I thought so about the person who told me this a few years ago. The implication that milk is natural I find particularly ironic.
Milk is provided by one's mother for nourishment during the pre-weaning years.
Mother rats provide milk for baby rats. When baby rats grow up, their bodies no longer require milk, and they are weaned. Mother giraffes provide milk for baby giraffes. When baby giraffes grow up, their bodies no longer require milk, and they are weaned. Mother pigs provide milk for baby pigs.