per year, or 8 gallons per day. Historically, cows have been the most valuable domesticated animal, both economically and as a reliable source of nutrition.
Dairy cows are generally milked twice a day. They are herded through a dairy shed that slowly narrows until they are single file. The cow is then allowed to enter a milking platform designed with individual stalls. The platform slowly rotates to allow for the farmer to attach the milking machines to each cow and inspect her health. The cows utters are inspected for mastitis at this point in order to treat and prevent bad milk from being introduced to the holding tank. They are also fed at this time. The automated system allows for very little contact with the cattle reducing their stress which stimulates milk production. The milking machines pump the milk from the cow into a refrigerated storage tank (kept at 4⁰C) before a tanker truck comes and takes it to be pasteurized.