Large breed puppy - should he be weaned onto large breed dog food?

[sedders001]

I have just purchased a Leonberger puppy (now 10 weeks old) and whilst he is great I am a little concerned that as a large breed dog he had been weaned onto a normal puppy biscuit ....
I was under the impression with some large breed dogs that this encourages them to grow too quickly and can lead to joint problems later in life?
He also doesnt seem to chew this small biscuit at all and doesnt have much of an appetite for them.  Dont get me wrong he put 1.7kg on in a week when we got him! - and he is beautifully formed (not fat - not underweight - but nice and well proportioned)
I was wondering if any other large breed owners could offer any advice?

[lookingfornewf]

It was recommended to me to feed my Newfie adult food right away and he has done very well on it. He still seems to be growing fast enough to watch it happen, but isn't fat and is very healthy.
Please, please post pictures of your puppy. Leonberger pups are always sooooooo cute.