In cattle, polled refers to the absence of horns in an animal that would normally have them. Polledness is a genetic trait that is controlled by one pair of genes, and it is dominant over the horned trait. This means that an animal with one or two copies of the polled gene will not develop horns. In contrast, an animal with two copies of the horned gene will have horns. Polled cattle breeds have been selectively bred to lack horns, and genetic testing can determine if a polled animal has one or two copies of the polled alleles.