I've also heard the the suggestion that polled animals carry less bone and smaller rumps than their horned counterparts. I don't know if this is true or not. Although given the opportunity to choose between two otherwise identical animals, one polled and the other horned, I would pick the polled animal simply for the convenience of not having to dehorn the calves. Many of my commercial bull buyers also purchase bulls using this method of decision.
I have also heard that polledness is a dominant trait, there are no "hidden" recessive polled genes in horned animals. A horned animal out of one or even two polled parents does not carry the polled gene.
This is not to say that horned animals are not desirable.
You can use the following to help when determining the probability of polledness in cattle. Letters are used in clinical genetics to represent alleles or different forms of a particular gene. This is a single gene trait, so each animal has two alleles - one from each parent. Since polled is dominant it gets the big P and since horns is recessive, it gets the little p.
pp: This animal has horns. An animal must have two genes for horns to have horns.
Pp: This animal would be polled, and carry a recessive gene for horns.
PP: This animal is polled, and does not carry the gene for horns.
Horned(pp) X Horned(pp) =All horned(pp) offspring.
Polled(Pp) X Horned(pp) = 1/2 polled(Pp), 1/2 horned(pp) offspring.
Polled(Pp) X Polled(Pp) = 1/4 polled(PP), 1/2 polled(Pp), 1/4 horned(pp) offspring You will not be able to tell the PP and Pp animals apart, as they are both polled.
Homozygous polled(PP) X Horned(pp) = All polled(Pp) offspring.
Homozygous polled(PP) X Homozygous Polled(PP) = All homozygous polled(PP) offspring.
This is my understanding of Polled vs. Horned genetics. Please do your own research to verify the validity.
Hope this helps.