Cow milk and weight related. Gain?

My son who is 23 months old doesn't drink milk at all. He is on breast-feed and solid food. He is not allergic but hates the smell of milk and has rejected curd, paneer, buttermilk, raita. He has had Malpua (dessert), sweet curd (store bought) and lassi all but in little qty. Because of this, I am wary of weaning him off the breastfeed yet and also worried about his calcium consumption. He loves banana and some other fruits though. What should I do to make him drink milk? Is there any other alternative to cows milk? Also, he is 11.3kgs right now and on the leaner side. Friends and family say he should be more chubby at this age. Should I really work upon his weight gain? He is otherwise active and a happy child but a very very fussy eater.