Beef, the meat of an adult (over 1 year) bovine, wasn't always as popular as it is today. America has had cattle since the mid-1500s, but most immigrants preferred either pork or chicken. Shortages of those two meats during the Civil War, however, suddenly made beef attractive and very much in demand. Today's beef comes from cows (females that have borne at least one calf), steers (males castrated when very young), heifers (females that have never borne a calf) and bulls under 2 years old. Meat packers can request and pay for their meat to be graded by the U.S. Department of Agriculture (USDA). The grading is based on three factors: conformation (the proportion of meat to bone), finish (proportion of fat to lean) and overall quality. Beginning with the best quality, the eight USDA grades for beef are Prime, Choice, Select, Standard, Commercial, Utility, Cutter and Canner. The meat's grade is stamped within a purple shield (a harmless vegetable dye is used for the ink) at regular intervals on the outside of each carcass. Stock is the strained liquid that is the result of cooking vegetables, meat, or fish and other seasoning ingredients in water. Organic food is produced by farmers who emphasize the use of renewable resources and the conservation of soil and water to enhance environmental quality for future generations. Organic meat, poultry, eggs, and dairy products come from animals that are given no antibiotics or growth hormones. Organic food is produced without using most conventional pesticides; fertilizers made with synthetic ingredients or sewage sludge; bioengineering; or ionizing radiation. Before a product can be labeled "organic," a Government-approved certifier inspects the farm where the food is grown to make sure the farmer is following all the rules necessary to meet USDA organic standards. Companies that handle or process organic food before it gets to your local supermarket or restaurant must be certified.