Genome study will be used to breed more productive and resilient African cattle
Scientists have discovered a set of detailed genetic markers in African cattle that are associated with valuable traits such as heat and drought-tolerance, the capacity to control inflammation and tick infestations, and resistance to trypanosomiasis.
The findings, published in Nature Genetics, emerged from a collaborative effort to sequence the genomes of 172 indigenous cattle by scientists from the University of Nottingham, Addis Ababa and Nairobi-based International Livestock Research Institute (ILRI), Korea’s Seoul National University and Rural Development Agency (RDA), University of Khartoum (Sudan), The Center of Tropical Livestock Genetics and Health (CTLGH), and University of Uppsala (Sweden).
The scientists wanted to learn how, after spending thousands of years confined to a shifting patchwork of sub-regions in Africa, cattle rapidly evolved during the last millennia with traits that allowed them to thrive across the continent.
“We believe these insights can be used to breed a new generation of African cattle that have some of the qualities of European and American livestock, which produce more milk and meat per animal, but with the rich mosaic of traits that make African cattle more resilient and sustainable,” said Olivier Hanotte, Principal Scientist ILRI and Professor of Genetics at the University of Nottingham, who led the work at ILRI.
Professor Hanotte and his colleagues retraced the genetic journey that has made African cattle so adaptable. They discovered what co-author Steve Kemp, Leader of ILRI’s LiveGene program, described as an “evolutionary jolt” that occurred 750 to 1050 years ago: the arrival of Asian cattle breeds in East Africa carrying genetic traits that would make cattle production possible in diverse and demanding African environments.
The genome sequencing work yielded evidence that indigenous pastoralist herders began breeding the Asian cattle (zebu) with local taurine breeds. In particular, the zebu offered traits that would allow cattle to survive in hot, dry climates typical in the Horn of Africa. But by crossing the two, the new animals that emerged also retained the capacity of the taurines to endure humid climates where vector-borne diseases like trypanosomiasis are common.
Article: Kim, K., Kwon, T., Dessie, T., Yoo, D., Mwai, O. A., Jang, J., Sung, S., Lee, S., Salim, B., Jung, J., Jeong, H., Tarekegn, G. M., Tijjani, A., Lim, D., Cho, S., Oh, S. J., Lee, H. K., Kim, J., Jeong, C., Kemp, S., Hanotte, O., Kim, H. (2020). The mosaic genome of indigenous African cattle as a unique genetic resource for African pastoralism. Nature Genetics, 52(10), 1099-1110, doi: 10.1038/s41588-020-0694-2
[SOURCE: University of Nottingham]