The key, in my experience, is using a MHP and ditching the heat lamp all together.  I like the cobb 500 strain, they stay active longer, till about 5-6 weeks.  if they get into a normal sleep cycle, they will self restrict to eating only during the day and can be left with feed 24/7 without leg problems.  the MHP vastly simplifies and balances the whole thing.  I transition to grower formula by day 10.