>>I have a lot of uncooked brown rice that my family uses for eating and I was wondering if I could give my Uro some rice in addition to lentils and peas? Is there anything I should be concern about?
Not flaming anybody, but that is a myth.(see below link)
Rice for uros, is reasonably okay, just not a staple. Variation in diet is a great thing for these guys, just keep in mind the size, and nutritional input of certain foods.

http://www.snopes.com/critters/crusader/birdrice.asp