Most eggs sold on the east coast are labeled as Grade A, although almost all of them would meet the requirements for the U.S. Department of Agriculture’s AA grade. This is simply a regional preference, just as most eggs sold in the New England states are brown.
Eggs labeled as Grade A in Wal-Mart stores have an approved USDA specification that requires 85% Grade AA in their pack. Others brands such as Egg Lands Best also require a high percentage of Grade AA.
Most eggs sold commercially in North Carolina are less than four days old when they reach the supermarket. People from different regions may also notice a difference in texture, which may be a result in different feed formulations from region to region. Feed formulas are sometimes based on the most economically available ingredients; here in North Carolina, these formulations are primarily corn and wheat.
— Richard Hoyle, poultry programs administrator