I am getting 5 baby ducks in the mall. In stories guide to raising ducks it says that from 1 day -2 weeks of age they need 20-22% protein then needs to be reduced to 16-18%. I need to figure out how many lbs of the 20% stuff to buy. Or I need to figure out a way to up the protein on the 18%. I do not want to be left with lbs of un usable food because it's is too high in protein. Any suggestions?