His weight is just above the 10th percentile for his age. For him to start drinking milk, he may have to be weaned off breast milk. When you start to wean off the breast milk suggest try mixing ¾ breast milk with ¼ regular milk and see if he accepts and tolerates it. If he does, then after a week or so, try doing a mix of ½ breast milk, and ½ regular milk. Gradually go to a mix of ¼ breast milk and ¾ regular milk then totally to all milk. Is he eating other foods and does not like fruit? If that is the case, then you can blend it in the milk as a shake or mix it in yogurt and see if he will accept it that way. Hope that helps you.