Securing the future of beef production in Africa — ScienceDaily

A ‘world’s first’ study of indigenous cattle genomes in Africa has revealed vital clues that will help secure the future of cattle production on the continent.

Livestock are an increasingly important resource in Africa as a sustainable source of food, milk, traction and manure. With its human population growing and the resulting economy and wealth expected to expand dramatically, there will also be a huge increase in demand for livestock.

Today, Professor Olivier Hanotte of the University of Nottingham and the International Livestock Research Institute (ILRI) in Ethiopia, together with Professor Heebal Kim of Seoul National University, mapped the genomes of five African cattle breeds and discovered unique genetic adaptations that could inform and improve future breeding programs. The research is published in the journal Genome biology.

The intensification of animal production is a big challenge in Africa, partly because of climatic variations, but also because of infectious and parasitic diseases. Since their introduction to the continent thousands of years ago from their centers of origin in the Near East and northern Indian subcontinent, African cattle breeds have gradually adapted genetically to cope with their environments. varied, from the Sahelian desert to the sub-humid. rainforest and it is these useful adaptations that the team has identified.

Professor Hanotte said: “This paper is important because it is the first time that the African cattle genome has been studied in detail. The results will better inform breeding and crossbreeding programs to improve the productivity and resilience of livestock in sub-Saharan Africa and crucially preserve the genetic diversity of the species. The African continent is currently experiencing major transformations in its agricultural systems and a rapid loss of native livestock. Unfortunately, the opportunity to explore this treasure trove of diversity may not last very long as current random breeding programs mean some of this diversity will be lost.”

For Dr Jaemin Kim, co-lead author of the paper, the sequencing and genome analysis of these African breeds has been a unique journey of discovery: “For the first time, we were able to identify at a precise scale the regions of the genome implicated in the unique adaptation of African cattle.”

There are about 150 breeds of cattle in Africa. The research team therefore chose five distinct breeds that represent the genetic diversity of the species over a wide geographical area. Professor Hanotte said: “We analyzed each animal’s genome and looked for what it did well (eg coping with hot weather, resistance to infectious disease). We then generated a catalog of genetic variants in our five breeds and identified the unique regions of each breed’s genome that give them an advantage.”

The team analyzed DNA samples from 48 animals from five breeds – the N’Dama taurine from West Africa, the Ankole long-horned sanga from Central Africa and three breeds of zebus (Boran, Ogaden and Kenana) from East Africa. Genes have been identified linking feeding behavior to the control of parasitic infection in the N’Dama, horn development and coat color in the Ankole and thermoregulation (heat tolerance) in the three breeds of zebus. Genes associated with tick resistance were identified in all five breeds.

The larger goal of the research team is to catalog all 10,000 breeds of domestic livestock in the world as part of the “10,000 Livestock Genome Project”. Professor Hanotte said: “We want to document the diversity of global livestock before that diversity is gone forever, so that we can compile a catalog of genetic information for future sustainable livestock improvement programs. We estimate it would cost around $70 million — a small investment for such a large global public good.”

An earlier article by Professor Hanotte published in Science documented the fascinating history of livestock in Africa and traced its arrival on the continent from the “fertile crescent” in Turkey and Iraq, and from India.

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Material provided by University of Nottingham. Note: Content may be edited for style and length.

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