Hi, Thanks for selecting the forum. It's too early to start cow's milk for this child. Don't give cow's milk until 2 years of age because of it's inferiority when compared to human milk or formula milk. Atleast until 1 year give human milk or formula milk only without any options. My suggestion for your resistant child is just perseverance and nothing else. You didn't mention that your baby developed any allergy to any of the formulas used. Hence, don't succumb to your baby's resistance. If the baby is really that bad(which should not be the case), try different formulas available in the market which will give a variety but the child runs a risk of getting stomach upsets with varieties. In the worst case scenario, try a pinch of fine sugar at the tip of the teat of the bottle when you start feeding, but the baby runs a risk of developing a sweet tooth for everything and be prepared for it :-)Decide on what you or what your baby wants, but my first suggestion is perseverance, if given no furthur options baby will accept whatever given. Regards, Dr.Pravin Asir.