The »white stuff« is his actual skin! It is covered in yellow/orange scales (dead skin) which flake off and are being replaced.
On the picture it sure does look like he'd broken his middle toe once, but it also looked healed somewhat. Does his foot feels warm to the touch? Warmer than the other one?
Check the area around his toe-nail for infections! Maggie, one of my Magpie ducks is limping for weeks and yesterday i finally figured out that her toe-nail is infected. Hard to see on a black duck-foot, but she squeaked yesterday when i touched her toenail. And she felt much better after applying Triple-Antibiotics
with pain killer.
My four white layers also have more or less bad bumble-foot, but don't seem to have any pain, so i missed it.
Bazilla collapsed with fever-cramps on Thursday evening and i had to cool her down for ~2 hours in a bowl with garden-hose cold water. She is doing fine, and i am focusing on her for now, Blanca and Earthquack don't like to be treated and boy they are strong and know how to use their toenails. My arms look like i robbed through barb wire…