Ecology and Evolution 2012; 2(5): 962–975
Uncontrolled admixture and loss of genetic diversity in a local Vietnamese pig breed
Article first published online: 10 APR 2012
© 2011 The Authors. MicrobiologyOpen published by Blackwell Publishing Ltd.
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Ecology and Evolution
Volume 2, Issue 5, pages 962–975, May 2012
How to Cite
Berthouly-Salazar, C., Thévenon, S., Van, T. N., Nguyen, B. T., Pham, L. D., Chi, C. V. and Maillard, J.-C. (2012), Uncontrolled admixture and loss of genetic diversity in a local Vietnamese pig breed. Ecology and Evolution, 2: 962–975. doi: 10.1002/ece3.229
- Issue published online: 10 MAY 2012
- Article first published online: 10 APR 2012
- Received: 10 January 2012; Accepted: 18 January 2012
The expansion of intensive livestock production systems in developing countries has increased the introduction of highly productive exotic breeds facilitating indiscriminate crossbreeding with local breeds. In this study, we set out to investigate the genetic status of the Vietnamese Black H’mong pig breed by evaluating (1) genetic diversity and (2) introgression from exotic breeds. Two exotic breeds, namely Landrace and Yorkshire used for crossbreeding, and the H’mong pig population from Ha Giang (HG) province were investigated using microsatellite markers. Within the province, three phenotypes were observed: a White, a Spotted and a Black phenotype. Genetic differentiation between phenotypes was low (0.5–6.1%). The White phenotypes showed intermediate admixture values between exotic breeds and the Black HG population (0.53), indicating a crossbreed status. Management practices were used to predict the rate of private diversity loss due to exotic gene introgressions. After 60 generations, 100% of Black private alleles will be lost. This loss is accelerated if the admixture rate is increased but can be slowed down if the mortality rate (e.g., recruitment rate) is decreased. Our study showed that a large number of markers are needed for accurately identifying hybrid classes for closely related populations. While our estimate of admixture still seems underestimated, genetic erosion can occur very fast even through indiscriminate crossbreeding.