Sheep is the oldest domesticated meat species. Sheep have been raised by humans beginning about 9,000 years ago in the Middle East. In many countries, lamb (a young sheep) is the major source of protein. Many Americans think of lamb as a springtime food, but it can be enjoyed year round. The following information answers many questions callers have asked the USDA Meat and Poultry Hotline about lamb.
What is the difference between lamb and mutton?
Sheep (Ovine) carcasses are classified as lamb, yearling mutton, or mutton depending on their age as evidenced by their muscles and bones. For the purpose of this fact sheet we will be discussing lamb. The flavor of lamb is milder than mutton. Lamb is produced from younger animals, typically less than a year old, and mutton is produced from older animals. Most lambs are brought to market at about 6 to 8 months old. A lamb weighs about
140 pounds and yields approximately 46 to 49 pounds of edible lean retail lamb cuts, semi-boneless.
If the phrase “Spring Lamb” is on a meat label, it means the lamb was slaughtered between March and October. The term comes from olden
times when lambs born in harsh winter weather would have little chance to survive until the next year. Today with more protected animal husbandry conditions, enjoying “lamb” is not confined to a particular season of the year.
