Why does a dairy cow produce milk?
All female mammals produce milk once they have given birth to feed their young. All cows produce milk after they have given birth to a calf. Dairy cows have given birth to calves. So they produce milk. Over the years, farmers discovered that some cows produced slightly more milk than other cows. They kept those cows around along with their daughters as well as the bulls that sired them. Those bulls mated with not only the farmers cows but also with the farmer’s neighbors’ cows. As a result, the cows that produced the most milk became the mothers of the cows that stayed around the dairy. So the cow at the dairy produces enough milk for her calf and a whole lot more besides.
