Which baby nipples do you find your puppies like the most? Do you use newborn or nipples for older babies?

I have tried both Gerber and Aventis for newborns and find the puppies get frustrated with them.

It depends on the age of the pups. I use a newborn or slow flow for brand new babies so that that they aren't as likely to aspirate the formula. As they get older, I go to a more freely flowing nipple. Thank goodness I haven't had to bottle feed enough to have developed a favorite brand.