Milk powder

Marcus was fed Anmum in hospital after birth. I have never heard of anybody giving Anmum infant milk powder. However, during that month the hospital was using Anmum. The month before it was Frisolac. I wanted to change the formula milk but thought better of it as my baby son is tolerating this milk well. So, I continued giving Anmum to him till recently. I have read about S26 and Nan in my uni classes. I think they are the oldest brands of formula milk around. I saw Nan while shopping in Cold Storage and on impulse decided to buy it. I have just started Nan on Marcus. He seems to like it. In fact, he loves it so much, he wanted more. He finished the milk quite fast and was crying when he finishes it. So, I made an extra 1.5oz. He finished those too.
I actually like the texture of Nan powder as compared to Anmum. Nan powder is very fine and doesn't easily clump together after I scoop it out and store in a smaller container. I am very satisfied with Nan. However, will wait for another 10 days to see if Marcus is tolerating this milk well. I read in an allergy book that once you introduce something new in a diet to a child you should wait for about 2 weeks to see if he is allergic to that food.