Homestead Cattle Directory

12 fascinating facts & features of DNA

Homestead & Miniature Cattle Directory printable article

Subject: Facts about DNA mutations that genetics labs may not tell you
Source: Homestead & Miniature Cattle Directory -
Author: Donna Grace Vickery,


Geneticists will probably not be able to say some of the things I say in this short article ... because the following list of "facts" or features of DNA could theoretically be disproven--even if not realistically. In some cases, history, registries, breeding programs, profits and even livelihoods, were built on not understanding some of these DNA features, before we knew much about them--and many of us still do not hear much about some of these "facts". This article is intended to set a foundation understanding about how DNA mutations work, and what they can tell us. This information illustrates how mutations over decades and centuries provide proof of the relationship between breeds and in some cases have provided reasonable doubt or proof of an animal's identity, or of a population or breed's origins, history or development.

  1. Genetic diseases in cattle are tissue specific viz; skeletal, central nervous system, blood, skin /hair, muscle or ophthalmic.

  2. Genetic disorders and diseases are caused by inherited mutatations; which are damaged genes or chromosomes.

  3. In 2016, there were 130 Mendelian traits with known causal mutations in 117 cattle genes. We find more every year.

  4. Genetic mutations do not all cause what we term disorders or disease (for example polled mutations).

  5. Genetic mutations are very common* and we believe multiple mutations probably exist in most or all living animals. The possibiliy of how many mutations may occur in any population over time, is practically infinite. Perhaps that is comparable to how many different places lightening can strike over time. It is said that lightening strikes earth about 8 million times per day.

  6. On the opposite end of the spectrum, is the probability of an exact same mutation happening more than once in the same breed or population of animals over time; which is practically nil. The possibility of that occuring would be considerably lower than the chance of lightening striking twice in the same spot. It might be more comparable to finding 2 unrelated people accused of a crime with identical fingerprints. If I really wanted to put it in perspective, I'd say the likelihood of the same exact mutation happening more than once in the same breed or population of animals over time would be the same chance as me winning the lottery.

  7. Iceland scientists found 40 mutations of the coronavirusFor all reasonable intents & purposes, if the exact same genetic mutation is found in 2 different animals of the same species, they are related. It is reasonable to assume, and to understand that 2 animals with the same exact mutation will both trace back to one single ancestor that the mutation occurred in, and was passed down from. That is why particular genetic mutations are found in breeds that share history, or only in specific breeds, or only in certain bloodlines, depending upon how long ago the mutation occurred and how far it has spread. It may have occured (or discovered) a year ago, or it may have occured somewhere in bovine history before domestication occured. This is how the development of breeds of animals can be documented. Mutations in the DNA of a virus is an example of tracing the spread of Cov19: Iceland scientists found 40 mutations of the coronavirus, report says...

  8. Many recessive genetic mutations are undesirable. Most of them are believed to probably (when inherited as homozygous) result in spontaneous abortions, or do not survive into breeding age animals. Undesirable mutations that are dominant or semi-dominant do not get passed down for long in a breed if the trait is something that mankind or nature culls for. Some mutations are surviveable over generations, or even benign. Occasionally a few are beneficial (to nature or mankind). Mutations, genetic drift, natural selection and migration, are some of the basic mechanisms of evolution, and help populations survive environmental changes, as well as develop breeds under selection pressure.

  9. Some genetic conditions are markers (closely linked) for economically important or desirable traits. Those are the quickest to be spread into the population. For example, desirable hair for club calves may result from alleles located close on the gene to the PHA disease mutation, which initially led to the increase of PHA among Maine Anjou club calf cattle.

  10. There can be a number of different mutations that result in the same identical disease. For example, there are several different mutations that cause the same bulldog chondrodysplasia form of dwarfism in cattle. There are at least 9 known mutations that result in myostatin (double muscling).

  11. Each different mutation requires its own specific DNA test to identify it (even if the disease or condition they cause is identical).

  12. Genomic technology is ever-evolving. Before making any financial decisions, such as choosing a breed, or implementing a DNA testing program in your cattle herd, or signing up for all the DNA tests recommended by your registry, inform yourself. Know your livestock's pedigrees. Know what breeds and what bloodlines are in your animals' pedigrees. Check for the latest research news, lab tests, products and news. If you are not currently testing it may be prudent to collect DNA samples (e.g. tail hair) on important animals in your herd (e.g. A.I. sires, herd bulls, donor cows, or your best replacement lines of cows) and store them for potential future research.


* Dr. Kent Weigel, Professor & Chair, Dep't of Dairy Science, U of WI, Madison; Aug, 2011: "today we recognize that ...inherited conditions are not rare anomalies that occur once in a decade in a handful of genetically unfit animals. ...scientists now believe that it is likely that every individual carries several genes that, if expressed in homozygous form, would lead to a severely impaired or lethal phenotype"


publisher: Vintage Press
owner: Bucking V Outfit, LLC., Maricopa County, Arizona
published online: 01-20-2020
author: by Donna Grace Vickery (

Additional Reading:

DNA TESTS: Homestead & Miniature Cattle Directory of Heritable Diseases
What is the difference between "fullblood" and "purebred"?
BREEDS of Homestead & Miniature Cattle
What to KNOW ABOUT BREEDS of Homestead & Miniature Cattle
What to know about Breed REGISTRIES
How to Calculate Ancestor Blood Percentage ~ a tutorial using your registered animal's pedigree


AgriGenomics Mansfield, Illinois
Biogenetic Services, Brookings, South Dakota
Neogen, GeneSeek®, Igenity, SeekSire, Neogen Genomics®, Lansing Michigan
Genetic Visions, Middleton, Wisconsin
MMI Genomics, Davis, California
Pfizer Animal Genetics, Harahan, Louisiana
Reprotec, Tucson, Arizona
UC Davis Veterinary Genetics Lab (VGL), Davis, California
Zoetis Genetics (formerly Pfizer Animal Health), Kalamazoo, Michigan
The American Grey Steppe Cattle Association,
Veterinary Medicine (Eleventh Edition), 2017
Dr. Tony Knight, CSU) (2010)
Genetic Defects • • 2014-9
From Big to Small to Big to Small: A 3-part Pictorial History of Cattle Type Changes Over the Years, by Harlan Ritchie
and too many more to list...


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CAVEAT EMPTOR & takes sole responsibility for sharing of public content and such content is presented for entertainment, educational and commentary purposes only and should not be construed as professional advice from any licensed practitioner. Homestead Cattle Directory occasionally re-posts information from internet public domain areas. The intention is to network, help new cattle owners, and to create a win:win situation with increased traffic to all related sites - not to overstep any bounds. If you want something of yours posted here to be updated, changed or removed, contact Donna Grace.

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author: Donna Grace

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