Cooked grain? Yup, that makes sense.What's really weird is that my chickens love rice
The breed is Plymouth Rock (named for a particular place.)When Rocky ( My barred rock plymouth rooster )was young,
https://en.wikipedia.org/wiki/Plymouth_Rock
For one that is Barred (color), the correct form is Barred Plymouth Rock.
You can shorten it to just Barred Rock, but if you have the "Plymouth" at all, it is part of "Plymouth Rock" and not hanging out as a single word in any other random place.