Yes private labeling of products is a normal business practice. I dont know why that is hard to accept.
Here is some interesting info about FDA approval:
http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm047470.htm
NLS had this to say: "Our premium line of fish food is made in the USA, in an FDA approved state-of-the-art facility. All of the ingredients used in New Life Spectrum premium fish foods are thoroughly analyzed and certified, ensuring only the highest grade of quality and purity in each and every container of our food."
http://nlsfishfood.com/index.php?option=com_content&task=view&id=26&Itemid=59
Why the fuss about FDA approval, are you also questioning NLS for this?