The Livestock Conservancy, formerly known as the American Livestock Breeds Conservancy (ALBC) and prior to that, the American Minor Breeds Conservancy, is a nonprofit organization focused on preserving and promoting rare breeds, also known as "heritage breeds" of livestock. Founded in 1977, through the efforts of livestock breed enthusiasts concerned about the disappearance of many of the US's heritage livestock breeds, The Livestock Conservancy was the pioneer livestock preservation organization in the United States, and remains a leading organization in that field. It has initiated programs that have saved multiple breeds from extinction, and works closely with similar organizations in other countries, including Rare Breeds Canada. With 3,000 members, a staff of eleven and a 19-member board of directors, the organization has an operating budget of over a million dollars.

Sheep or domestic sheep are a domesticated, ruminant mammal typically kept as livestock. Although the term sheep can apply to other species in the genus Ovis, in everyday usage it almost always refers to domesticated sheep. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. Numbering a little over one billion, domestic sheep are also the most numerous species of sheep. An adult female is referred to as a ewe, an intact male as a ram, occasionally a tup, a castrated male as a wether, and a young sheep as a lamb.