The Andalusian Black (aka Serrana Black; Raza Negra Andaluza and Negra Andaluza and Negra de las Campiñas and Serrana in Spanish) is an authentic breed.
The Andalusian Black, the Andalusian Grey and the Berrenda Black Pied differ in coat coloring — but all three originate from Castilian cattle (that then evolved in separate isolated areas).
You can also go to:
The Cow Wall® of Spain
My Daily Cow® Spain and read about other Spanish cattle breeds.