Genetic diversity and population structure of Malawi Zebu cattle

The aim of this study was to determine the genetic diversity and population structure of Malawi Zebu cattle using microsatellite DNA markers. Blood samples were collected in 5 administrative districts of Malawi and analysed at the DNA Laboratory, University of Malawi, Chancellor College, Zomba, Malawi. As a comparison base, samples were collected from a group of Brahman cattle performing at a commercial herd in Zomba district. A total of 15 sites were sampled giving a total of 541 random blood samples. The number of alleles per locus ranged from 6 to 15 with the minimum allele length of 98 base pairs (bp) and maximum allele length of 160bp. Malawi Zebu cattle were found to be more polymorphic than Brahman. Most of the Malawi zebu populations were not in Hardy-Weinberg equilibrium and more than 95% of the population-locus combinations were heterozygous. Gene flow among the populations was higher between districts than within districts, 2.04–2.40 migrants per generation between districts versus 0.36–1.27 migrants per generation within districts). The exchange of genetic material is influenced more by socioeconomic factors like trade and payment of dowry than any conscience genetic improvement practice. Three main clusters of Malawi Zebu were identified in the sampled population. With no organized conservation and improvement programmes currently available, there is need to mobilize on-farm genetic conservation and utilisation programmes and improvement strategies for the indigenous genetic resource, Malawi zebu.