Why do cows continuously make milk when humans can only do it after giving birth?
Cows don’t do it continuously; they too have to give birth periodically to calves to keep the milk flowing. Where do you think all those steers and heifers come from for the steaks and hamburgers that you eat? The milking process keep the milk flowing artificially, but it doesn’t last indefinitely; the cows have to be artificially inseminated periodically and give birth to keep the dairies in business.
