My DS was b/f for a very short time and then f/f till 12 months. I introduced cow's milk into his formula for a few weeks before offering 100% cow milk but he just didn't like it. I made sure he ate 2-3 servings per day of dairy after that, but he just never warmed up to cow's milk unless it was on cereal. Even now at 32 months, he still won't drink milk even from a cup.