Everyone who has eaten eggs from chickens who run loose in the grass and chickens raised in cages or warehouses knows that eggs from pastured chickens have a far superior color, structure, and taste. One would logically expect the eggs from pastured chickens to also be healthier.
Mother Earth News had eggs tested from 14 flocks in different parts of the U.S.
They found that, as compared with eggs from penned or warehoused hens, the eggs from pastured hens had:
• 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
This is not a huge sample size, and the article does not go into details such as the variance within the results. Nevertheless, they are interesting results, and there are other studies showing similar results. The article points out what one could easily guess just by looking at the thin shells and pale yolks of warehoused "free range" chicken eggs sold in supermarkets. The USDA definition of "free range" includes hens who live in crowded warehouses and never see a blade of grass in their lives. I have a picture of such a place in another entry on this blog: http://huerto-de-altamira.blogspot.com/2009/01/35000-free-range-chickens.html
Given the misleading USDA definition, factory farms can label eggs from warehoused hens as "free range" and gullible people pay twice as much, or more, as they would pay for factory farm eggs laid by caged hens. As pathetic a life as caged hens lead, the lives led by warehoused hens is probably even more terrible.
On a happier note, my hens have a pleasant wooden house where they roost at night, and in the day time they run around eating whatever plants appeal to them, and scratching in the soil for insects. Here are the eggs I gathered from mine over the past week (minus the ones we ate).
The green and pinkish ones are from the Ameracaunas. The brown ones are from the Rhode Island Reds and Dominiques. The eggs themselves are pretty, but it's what's inside that really counts. The yolks are deep orange-yellow, rather than the insipid pale yellow of warehoused or caged hens. You should see how easy it is to separate the yolks from the whites!