Dog Food Question?

I have a 35kg puppy that was born on the 1st of June making him about 8 and half months old. <br>He is Half American Bulldog One Quarter Akita One Quater Ridgeback. <br><br>I have been feeding him on Large Breed dog food up untill now, I have started to wonder do I need to move him up on to Giant Breed dog food. <br>He's feed on a mix of Hills Large Breed, Clinivet and Chudley (English working breed dog food), but I have been looking on moving him on to Royal Canine Giant as it is formulated for dogs with Adult body weight over 45kg +. <br>Basicaly since my puppy is a mix I dont no what his adult weight will be and am a bit confused at what I should do, keep him on the same food or move him to giant breed. <br><br>I have asked at the vets and they said he shouldnt stop growing untill about 1 year 18months at about an average of 2to3kg weight gain per month untill then. If my calculations are correct that means his adult weight will be about 53kg+ 0_o (slightly scary XD.<br><br>Anyway just wondered what you would do?