Have you ever wondered why cows give us their milk, even when their offspring no longer drink milk? The scheme of lactation in large horned animals is the same as in all existing mammals – it begins only after the appearance of offspring.
Milk is produced to feed the emerging calf. But if you milk the cow constantly, then the milk will not disappear for a very long time, since the body of the horned mother “considers” that it is necessary for the child. And long-term breeding did increase the milk yield by a couple of times.