Lambs, which are usually defined as sheep that are less than a year old, are utilized by humans for their meat, as well as their skins. Indeed, both of these items are generally considered to have better quality, and correspondingly command higher prices, when they come from younger individuals. For instance, the skin of fetal sheep, referred to as broadtail lamb, is generally more valuable than Persian lamb, which is derived from newborns. Similarly, the flesh of sheep only 6 to 10 weeks old, which is known as baby lamb, is generally more delicate and expensive than spring lamb, or the meat of individuals 5 to 6 months of age.