Jason said:
Sure is funny how some jump to the registered parent as the culprit when the generic unknown pedigree of the other parent is the far more likely cause.
Solid black Simm cross bull will throw lots of mixed colors. He is solid black, but his genes are not.
Horn genes are random, usually the polled factor will be dominant, but not 100% of the time. Black is usually dominant but not always.
Well, first you have to understand how genes work. They are either Recessive or Dominant. Recessive genes REQUIRE that there be 2 copies for the trait to be expressed. In the case of Dominant genes if there is 1 copy the trait WILL be expressed. Each parent can only pass on ONE gene for any one trait.
So in the case of Solid/Spotted, Solid is Dominant. 1 copy of solid will give you a solid colored animal. Spotted is Recessive, You need 2 copies of the spotted gene to get a spotted animal. Which I believe is what the calf is displaying.
In the case of the whiteface markings or blaze face markings, both are incompletely dominant. Which means that they will be expressed to a greater degree if the animal has 2 copies of the gene or to a lesser degree if the animal has 1 copy of the gene. This is how the Hereford type markings work. If you have 2 copies you will have more white (in the case of a pure hereford) if you have 1 copy you will have less white (in the case of a baldy). There are other genes at work that detirmine whether the animal gets a brockle face (which is also dominant) and also restricting genes that detirmine exactly how much white an animal has on it, using hereford again, this could cause an animal to have a lineback, or to have no feather neck.
So, if you have a solid colored animal, it is possible that the animal carries the spotting gene (same idea as the red gene), but to get a spotted calf out of 2 solid colored animals BOTH parents HAVE to carry the spotted gene. The blaze face or white face gene cannot be there if the animal is solid colored because they are dominant and would be expressed if they were there.
To top this all off, it is possible that a genetic mutation could have happened, but it is very unlikely, as we had 2 cows (mother/daughter) that when bred to this bull (that we know carries the spotting gene) had calves with white marks on their faces. The odds of both having mutations is pretty slim.
As for the horn gene, unless you are running brahman influenced animals, it is RECESSIVE, not dominant, and NOT random. You have to have
2 copies of the horn gene to get horns. Black is always dominant. Regardless of weather the animal has 1 or 2 copies of the black gene, it will be black. Red is recessive, you MUST have 2 copies of red to get a red colored animal. 1 copy of black, and one of red = BLACK.
So I don't think that was the problem. I figure that either someone didn't put in a registered bull, or that there was something hiding in the woodpile there.