I had a pair raise 7 successfully one time, but that's not the usual case. If they hatch more than 4, I always pull the oldest ones as soon as the others hatch to give the little ones a chance. Since the eggs hatch every other day as a rule, by the time the 5th hatches, the oldest is about 10 days old, so not a bad age for hand feeding. I generally pull for hand feeding at 12-13 days anyway, because they adapt easier than older chicks do. Taking the youngest works as well, but the every 2 hours feeding schedule is brutal so I would only do that if the parents are refusing to feed the youngest, which does happen sometimes.