The Dorper was developed in South Africa during the 1930's by crossing Horned Dorsets with Black Headed Persians.  The average weight for mature rams is 110-135 kgs (240-300 lbs) and 70-90 kgs (155-200 lbs) for mature ewes.  Lambs are fast growing early maturing with an excellent carcass and can reach 45 kgs (100 lbs) in 100 days. 
The Dorper is characteristically barrel shaped, with short black or white hair on the head.  A short covering of both wool and hair is found on the body though the underline has very little wool. They normally shed the wool covering in spring, depending on the environment.  The breed is very hardy and resistant to disease and parasites. Tests in North America have shown that this breed works well in any crossbreeding program.