it depends on what the parents decide to offer their child.......I personally do not feel right offering the milk of another species to my human nurslings....my babies continued to nurse till self wean and did not drink cow milk.
But, a little history into this.....my first nursling was given cow milk starting at a year because that is what I was told to do and I didn't know any better. She did NOT tolerate it well. I began researching milk/meat and vegetarianism. I made a decision promptly to become veggies and ban the cow milk. Haven't looked back in 8 years.
My second child has never drank cow milk in her 3.5 years and neither will her newborn sister.
We do use milk substitutes for cereal, cooking and baking or whatever.......such as coconut milk, almond milk, rice, cashew etc.....we used to drink soy but I no longer purchase it.
They certainly don't require cow's milk, but they can have it if they like; it's just another food.
Yes. I nursed our babies until they were 3 years of age and they also used a sippy cup to drink milk. Your family doctor can help you figure all of this out.