You can feed dog food for atleast first 9 months. That's the time when puppies grow rapidly. How much do the puppies weigh? Instead of Pedigree, I'd suggest you to use Eukanuba or Royal Canine.
You don't necessarily have to feed commercial food all the time to your pupppies. You can feed the following items as well:
A) Boiled eggs ( not more than one preferably in the morning )
B) Vegetables ( exclude oils and spices and feed any seasonal vegetables)
C) Curd or Buttermilk ( They help speed up digestion and good in Summers)
D) Chicken or Mutton ( exclude bones from them and serve with rice )
E) Roti and breed ( Most dogs don't show any problems but few are allergic to wheat )
The only thing that you have to bear in mind while feeding home food is that you are feeding good calcium, vitamins supplement and a good hair supplements to them. They'll meet any nutritional deficiency arising out of the home-cooked food.