Hair Sheep in the US: Historical Perspectives
University of California, Davis
"Hair sheep" is a term that until relatively recently was not familiar to U.S. sheep producers and others in this country working with sheep. Although sheep with little or no wool had been known in parts of Texas since early in the 20th century, they were unknown or little known elsewhere in the country until 1970 or later.
Such sheep originated in the tropics and are the type of sheep best adapted to the tropics, especially the humid regions. Although virtually none of the U.S. is in tropical latitudes, the existence of substantial areas of the country with a warm, humid climate, plus an unfavorable ratio of shearing costs to price of wool in most years, have led to an increasing interest in the U.S. in these animals.
The first recorded introduction of hair sheep to the U.S. was a USDA importation of Barbados Blackbelly animals from the island of Barbados in the early 1900's. These sheep came to Texas, where they were crossed with Rambouillet and Mouflon, with the resulting stock sometimes referred to as the "Barbado" breed. The second importation of hair sheep to the US was of "fewer than 10" Virgin Island White sheep from the island of St. Croix in 1960; they were crossed with U.S. breeds to create the foundation for the Katahdin breed, and no pure descendants were kept.
In 1975, 3 rams and 22 ewes were imported from St. Croix by Utah State University, and rapidly multiplied to become what is known in the U.S. as the St. Croix breed. As indicated, these two breeds both came from Caribbean islands. Hair sheep (including a number of breeds/types not yet imported to the U.S.) are the predominant type of sheep in Caribbean and northern Latin American countries, but all such animals descend from hair sheep that came from West Africa one to two hundred or more years earlier, presumably in connection with the slave trade.
The U.S. Barbados Blackbelly and St. Croix breeds have been evaluated in crossbreeding trials with wool breeds in several locations in the U.S. The results indicate that, compared to wool sheep, hair sheep and, to a lesser extent, hair x wool crossbreds, in general are: smaller at all ages and have lower average daily gains, have carcasses with less subcutaneous fat but a higher % kidney and pelvic fat, have higher fertility of both rams and ewes, are less seasonal and lamb more frequently in accelerated lambing systems, have equal or higher litter size, lamb without assistance, and have lower fecal egg counts for common internal parasites.
More recently, semen and embryos of South African Dorper sheep have been imported via Canada and Australia. Because of their larger size and better carcass conformation than the St. Croix, they have been used in some private flocks to grade up from a St. Croix base to produce white hair populations. Nearly all if not all hair sheep in the U.S. have some inheritance from wool breeds. This has the advantage of broadening the genetic base of U.S. hair sheep populations, which is very narrow in terms of breeds sampled and size of samples within those imported, but usually results in animals that are not completely free of wool.
Some challenges in developing successful hair sheep production systems in the U.S. include increased sampling of hair breeds from other countries, development of efficient means of breeding wool-free animals from hair x wool crosses, utilizing the genetic potential of hair breeds for resistance to internal parasites, and increasing size/growth rates of hair sheep intended for traditional U.S. lamb market channels.