I only feed grains occasionally, right now I have some oatmeal treats that Rocks adore
It isn't that some dogs don't do well on grains but that it isn't really part of the natural diet. So it should be fed in limited amounts. However whatever is working for you and your babies is what counts.
Dr. B does say to make sure to give your babies Brewer's yeast and Kelp to help take care of trace minerals in the body. This is if the person is feeding a good amount of grains. If you are feeding grains everyday I would take a look into that
There are lots of threads on grains and oatmeal if you wanna do a search to find out more stuff