Stitches can trap in bacteria. One reason it's not recommended for chickens.Okay that’s good, but I would say if you can you should get it to a vet to stitch it up, you might need to isolate it so the others don’t hurt it more put ointment on it about 1-2 times a day and try to bandage it up so it’ll heal if you can’t get to a vet
Bandages will stick to the wound, & impair healing. It needs to air heal.