I have read today, yet again, that a historian believes that the original Spanish cattle that developed into the criollo had De Lidia, or fighting bull genes.  I thought Rouse had put this idea to rest years ago, apparently not.

There are many reasons why it’s just not possible:

1. (See below), breeding records were and are kept for the fighting bulls. That means they would have been kept isolated, so that the bull whose genetic heritage was the chosen one, would be the only one with access to the chosen female.  This means enclosures, not free range pasturage, as virtually all cattle were kept in New Spain (and Alta California.)
2. You are thinking, well gosh, the bull would have been allowed to run around with the ordinary cows, huh? Probably not: no one would want the trouble of bringing him back in by force.
3. Behavior issues: cattle may get cranky but they are not bred to be aggressive, as are the De Lidia fighting bull. You don’t want their genes in your regular stock.
4. Behavior issues, this time human: the owner would have been so proud of owning such valuable stock, that it would have been kept specially.
5. Rouse describes conformation, which is the way an animal looks. Even a non-specialist like me can tell the difference in breed of the De Lidia and the foundation stock of criollo.
6. Scarcity: Rouse tells this story:

“The bullfight was an institution, and progenitors of the De Lidia were selected for aggressiveness.  They would have differed widely in this trait from the old red cattle of Spain, the progenitors of the Retinto.  The fighting animals have heavy forequarters, a narrow rump, and are well cut up in the flank, and in conformation bear no resemblance to the Retinto, which lacks the heavy shoulders,  has a fairly well-rounded rump, and a level middle.  There is a marked difference in horn shape on  the two breeds, particular on the female.  The De Lidia cow has forward thrust horns, with a moderate upturn towards the ends.  The Retinto has much larger horns, widespread and with a distinct upturn.  The color of the Retinto is invariably red or dun or brown, a narrow color pattern, and always solid over the body.  The De Lidia, which has an older written record than any breed of cattle, is known to have been quite varied in color—black, gray, red, various combinations of these colors, and even brindle.  There was certainly a wide divergence in color, as well as other characteristics, between the Retinto and the fighting stock as far back  as there is any evidence.

“There is a record of ‘12 pairs of bulls and cows…..the oldest fighting bull stock in Mexico’ being taken to New Spain [Mexico] in 1552.  This was evidently a very special cattle shipment, arriving as it did four decades after the indies had received its base foundation stock from which the Western hemisphere was populated.  By 1552 the cattle population in New Spain must have reached at least a few hundred thousand— Coronado had entered what is now United States territory twelve years earlier with 500 head.  It is obvious that 24 head of De Lidia cattle, or even several shipments of this size,  all of which would have been carefully segregated from other cattle, could not have a significant impact on the national herd of New Spain.  (Rouse, John E. Criollo: Spanish Cattle in the Americas: University of Oklahoma Press, 1977. p. 20-21.)

So, to review  Rouse: the three cattle breeds from Spain that gave us the criollo were the Berrenda, the Retinto, and the Andalusian black.  No De Lidia.