The following article is featured in the May/June issue of the Register magazine. Dr. Jackie Atkins and Sally Buxkemper teamed up to provide you with a very informative, well written article on coat color that might answer most of the questions you have. If you do have more questions, click over to the Science Forum, select DNA Testing, and then either Coat Color Dilution in Simmental Cattle or How do I know if my black cow/bull is homozygous black?, whichever topic your question would be best suited for.
Regarding the pictures below, if you click on them it will bring them up to full screen and you can continue to zoom in if needed.
This spring the American Simmental Association started investigating a possible new red coat color variant. Remington Lock N Load, 2503661, and some of his progeny, appear to carry a red coat color gene that is currently not recognized by the coat color test. In other words, the current coat color test is not able to detect the red coat color gene in animals in this lineage. As a result some animals were called homozygous black but have red progeny. The inheritance and functionality of this gene is likely the same as the existing red coat allele. Animals that are heterozygous for this new variant will pass the red allele to progeny 50% of the time. After mating two heterozygous animals, you can expect 25% homozygous black, 50% heterozygous, and 25% homozygous red calves. The only difference in this case is we are unable to detect this red variant in the current coat color test. The ASA is working with Dr. Clare Gill at Texas A&M to find a marker for the new red variant. If a new variant is discovered, this DNA sequence will be included on the commercially available coat color test. If you know of animals that may carry this red coat color variant, please contact Jackie Atkins at firstname.lastname@example.org with information. The more samples sent to Dr. Gill, the faster we can develop a test for the new variant.