Wikipedia
The Churra (also known as Spanish Churro) is an ancient Iberian breed of sheep from Zamora province in Castile and León. The ewes produce the milk for Zamorana cheese; the meat is prized also.
The Churra (renamed "churro" by American frontiersmen) was first imported to North America in the 16th century and used to feed Spanish armies and settlers. By the 17th Century, churros were popular with the Spanish settlers in the upper Rio Grande Valley. Flocks of churros were also acquired by Navajo through raids and trading, and soon became an important part of their economy and culture.
In the early 1900s, the federal government decided that other breeds would be better for reservation life and a program of out-breeding nearly caused the churro sheep to go extinct. People concerned with quality of wool and the history and culture of the Navajo are making an effort to save the breed.
Spanish traditional wisdom advises not to mix churras and merinas, i.e., not to confuse different concepts.