We did the same as Rod, planted what we call "cat grass" in a few pots out back, and Brooky munched on that all day. It has stopped her eating grass on our walks which I am sure is loaded with sprays and chemicals...grass from our local park always made her bring it back up, I imagine from fertilizer or something. Now she has safe pits of grass to munch on

Brooky is on a raw diet, but does fine with some grains like rice. I think every animal is different just like us humans (I.e wheat makes me sick, but if my husband doesn't eat it he looses so much weight and doesn't feel well)...so each their own. Unless there is an allergy, a small amount of good quality grain I don't see being an issue