By Mary Hearty
Scientists have discovered a new set of detailed genetic markers and information in African cattle that are associated with valuable traits such as heat and drought tolerance, capacity to control inflammation and tick infestation, and resistance to devastating livestock diseases like trypanosomiasis which can make African cattle more productive and resilient.
The findings which emerged from genome sequencing of 172 indigenous cattle, involved a collaborative effort among 10 cohorts across the world.
These cohorts comprised of scientists at the Addis Ababa- and Nairobi-based International Livestock Research Institute (ILRI), Seoul National University (Republic of Korea), Rural Development Agency (RDA, Republic of Korea), University of Khartoum (Sudan), The Centre of Tropical Livestock Genetics and Health (CTLGH, Scotland), Swedish University of Agricultural Sciences (Sweden), and the University of Nottingham (United Kingdom).
“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,” Olivier
Hanotte, Principal Scientist at ILRI, Professor of Genetics at the University of Nottingham and Program Leader at CTLGH, who led the work at ILRI said.
“We’re fortunate that pastoralists are such skilled breeders,” Hanotte said. “They left a valuable roadmap for efforts underway at ILRI and elsewhere to balance livestock productivity in Africa with resilience and sustainability.”
Hanotte and his colleagues discovered what co-author Steve Kemp, Head of ILRI’s LiveGene program and Deputy Director of CTLGH described as an “evolutionary jolt”.
This 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, known as Zebu, with local breeds of cattle known as Taurine.
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 Taurine to endure humid climates where vector-borne diseases like trypanosomiasis are common.
“You can see from studying the genomes of indigenous cattle that breeding for environmental adaptation has been the key to successful livestock production in Africa,” said Kemp. “And that has to be the factored in our future efforts to develop more productive, more sustainable animals. If the goal is pure productivity, you’re doomed to fail.”
It is now important to use the full range of natural genetic endowments that have made African cattle so resilient to sustainably meet Africa’s surging demand for milk and meat, while minimizing negative impacts of increased livestock production.
“Livestock, especially cattle can be controversial, but without them, millions of people in Africa would have been forced to hunt wildlife for protein,” co-author Ally Okeyo Mwai, a principal scientist at ILRI who leads its African Dairy Genetic Gains program noted.
“That would have been devastating for the African environment and its incredible diversity of wildlife.”
For many households in Africa, and especially the poorest, livestock in general and cattle, in particular, continue to be a family’s most valuable asset. They provide a critical source of protein and micronutrients alongside income to pay for things like school fees.
They also provide manure for crops, and some African cattle breeds can survive in conditions that can’t support food crops, offering farmers a potential adaptation strategy for coping with climate change.
“It’s important to understand that livestock breeding has long played a vital role in sustaining the health and wealth of African communities,” said ILRI Director General Jimmy Smith.
“The focus on breeding for resilience that guided past efforts provides a touchstone for future work to chart a sustainable path for livestock production in sub-Saharan Africa.”