HISTORY OF AFRICAN CATTLE

With some 180 million head and more than 150 different breeds or populations of taurine Bos taurus, indicine B. indicus and intermediate origins, the African continent is home to a very large reservoir of cattle genetic diversity. Particularly valuable are their adaptations to heat and drought, their tolerance of disease (e.g., trypanosomosis), and their capability to efficiently utilize low quality indigenous forages. However, despite their importance for millions of people across the continent, the origins and subsequent early history of cattle in Africa remain poorly understood and controversial. 


Two hypotheses for the origins of African domesticated cattle are currently being debated. Archaeological and mitochondrial DNA studies suggest that cattle were possibly domesticated within the continent from the African auroch B. primigenius. However, influences from the centers of cattle domestication in the Near East and the Indus Valley are also expected, for example, following the arrival of small ruminants to the African continent. Continent-wide molecular genetics studies using mitochondrial, Y-specific and autosomal DNA markers have allowed us to unravel the origins and history of African cattle. The earliest cattle were of taurine types. 


They were domesticated within the African continent. However, Near East and European genetic influences are also identified in the North West and the North East, as well as in some cattle populations from southern parts of the continent. The initial taurine expansion was likely from a single region of origin, possibly in the eastern part of today’s Sahara. It reached the southern part of the continent following an eastern route rather than a western one. 


The subsequent pattern of zebu B. indicus introgression, which has now influenced the majority of cattle in Africa, with the exception of some West African taurine populations, shows a major entry point through the Horn and the East Coast of Africa and two modes of introgression: a slow and possibly relatively ancient introgression of zebu genetics into western and southern B. taurus populations, and a likely more rapid and more recent dispersal of zebu genes in East Africa and along the Sahelien belt. Our results show that African indigenous cattle and their crossbreeds represent a unique genetic resource for further improvement of livestock productivity for the benefit of the present and future human generations within and outside the African continent.

By Olivier Hanotte- International Livestock Research Institute, P. O. Box 30709, Nairobi, Kenya. Adapted to be posted by Leopoldo Costa