Food securers or invasive aliens? Trends and consequences of non-native livestock introgression in developing countries.

Importation of livestock genetic resources from industrialized countries for introgression of specific traits and other forms of crossbreeding is often indicative of a shift in production systems toward greater intensification and specialization. In developing countries, imported genetic resources are regarded as both a solution to improve the performance of local livestock and as one of the main threats to local populations. Using international databases, censuses and technical reports, we investigate ongoing trends and consequences of these two phenomena in 40 countries from Africa, Asia and Latin America. In these countries, the share of locally adapted breeds within species has decreased by an average of 0.76% per year over the last 20 years. The corresponding increase has been distributed between pure exotic breeds and crossbred animals, with differences across regions. In several countries, increased utilization of exotic cattle breeds and crossbreeding has been accompanied by a trend in increased milk yield per cow. The shift from local genetic resources to crossbred and exotic animals must be considered in the context of challenges such as food security, erosion of agrobiodiversity, interactions with other agricultural production, reduction of poverty and provision of ecosystem services, as well as resilience to and mitigation of climate change.