Im a stubborn, bearded, booze smelling, mean little man....i mean Dwarf!....
Subject B is a complete failure, no skill grow, no fights, just a boy and his dogs....ill leave the chamber closed and will not resupply it...maybe hunger and despair will create something salvageable.
4 new subjects, i reused C chamber, the dogs didn't left it so i just had to put another child in there, by the way, there is no trace of subject C, i think the dogs ate him...maybe it wasn't the best idea to put another child in there....what im saying? If the dogs tasted Dwarf flesh and liked it, the better, will make the following subjects more....eager to cooperate.
The new chambers are just 1x1 and it seems there is a pit limit of 5 animals, but that's good, 5 are enough to start fights, scar the child and yeah: they increase soldier skills (Fighter, Dodger and Armor user). And il ike the lovely decoration work the dogs do....blood red is never out of fashion.
Making the child enter the chamber is actually easier than i believed at first. Just make a burrow and assign all your adult dwarves and childs you do not want to be part of the project. Order a constructed wall inside the chamber to be deconstructed and, because all your adults are burrowed, a child will take the labor...then use the method of your preference to lock him: hatch to an inferior level, Dwarf water slide, Catapult, or as i do: iron bridges.
another hint, make that spot in the chamber food stockpile, or else the roast will rot.
TomTheDwarf, i await your results, good luck.