African indigenous cattle have traits that enable them to survive blistering heat, drought and diseases such as trypanosomiasis, giving hope of breeding a new, superior generation that could boost productivity, a study has found.
Researchers say that interventions such as selection of cattle breeds that can address challenges such as absence of vaccine and increasing drug resistance are urgently needed to boost livestock production in Sub-Saharan Africa.
The study, published last month in Nature Genetics, involved the analyses of the complete set of genes called genomes of indigenous cattle in Africa. It produces the evidence that indigenous pastoralist herders began breeding the Asian Zebu cattle with local breeds of Taurine and this offered traits that would allow cattle to survive in hot, dry climates typical in the Horn of Africa, a region made up of Djibouti, Eritrea, Ethiopia and Somalia.
But the new cattle that emerged retained the Taurines’ capacity for enduring humid climates where vector-borne diseases such as trypanosomiasis are common.
“Our present-day breeding strategy is not different from the past one. One thousand years ago, it allowed us to colonize new habitats. Today, it will enable [us] to respond to market demands for livestock product and to impact the livelihood of millions of smallholders,” says Olivier Hanotte, a co-author of the study and a principal scientist at Kenya-based International Livestock Research Institute.
The findings resulted from a collaborative effort to analyse the genomes of 172 indigenous cattle.
Hanotte, a professor of genetics at the University of Nottingham in the United Kingdom, says that insights gained from this study can be used to breed a new generation of African cattle that holds some of the qualities of European and American livestock that produce more milk and meat per animal but with the rich mosaic of traits that make African cattle more resilient and sustainable.
“If cattle pastoralism was so successful on the eastern part of the African continent, it was because of [an] ancient crossbreeding event between African Taurine and Asian Zebu, a fact that they we have now dated to around 1,000 years ago,” says Hanotte. “Fortunately, we do not have to wait 1,000 years now to get the final product. We have genetic marker-based selection tools and strategies, which allow us to achieve in a few generations what would have otherwise taken several hundred years of human selection.”
Researchers identified two heat shock protein genes and a water-reabsorption-related gene. in African and Asian Zebu or humped cattle. They also found immune-related genes that might be related to the resistance of humped cattle to ticks and tick-borne diseases such as East Coast fever, and might confer some tolerance to viral infections including Rift Valley fever and foot-and-mouth disease.
“These findings are far-reaching in today’s context of improving livestock productivity to respond to the needs of the growing human populations, with further crossbreeding of indigenous African cattle with exotic cattle recommended as one of the pathways for the continent’s food security,” the study says.
Andrew Chota, a postdoctoral scientist at the Nelson Mandela African Institution of Science and Technology, tells SciDev.Net that the discovery is fundamental to future endeavours in using genetic information to improve our livestock.
（March 2, 2021. From “SciDevNTe”)
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Post time: Mar-02-2021