Transmission of highly pathogenic avian influenza in the nomadic free-grazing duck production system in Viet Nam.

The presence of free-grazing ducks (FGD) has consistently been shown to be associated with highly pathogenic avian influenza virus (HPAIV) H5N1 outbreaks in South-East Asia. However, the lack of knowledge about the transmission pathways limits the effectiveness of control efforts. To address this gap, we developed a probabilistic transmission model of HPAIV H5N1 in the nomadic FGD production system in Viet Nam, assuming different scenarios to address parameter uncertainty.

Uncontrolled admixture and loss of genetic diversity in a local Vietnamese pig breed.

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.

Examples of probable host-pathogen co-adaptation/co-evolution in isolated farmed animal populations in the mountainous regions of North Vietnam.

In Vietnam, for a number of specific geographical and historical reasons, the mountainous areas have preserved an exceptional diversity of wild and domestic animal species of high socioeconomic interest. This endemic genetic diversity fosters a rapid response to environmental change in mostly isolated local communities and, in particular, fosters the constant adaptation of ecosystems common to humans and farmed and wild animal populations and pathogens. During a 2-year study carried out in several mountainous regions of North Vietnam near the Chinese border, we surveyed 1697 breeders in 249 villages and gathered 5815 biological samples among the four main domesticated species of food animals: chickens, cattle, buffaloes, and goats.