Winn Dixie Wild Bird Seed

[BeckyinFl]

Is a lot cheaper than chicken feed and has no preservatives; any reason I can't use this instead of feed?

 

[ChickenCanoe]

Lots of reasons. First and foremost, chickens are omnivores, not exclusively seed eaters.
They can eat bird seed but need much more protein than bird seed provides and preferably from animal sources.
Vegetarian based chicken feed gets around this conundrum by adding lysine, methionine and sometimes other amino acids in synthetic form.
Secondly, chicken nutrition has been studied ad nauseum for over a century and the specific vitamin, mineral, fats and energy needs of chickens are well known. They are provided completely in chicken feed.

The bird seed can work as a scratch grain but still shouldn't be more than 10% of the total diet.