When we bred & raised Golden Retrievers we started them at 3 weeks old on puppy food mixed w/warm water to make it a mush. They sure made a mess! We started them early because 10 pups was too much for the mother to handle & we could see it was wearing her down. She weaned them herself by 4 weeks old.
We had a litter of Australian Shepherd pups 2 years later & I started them on the same sort of food between 3 - 4 weeks old. Momma had a smaller litter of 5, but when those pups get teeth & are nursing every time momma lays down teats get sore & mothers get nippy.
Add warm water to the puppy food. Let it sit until it's mush then add a little more water to make it soupy. The first few days the pups will have no idea how to eat so they'll slurp it. Feed them on papers because they WILL make a mess, & be prepared to wipe feet & muzzles. Gradually cut back on the water over the next 3 weeks or so until they can eat the hard food.
at 9:42 AM on Jul. 1, 2010