Eggs - What is the Difference?

Working with food safety and having an extreme interest in agriculture I have been asked several times about the differences between the quality of farm fresh eggs vs the ones you find at the grocery.  Though this can be a dissertation in itself, I will leave you with a couple points and address a few misconceptions.

Myth:  Farm eggs are better because they are fresher. 

    The truth is that freshness, or rather time between when the egg is laid compared to when it is consumed, is actually a minor consideration when considering which is better.  An egg can keep at room temperature for a much longer time than most people think and longer than the FDA/USDA folks recommend.  If you don’t believe me consider this:  a chicken can lay an egg every 28- 36 hours.   A clutch of eggs can number up to 20 eggs before a setting hen will begin to sit on the nest and begin incubation.  This equilibrates to about a month between when that 1^st egg was laid and when the hen started sitting on it.  Obviously it did not spoil in that month and during that month the hen did not refrigerate that egg.  Conclusion:  Good eggs do not spoil very quickly even at moderate temperatures.

Fact:  In reality egg at the grocery store is probably fresher as large egg production facilities collect eggs, clean them and refrigerate them within minutes to hours of them being laid.  A farm egg could easily sit out for a day or more before being collected.  However, like was said above, freshness is only a minor consideration.

Myth:  There is no difference between farm eggs and commercial eggs in regards to quality, nutritional value and animal welfare. 

Fact:  There are a number of differences.  These differences all relate directly to how the animal is raised and what it is fed.  Common sense dictates that an animal with a more well-rounded diet with access to varied food inputs will be healthier than animals that are confined with a poor (bare minimum) diet.  Commercial establishments balance food inputs compared to egg output and look for the most economical balance with minimal regard for animal husbandry practices.  Often this leads to poor nutrition, antibiotic prophylaxis, and overcrowding.

Besides the obvious fact that chickens raised in their natural habitat is probably better husbandry then raising chicken in extremely crowded wire cages, there are a number of reasons to choose free range farm eggs.  Eggs that are farm raised tend to have higher values of Omega-3 fats, Vitamin E, vitamin D, folate, and a number of antioxidants.  Commercial eggs often fall behind in nutritional value compared to farm eggs.  The proof is in the pudding or in this case the egg.  Outside of expensive nutritional tests, a visual test will quickly show the average person the difference.  Most farm eggs will have darker yolks, appear less watery, have yolks that stand “taller” and have thicker shells.      

Notice the difference?  The egg on the left is from a local farm and the egg on the right is from the local supermarket.  The left egg has a darker yolk, the yolk is more elevated (raised) and appears less watery

DISCLAIMER:  There are other considerations that people should take to heart as well.  Although farm eggs are likely to be healthier, the unregulated diet of the hens could expose them to sources of toxins such as heavy metals, pesticide residues etc.  It is always a good idea to be familiar with the farm from which you buy your eggs.  Also, pathogens from private flocks (as well as commercial) can make their way into the eggs.  Cook your eggs well.

REFERENCES / FURTHER READING

Nutritional value of eggs from SFGATE

GREAT article from Mother Earth News

USDA food safety page for eggs

USDA nutritional values for eggs