What breed of chicken lays the healthiest eggs?
As others have already noted, the breed of chicken has less to do with the healthfulness of the eggs than the diet and management of the chickens that produce the eggs. One of the advantages to raising your own chickens is that you can control the environment and the diet of the chickens, including choosing whether to use medication or organic products to control or prevent disease, etc. Recently, there have been some advances in producing healthier eggs that have been recognized by the American Heart Association as having benefits to the heart. I believe this is a major breakthrough, and you can read about this in the two articles below. Please refer to the article from the University of Manitoba below which discusses some of the feed considerations in the production of the Omega eggs.