Birds and Biosecurity: contact rates and parasite exchange between livestock and songbirds

Livestock have access to the outdoor environment, which integrates farm animals with soil, vegetation and wildlife that are components of the farm ecosystem. For example, pasture provides cycling of renewable, organic food inputs for livestock and nutrients from manure. These ecosystem services are vital to sustainable organic animal production. However, livestock in the environment also encounter parasites and pathogens found in soil (e.g. Coccidia) and wildlife (e.g. Influenza virus) that affect animal health and potentially contaminate the human food supply (e.g. Campylobacter). Antibiotics and parasiticides that are available for disease control in conventional animal agriculture are tightly restricted in organic production, which puts a premium on preventative measures to lower risks of infection. There have been few comprehensive, systems-level studies of the infectious organisms that livestock encounter in organic production. The lack of tools for disease management impedes the transition to organic animal production. Working on diverse mixed vegetable farms, a subset of which also integrate livestock into their farming systems, we have conducted surveys of wild bird diversity and density. In addition, fecal and blood samples have been collected from poultry and captured birds to determine the frequency of livestock pathogens in the wild bird community. We have found that wild birds have varying levels of contact with livestock, dependent on wild bird species. In addition, we have detected parasites in both poultry and wild birds that indicate the two groups of birds do exchange infectious organisms. These data have been instrumental in grant proposals to acquire funds for further exploration of the impacts of wild birds on infectious disease in animal agriculture.