On the subject of covering the "little spots" like the LH cow in the post by
@crossbreed . You find this pattern the most in LHs. Not so much in pure Corriente. Corrs wil have more of a "paint" pattern. Much like the Herf/Hol
@MurraysMutts has. Or the Herf/Guresney I have. Most Corrs that aren't a shade of brown/tan. or black, or white, will look like those. Corss can have a coat that looks like a red-faced Hereford, or like the red & white Simms had, or a Guernsey, or Holstein. Usually when the little spots get in them, they have had some LH blood infused in them somewhere. None of our Mexican Corrs were "roan", but the ones we had that were, were US cattle. A lot of people would cross the Corrs with LH for faster, bigger bull dogging steers. Booger Barter would use them as "prize steers" in his competitions.
The first cattle the Spaniards brought, were most likely solid colored. As they dispersed, we saw that those along the southern coast....Fla, Ala, Miss, LA, etc... tended to evolve horns that grew narrow and up, rather than wide and long, like the LHs. As these cattle dispersed across the nation, and as pioneers settled across the west, they brought their milk cows with them, including Shorthorn and Ayrshires....both of which display a lot of roan-ing coats. And that is how that color got into the wild Longhorns. Fla Scrubs and Crackers, and Pineywoods cattle.. Corriente, not so much. Not saying there are NO Corrs with the "little spots", just not so prevalent as in LHs.
I have talked about Clay's boss who feeds out 900-1000 1/2 Brangus each year, He has 400 cows of his own, probably 390 of them pure Corr. He will use about 395 average a year in his program. He also provides bulls to several out fits in Florida which have mostly Fla Scrub/Cracker, and buys the calves at 6 mos old. He buys about 600 a year, and often only 500-550 go into his program. He only uses the solid black and polled calves for his deal where he sends them to the Oklahoma feed lot. Sometimes you might see one or two in his feed lots with a white star. We had one LH/Watusi cross, that often produced a black, but scurred calf. Hard to overcome that African Horn gene. And we had a Pineywoods cow, that was black with white roan-ing on her belly and up on her flank a little. A lot of her calves had that too, just not as much as she did. Everything else we had, from 100-120 a year, was polled and black, using the bulls we do, and 90% of the cows being Corr.
. I love RWF mommas. They are pretty. And they can have black calves. 
