chicken bone for my tortoises

by Niloofar
(Iran)

hi. i have 4 tortoises (mediterranean,i'm not sure). my baby tortoises love chicken bone (i grind it first).

i've heard that tortoises need low protein and high calcium food. but since i live in a small city, i don't have a lot of choices to provide them what they need. please tell me if chicken bone is harmful or contains protein.
(sorry if my English is not perfect).