Best Way to Develop/Maintain a Herd

[Caustic Burno]

Homozygous black Simmental bred to Herefords are all BWF. Homo. black any breed bred to Herefords will come out BWF.
The Hereford white face, bellie, tail are the determining factor if the offspring will carry the Hereford markings.
If the Hereford is a commercial animal and may or may not have other breeds involved, will determine what white markings the offspring has. Hereford's white markings are Homozygous in Purebreds and dominant. (I am not a Hereford breeder, but this is what I have been told).

You can get a solid black out of a registered Hereford cow.
I had to get a geneticist from the AHA to explain it to me.
Here's my best shot the cows dam and sire each had a dominant and recessive gene for the white markings.
The offspring ended up with two recessive white genes that a homo black bull could cover up half the time.
Now that is how it was explained to me
It was also explained it is not a common trait.