I'm a day late to hunt for eggs for Easter, but the proto-avian is always in season. Eggs are used to bind together dishes of all sort from savory to sweet, and make a pretty good meal by themselves.
The age old question about eggs as been if they are good for you. Washington nutritionist Katherine Tallmadge takes up the issue in the Washington Post. The good news - eggs aren't necessarily bad for you. The bad news - eggs the way Americans like them - "alongside foods high in saturated fat, such as bacon, sausage and buttered toast," aren't exactly celery as far as healthy eating goes. One other interesting factoid from the article - the Japanese are the biggest egg eaters in the world - averaging 328 of the ovoids every year.
I found a Poultry Fact Sheet from the University of California, Davis that describes some of the ways egg producers are trying to make their products more attractive to consumers. Many people are increasingly concerned about not only egg nutrition, but with the BSE scare, consumers are becoming interested in how all their food is produced.
Regular eggs are laid by chickens in cages inside factory farms. Many of these chickens have their beaks clipped to keep them from attacking their neighbors. The industry claims this is not a big deal- akin to clipping a dog's claws - but this is one of the hot buttons for anti-cruelty and animal rights activists. Generally, these chickens do not have access to the outside. A picture of a particularly crowded site with other problems can be found here. Caution - the pictures from the site that picture comes from are not pleasant in the least.
Eggs from caged chickens account for the majority of domestic egg production and generally have the lowest price. Many of the types below can go for two or three times the price of standard factory farmed eggs.
Cage-Free eggs are laid by chickens that are not confined. They may or may not have more space than their caged counterparts, and they may or may not have access to an outside pen. Pictures from a cage-free farm can be seen here.
Organic eggs are eggs from chickens who, according to the American Egg Board were "fed rations having ingredients that were grown without pesticides, fungicides, herbicides or commercial fertilizers. No commercial laying hen rations ever contain hormones." Nothing is implied about the conditions the chickens are raised in by the "organic" label.
Free-Range Eggs are those produced by chickens that have access to the outdoors. Weather often prevents the hens from accessing the outside however, and some indoor ground nest operations are mistakenly referred to as free-range. Free-range as a label makes no promise about the feed of the hens or organic nature of the eggs.
Producers are supplementing the nutrition in eggs with Vitamin E or Omega 3. The supplementing is done by adding foods rich in Omega 3 or Vitamin E to the hens' diets. The excess is included in the egg, and passed on to the human consumer. Flax is usally added for Omega 3 egg production, and Vitamin E is added directly to the feed to increase Vitamin E output.
Some consumers are more concerned with avoiding salmonella, which has made a comeback in the egg industry after being nearly eliminated during the 1970's. Previously salmonella contamination was due to external dirt and fecal matter. New sanitation procedures for cleaning eggs took care of that source, but in the late 1980's-early 1990's salmonella started to infect the ovaries of chickens directly, leading to the current outbreak.
Although salmonella contamination in eggs is still a low risk, a salmonella infection can be devastating for very young, very old, or immunocompromised individuals. Cooking eggs to the temperature needed to eliminate any chance of infection (as the Center for Disease Control recommends) will turn your eggs into something closer to silly putty than over easy. If you are concerned or are cooking for a high risk individual, the egg industry has come up with Pasteurized eggs.
Pasteurized eggs are briefly exposed to high temperatures long enough to kill any salmonella in the egg without cooking the egg. Really that should read "without cooking the egg that much". Pasteurized eggs have slightly cloudy whites, and must be beaten a bit longer than regular eggs to make peaks or meringue. They taste just about the same.
Finally, there are "vegetarian eggs". There are no standards for calling your eggs vegetarian eggs, but the one provider I've seen promises they are cage-free, vegetarian-fed, non-factory farmed, Omega-3 enhanced, with brown shells.
The brown shell, by the way, implies nothing about the birds being free-range or organic. The eggs don't taste different or special in any way. They just happen to come from a different breed of chicken than the ones that produce white eggs.