It figures that healthy, happy chickens produce the healthiest eggs. Mother Earth News has a great article about how letting chickens free range or have access to grass/pasture in a coop makes their eggs have higher levels of nutrients than conventional eggs. We prefer the local organic feed over Purina because it Purina does not list ANY of their ingredients. I want to know what my chickens are eating, because in the end, I'm eating it as well.
"In the past, we’ve found that eggs from hens raised on pasture, as compared to those commercially raised factory farm eggs, contain:
• 1⁄3 less cholesterol
• 1⁄4 less saturated fat
• 2⁄3 more vitamin A
• 2 times more omega-3 fatty acids
• 3 times more vitamin E
• 7 times more beta carotene
Plus 4-6x more vitamin D"
Read more: http://www.motherearthnews.com/Relish/Pastured-Eggs-Vitamin-D-Content.aspx