generally considered to be an "unimproved" or "heirloom" breed (one that has survived with little human selection). Such breeds have been left to mate amongst themselves, often for centuries, and therefore retain much of their original wildness and physical characteristics. American breeders have not subjected Jacobs to extensive cross-breeding or selective breeding, other than for fleece characteristics. Like other unimproved breeds, significant variability is present among individuals within a flock. In contrast, the British Jacob has been selected for greater productivity of meat, and therefore tends to be larger, heavier and have a more uniform appearance. As a result, the American Jacob has retained nearly all of the original phenotypic characteristics of its Old World ancestors while its British counterpart has lost many of its unimproved physical characteristics through cross-breeding and selective breeding. The British Jacob has thus diverged from the American Jacob as a result of artificial selection. Jacobs are typically hardy, low-maintenance animals with a naturally high resistance to parasites and hoof problems. Jacobs do not show much flocking behaviour. They can be skittish if not used to people, although with daily handling they will become tame and make good pets. They require shelter from extreme temperatures, but the shelter can be open and simple. They tend to thrive in extremes of heat and cold and have good or excellent foraging capabilities. They can secure adequate nutrition with minimal to no supplementation, even in the presence of suboptimal soil conditions. Due to their low tail dock and generally unimproved anatomy, Jacob ewes are widely reputed to be easy-lambing. Jacobs are seasonal breeders, with ewes generally cycling in the cooler months of the autumn. They will begin to cycle during the first autumn following their birth and most often the ewe's first lamb is a single. Subsequent gestations will typically bear one or two lambs in the spring, and triplets are not unusual. The lambs will exhibit their spotting and horn characteristics at birth, with the horn buds more readily apparent on ram lambs. Lambs may be weaned at two months of age, but many shepherds do not separate lambs and allow the ewe to wean the lamb at about 4 months of age. Jacob ewes are instinctively attentive mothers and are protective of their lambs. They are included in commercial flocks in England because of their ease of lambing and strong mothering instincts. Use Wool and skins Jacobs