C.E.
i fed my son all kinds of foods starting at 6 months of age. It's just based on what he likes and isn't allergic to. I started off buying the ones that are made especially for babies. I believe they are even organic. Simply give them to him on a day with foods you know he isn't allergic to. This way if he has an allergic reaction then you know its the yogurt. But I say go ahead.
good luck