Tropentag, October 5 - 7, 2004 in Berlin "Rural Poverty Reduction through Research for Development and Transformation"

High Genetic Diversity Indices of two West/central African Cattle Breeds: Hope for More Future Improvement Options?

Justus-Liebig-Universität Giessen, Department of Animal Breeding and Genetics, Germany

Abstract

The Red Bororo and White Fulani are the main cattle genetic resources in the West/Central African region and are the most important in terms of number and economic value. Genetic diversity indices in 108 Red Bororo and 102 White Fulani animals from Cameroon and Nigeria were evaluated using genotypes of 16 microsatellite and seven protein markers. Mean (MNA) and effective (MNE) number of alleles and expected (Hexp) heterozygosity values according to marker type were high. MNA and MNE at microsatellite loci ranged respectively from 5 to 14 and 2.202 to 6.378 and at protein loci from 2 to 6 and 1.566 to 4.626. The range for Hexp was from 0.549 to 0.848 at microsatellite loci and 0.364 to 0.788 at protein loci. These values are higher than observed for highly specialised European breeds and directly opens the way to positive exploitation in improvement breeding. During the last 50 years in Europe and North America, strong selection pressure through intensive breeding programs let to highly specialised breeds and with it lost of genetic diversity. There currently exit no effective selection programs for the zebu breeds of West/Central Africa. Considering that about 90% of the Red Bororo and White Fulani herds are owned and managed by Fulani and Hausa pastoralists/agro-pastorialists, their improvement programs must give consideration to this, and also maintain diversity for future exploitation.

An overall significant (P<0.001) deficit of heterozygotes due to inbreeding within individuals (Fis) was 6.4%. Fit (global deficit of heterozygotes) was low (7%) but highly significant (P<0.001). The two breeds were very lowly but significantly differentiated (Fst = 0.6%, P<0.001). A high level of gene flow (Nem = 5.370) was detected between the breeds. Their history of origin and the high level of genetic exchanges between them could cause the very low level of differentiation. Practical and effective pastoral management practices to curb continued genetic exchanges and to maintain diversity would be to geographically demarcate the different breed groups. Finally, improvement schemes for the breeds must also take into account future unknown traits of economic importance by maintaining within the populations all the currently observed alleles.

Keywords: African cattle, improvement options, genetic diversity, management practices

Contact Address: Georg Erhardt, Justus-Liebig-Universität Giessen, Department of Animal Breeding and Genetics, Ludwigstrasse 21b, 35390 Gießen, Germany, e-mail: georg.erhardtagrar.uni-giessen.de