The closest to humans is actually donkey. Cows are just docile and easily bred and have many uses.
Each species of mammal makes milk perfectly suited to that species, and further, each animal makes milk specific to each baby which responds to pathogens the baby comes into contact with throughout each day communicated via saliva and the body then makes antibodies. It's literally how we form our immune system and fight off routine childhood illness.
We have so far removed from nature it's scary. And the mammalian milk production mechanism is wonderous. I had no idea until I had a baby, breastfed, and learned all this on my own.
It would be taught in schools if our society valued health and wellbeing instead of profit.