If you were lucky you started life outside the womb on the perfect raw food diet(perfect for infants)...Your mother's breastmilk.
Unfortunately not everyone is that lucky. In the poorest country in the world, Sierra Leone, you are luck to get any food, and very lucky to get breastmilk. This is due in part to a cultural taboo against having sex with a nursing woman. Since the guys want to have sex breastfeeding is discouraged. When a woman doesn't breastfeed regularly her milk drys up.
In Sierra Leone when your milk drys up you don't have much else to feed your starving infant. This is the scene for the recent Salma Hayek cross-nursing(she breastfed someone else's baby)controversy.
So many people in the United States thought it was "just wrong", "gross" and "totally disgusting" for someone to breastfeed someone else's child.
You have this starving baby and a lactating woman who willing feeds the infant and people freak out about it.
Isn't it strange though that most Americans think cross-species-nursing is just fine?
When was the last time you saw people freaking out because adult humans were drinking bovine mammary secretions?