And while it is illegal to give poultry hormones in the United States, antibiotic use to promote animal growth, as well as to prevent disease, is nearly universal in intensive farming and ranching of animals.

FORBES: 'All Natural' Turkeys? One Huge Reason to Buy Them

Indeed, the shop prices of beef, pork, poultry and lamb are higher than in 1995, while the prices farmers get at markets are lower (see chart).

ECONOMIST: Farming