Oculocutaneous hypopigmentation (OH) is a cosmetic genetic trait affecting Simmental and Angus populations. Cattle with OH have uniformly light colored irises and a chocolate coat color. OH is a simple recessive trait (like red coat color) meaning an animal must carry two copies of the OH mutation in order to display the phenotype. Animals can carry one copy of the OH mutation and appear normal. The impact of an animal with OH may be similar to traits like coat color and horned/polled. The reported calves with OH have a distinct appearance but were otherwise normal calves.
For anyone interested in testing possible OH carriers, GeneSeek is now offering a stand alone test for OH. The OH test costs $25.00 and can be ordered through the ASA (DNA@simmgene.com or call 406-587-4531).