M.S.
Goats milk is better than cow's milk however, everything I searched on it, also states not for infants. Likes cows milk, it can cause intestinal problems and/or anemia when given before the age of 1. Here is some info from Dr. Sears website
http://askdrsears.com/html/3/t032400.asp
I also came across many sites saying that both almond milk and coconut milk are great subsitutes. Do more research though before giving to your 9mos old (for those concerned with almond milk, I've been led to believe this is not the same as eating peanuts, so allergies shouldn't be an issue, however, I have not personally researched it). Here is one of the sites that stated what I said about coconut/almond milk http://chrysalisyog.homestead.com/milk.html but if you google coconut milk infants you can find more.
I hope you find something that works for your son,
M.