Assaf sheep are the result of crossbreeding between Awassi and East Friesian Milk sheep. In 1955, researchers of the Israeli Agricultural Research Organization (A.R.O) started this project aiming to improve the fecundity of the Awassi sheep.
Most dairy sheep breeders in Israel have adopted the Assaf, which is considered not only a top quality dairy sheep and excellent mutton producer, but is also well-adapted to semi-extensive to extensive production systems.