I start off my puppies on Royal Canin. They have a weaning/starter food for 4 week old puppies to start weaning. I wait until they are about 5 weeks old to start weaning. I then switch to the RC #32. The Canidae GF/ALS does not recommend until 2 months old. I stay with the RC until my pups are 6 months old then switch to the Canidae GF and I am using the Bison/Lamb since this is the only one that does not have any chicken or chicken meal in the mixture. The other 3 types of Canidae have that.