Yes it is, but when a company wants to start commercially supplying a food product, you can either trust the database information about the "Average" food item tested, such as eggs or you can pay to have your product tested to be very specific. For corporations this specific testing is worth the $ as marketing angles that set your product apart from the competition can really take off- Like EB eggs- They won't make the claim if they didn't have some testing behind that statement, but for a home grower just wanting to know how their feed is affecting their end product, it can feel a bit pricey. you might try the local Colleges or Universities - they might have a nutrition department itching for an interesting project- Especially since you are just looking for one or two specific results.
and Welcome To BYC! SuperK has given you some nice links to get started!
