My local feed store is very urbanized and doesn't carry much for chickens. They only have Purina Sunfresh starter/grower medicated. I know that is a decent feed but from everything I have read on here the chicks do best starting out on 20%+ protein for the first few weeks and the Purina Sunfresh is only 18% protein, since it is also a grower feed. What can I do to up their protein intake for the first few weeks to give them the best possible start? Should I add some cooked yolk to their food?