The SRD breed is found in northeastern Brazil and is a meat breed derived from Crioul with some recent lop-eared blood, chiefly Anglo-Nubian and Bhuj. The name stands for Sem Raca Definida, meaning without defined breed.
References
Mason, I.L. 1996. A World Dictionary of Livestock Breeds, Types and Varieties. Fourth Edition. C.A.B International. 273 pp.