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Miniature-Cattle.com breeding miniature cattle 10 Things to Understand about Genetic Mutations in Cattle
see also: DNA Tests in Cattle
see also: Testing a Bull before (frozen semen) collection
see also: Biosecurity; quarantine and maintaining a closed herd
see also: Genetics of Coat Color in Cattle
see also: Dwarfism in Miniature Cattle
see also: Breeds of Miniature Cattle in North America

Background for Miniature Cattle breeders: The BD1 and the BD2 tests (the common dwarfism tests done on miniature cattle in North America) are for those two mutations respectively, only. And both of those mutations originated in Dexter cattle. With so much crossbreeding going on in North America by Gradwohl in the 1980s and 1990s, it led to Dexter DNA bringing BD1 into miniature Belted Galloway and miniature Scottish Highland cattle in North America, and also in a few cases in Australia as well.

Whenever you read published scientific reports of research findings, or whenever you speak to any labs that carry out tests for various isolated mutations... they cannot say some of the things I will say in this small article below... because scientifically these are not 100% fact... these are more like, 99.99999999999999% facts... ...there is just a tiny bit of room for one case to come along and strike lightening twice, etc... but this list of "facts" helps clarify how different mutations (genotype) may function to produce the same conditions (the phenotype). This list of "facts" also demonstrates the relationship between breeds and provides highly probable evidence of their history and development.

GENETIC MUTATIONS
10 interesting facts

  1. Genetic diseases in cattle are tissue specific viz; skeletal, central nervous system, blood, skin /hair, muscle or ophthalmic.
  2. Genetic disease is caused by inborn abnormalities, or mutations, in genes or chromosomes.
  3. Genetic mutations are very common, and exist (probably numbering in the 100s) in most all living animals. The possibiliy of how many mutations could occur in any one population over time, is practically infinite.
  4. On the opposite end of the spectrum, is the probability of one exact same mutation happening more than once in the same breed or population of animals, which is close to nil. That possibility would be comparable to finding 2 unrelated people with identical fingerprints.
  5. Generally speaking, if the exact same genetic mutation is found in 2 different animals, they are related, and both trace back to one single animal that the mutation originated in. That is why particular genetic mutations are found in breeds that share history, or in specific breeds, or in certain bloodlines, depending upon how long ago the mutation occurred and has spread.
  6. Many genetic mutations are undesirable. Most of those cause spontaneous abortions or do not survive into breeding aged animals. Some mutations that are surviveable over the generations, are useful. These mutations are essentially how populations survive changes, and evolution occurs.
  7. Some genetic conditions are markers for economically important or desirable traits (as an example, desirable hair for club calves may result from alleles located close on the gene to the PHA mutation, which initially led to its increase among Maine Anjou club calf cattle).
  8. There can be a number of different mutations that result in the same disease (for example, there are several mutations that cause bulldog chondrodysplasia dwarfism in cattle).
  9. Each different mutation requires its own particular DNA test to identify it (even though the condition they cause may be identical).
  10. Genomic technology is ever-evolving. Before making any financial decisions, such as implementing DNA testing in your cattle program or even choosing a breed, check for the latest updates on research, lab-testing, 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. herd bulls) and store them for potential future research.

go home little cow
go home little cow

sources include:
Progressive Cattle
Genetic Defects • www.eBEEF.org • 2014-9
publisher: Vintage Publishers
published online: March 2019
author: Donna Grace