User:SJRick/NCSU 402

NCSU 402
NCSU 402 was the name given to the first true Polled Dorset sheep. NCSU 402 was the product of two Dorset sheep and was born polled, without horns, due to a genetic mutation. The Polled Dorset is often confused with the Australian Poll Dorset which was not the result of a genetic mutation, but a result of the introduction of Corriedale and Ryland blood into the Dorset breeding program. Polled Dorsets are ideal for commercial settings because they do not have horns that can get caught in fencing or cause damage when they butt (1)

Background
The Polled Dorset breed was developed at the North Carolina State University Small Ruminant Unit in the early 1950s. In 1949, four hornless lambs were sired from a horned Dorset on an NC State farm. Over the next five years, as part of their normal breeding program, those four ewes and the other ewes on the farm were bred to the horned Dorset. Eventually, a ewe gave birth to twin rams. NCSU 401 was a regular horned Dorset, but his brother, NCSU 402, was hornless. Thus, the Polled Dorset was born. Livestock scientists, the late Dr. Lemuel Goode and the late Sam Buchanan, are credited with identifying and developing the hornless sheep. The offspring of NCSU 402 were bought by other breeders and within twenty years, seventy percent of all registered Dorsets were polled (2)

Conformation
Polled Dorsets are a medium sheep that are prolific, heavy milkers, long lived and produce hardy lambs with moderate growth and maturity that yield heavy muscled carcasses (4) Their fleece is very white, strong, close, free from dark fiber and have wool extending down the legs. When shorn, their fleece averages between five and nine pounds in the ewes with a yield between fifty and seventy percent (3) The staple length ranges from 2.5 to 4 inches with a numeric count of 46's-58's. The fiber diameter will range from 33.0 to 27.0 microns. At maturity, ewes weigh between 150 and 200 pounds, with some weighing more at show condition. Rams at maturity weigh from 225 to 275 pounds. Dorsets are noted for their aseasonal breeding characteristics and are commonly used in crossbreeding to produce females for out-of-season breeding (4) They are one of the few breeds that have this characteristic (3) Multiple births are common and they work well in commercial situations both in the ewe flock and from a terminal sire aspect (3)

More info about conformation
Since the breed first became commercial, it has spread into Canada and become a major contributor to the commercial lamb industry. The breed adapts well to confinement and is readily used in accelerated crossbreeding programs. Polled dorsets do well under grass-based and feedlot conditions and on small holdings with intensive management because they are able to survive so well in confinement (5)

The Dorset's most remarkable trait is its ability to breed out of season, a quality not seen in most wooled breeds; properly managed Dorset ewes produce three lamb crops in just two years. Polled Dorsets are the most popular white-faced breed in North America, while the much less-common Dorset Horn remains in the Watch category ("Fewer than 2,500 annual registrations in the United States and estimated global population less than 10,000") of the American Rare Breeds Conservancy's Conservation Priority Watchlist (6)

Polled vs Horned
The success of the polled variety of Dorset sheep has almost completely obscured the horned variety, consequently the Dorset Horns are experiencing swift decline in registrations, making them a conservation interest. Horned dorsets are non-seasonal breeders but multiple births are not common with that breed. Polled dorsets commonly produce multiple births which makes them more of an asset to breeders (7)