Your bird looks like a homer or roller to me. The earliest I wean these birds is 28 days old. That's kinda early for them, when being raised by the parents, but being hand raised 28 to 31 days old is average. I have been breeding and raising pigeons for about 6 years now,(and I'm only 15!) It happens a lot where there is a day diffrence in the hatch date of nestmates and the littler one dies, it happens to me all the time. Mashed up chicken pellets/mash with warm water is what I would feed.
Good luck with the little guy, your doing a great job!
Taylor
P.S. Your oldest son is cute!
Good luck with the little guy, your doing a great job!

Taylor
P.S. Your oldest son is cute!