The large animals from which most marketed meats come belong to the animal family of mammals, whose young are milk-fed. The cow's milk has become an important human food. Besides these animals others are used for food, which are smaller : some domesticated, others wild; some of land, others of air. The egg from which some of these spring also becomes human food. It contains what forms the animal and furnishes its food until it is capable of living on food supplied by nature, though provided through the care of the parent.

Chicken is the most generally used of these smaller animals. It furnishes protein food that is delicate and digestible. It is relatively free from fat. As chickens grow old they grow fat and tough, necks long and flesh purplish. The characteristics desirable in chickens used for food are:

Breast plump with breast-bone pliable (not broken); flesh evenly compact (neither hard nor flabby); skin moist, smooth, clear (yellow or white); pin feathers show youth; hairs, age; legs short, thick; feet yellow, soft.

Broilers are young and tender. Fowl requires boiling to be palatable.

Capons are larger than chickens, of finer flavor, and tender in texture.

Turkey is similar to chicken but with more fat. Fat is even further increased in ducks and geese. Pigeons when wild and old are tough and the flesh very dry. Squab (tame, young pigeon) is very palatable. Quail and partridge are similar as foods. Rabbits and venison are also wild, dark, edible meats.

The flesh of all such animals is dry, with less red blood, but with valuable salts and usually less fat. The flavor is distinctive. The dark meat is richest in nutrients; the white requires thorough cooking. The breast is the tenderest part. "Legs of walkers" and "wings of fliers" are the most exercised, so toughest. Storage of such meats for long, changes muscle fibers and connective tissue; also solubility of nutrients.