I have read that corn should not be in the first 3 ingredients of ferret food. Why is this? And when the ingredients are listed on the bag for ferret food is there a agency that checks the companies to make sure that the specified ingredients are in ratio with the portion of being listed as the first ingredient being the most of the percentages with the second ingredient lesser and so forth and how often are they checked. Harriett H. H. [Posted in FML issue 3597]