High Quality Content by WIKIPEDIA articles! In the United States, chickens were raised primarily on family farms until about 1960. Originally, the primary value in poultry keeping was eggs, and meat was considered a byproduct of egg production. Its supply was less than the demand, and poultry was expensive. Except in hot weather, eggs can be shipped and stored without refrigeration for some time before going bad, this was important in the days before widespread refrigeration. Farm flocks tended to... Mehr