Apparently baby refusing a bottle can stem from a few different issues. Of course the nipple of the bottle is not the same as mommy's nipple - the shape, the feeling, the flow. Baby also has a keen sense of smell and boy oh boy, baby knows what mama smells like pretty much from birth. Of course you've got all those pheromones flowing as well!
I'm pretty fascinated with a new product I came across that is trying to help with the issue of babies refusing the bottle: Mamascent. In a nutshell, Mamascent is a fabric that you place in your bra to absorb your scent and then it attaches to baby's bottle so baby smells you and picks up your comforting pheromones when bottle feeding. So simple yet brilliant!! Here's a graphic and a video on how to use Mamascent:
*Disclaimer: Although I did receive this product free of charge, I was not compensated in any other way to do this product review. All thoughts and opinions are my own and completely unbiased.