14.5.3.2 An example of introgression: Polledness in cattle (2024)

Polledness in cattle has received increasing interest in recent years for welfare reasons. It makes dehorning of young calves unnecessary. Polledness is based on two different dominant alleles that are situated very close together in the cattle genome. In the dominating mainstream dairy breeds polledness was absent. The polled alleles are found in smaller breeds especially in Northern Europe, where they are fixed or segregating. Genomics is used to identify the carriers which can be used for introgression e.g. in the Holstein Friesian breed.