Impacts of Non-native Species on Livestock

Abstract

Livestock systems have both benefited from and been harmed by the deliberate and unintended introduction of non-native species. The introduction of non-native pests and pathogens into livestock populations has resulted in severe economic, welfare, and public health consequences. These impacts include: competition for resources; livestock mortality and disease; costly eradication programmes; ongoing surveillance to ensure border and post-border biosecurity; and the burden of zoonotic pathogens on human health. In common with other systems, the impact of non-native invasions is determined by the ability of the pest or pathogen to enter the system (incursion), multiply and spread (expansion), and become established and endemic (persistence). The determinants of incursion, expansion, and persistence depend on the pest or pathogen and the livestock system invaded and include climate change, habitat encroachment, the effectiveness of border and post-border biosecurity, and the onset of acquired immunity in the host population. Examples of non-native invaders discussed in this chapter include vertebrate pests (e.g., mammals competing for resources), invertebrate pests (e.g., ectoparasites and vectors for microbial pathogens), and pathogens (e.g., viruses and bacteria). Advances in genome sequencing, and the development and application of models that combine epidemiology and evolution, offer new insights into invasion dynamics and new approaches to reducing the impacts of pests and pathogens on livestock populations.