4 digital issues) Global Rate

How does this impact the Al Khamsa Arabian horse?

Arabian horse breeders, especially those interested in preservation of Al Khamsa horses, want to maintain rare alleles and heterozygosity in these unique groups, both in the Middle East and abroad. The remarkable genetic diversity found in the cradle countries suggests these geographically defined populations may contain valuable archives of ancient ancestry. As described in the paper, “The application of modern breeding techniques, such as artificial insemination, is producing an international pedigree of modern Arabian horses marked by genetic homogenization, and in some cases, severe inbreeding. ... This emphasizes the critical need for more detailed studies of genomic diversity in native Arabian horses in order to enable conservation efforts and manage inbreeding in at-risk subgroups.”

As such, this makes understanding the breed’s genetic diversity and the relationships among Arabian horse subgroups an important subject for breeders.

From a slightly different vantage point — most wild species are fixed for the traits that define how that species looks, but overall genetic variation is vital for survival of the species. This is a lesson that carries over to Arabian horse breeding. While homogeneity brings more predictability and consistency in phenotype, it also increases the likelihood of expression of deleterious recessive traits. So, breeders need to seek a balance in selection for desired phenotype, while maintaining healthy variation in other genes.

Genomic studies are bringing about new ways of looking at not only the DNA history of the Arabian horse, but also other breeds. While some of the results may be unexpected, DNA is not the entire story. DNA can help in connecting the past to the present, but the charismatic desert-Arabian horse should first and foremost be appreciated through the lens of the environment that shaped its development and the culture of its original custodian.

Good science leads to more questions and as our understanding of the background of the Arabian horse expands, further questions will arise. For breeders, the information gained from these genomic studies can be used to assist in guiding decisions regarding their breeding programs and the preservation of rare bloodlines. For the breed, the value of these genomic tools is their use by breeders to assist in making decisions that will maintain the quality and health of the Arabian horse.

Acknowledgements:

Special thank you to Dr. Samantha Brooks, Dr. Doug Antczak, Scott Benjamin and Jeanne Craver

References: 1. Cosgrove, EJ, et al.: Genome Diversity and the Origin of the Arabian Horse. Sci Rep. 2020 Jun 16;10(1):9702. doi: 10.1038/s41598-020-66232-1. https:// pubmed.ncbi.nlm.nih.gov/32546689/ 2. Olsen, S. & Culbertson, C.: A gift from the desert: the art, history, and culture of the Arabian horse. (Kentucky Horse Park, 2010). 3. Bowling, A.T.: Genetics of the Horse. in Evans, J. W. [ed.] Horse Breeding and Management. 1992, Elsevier, New York, pp. 207–236. 4. Mackintosh-Smith, T.: Arabs: A 3,000-Year History of Peoples, Tribes and Empires. 2020, Yale University Press. 5. Lambert, CA & Tishkoff, SA.: Genetic structure in African populations: implications for human demographic history. Cold Spring Harb Symp Quant Biol. 2009;74:395-402. doi: 10.1101/sqb.2009.74.053. 6. Kim, et al.: Khoisan hunter-gatherers have been the largest population throughout most of modern-human demographic history. Nat Comm. 2014 Dec 4;5:5692. doi: 10.1038/ncomms6692. 7. Al Khamsa Arabians III. Ed. by Al Khamsa, Inc. 2008 Edition, Al Khamsa, Inc. 8. Ghanim, Y. The Arabian Horse Manifesto – A Draft for Discussion. February 27, 2021. Daughters of the Wind Blog. http://daughterofthewind.org/ thearabian-horse-manifesto-a-draft-for-discussion/

Library of Congress, Matson Collection