MASSEY
NEWS AND VIEWS
UNIVERSITY
RESEARCH UPDATE
Livestock health and climate change: how prepared are we? Emilie Vallee, Senior Lecturer in Veterinary Epidemiology at Massey University, and Masako Wada, Postdoctoral Fellow in Veterinary Epidemiology at the School of Veterinary Science, describe their research into diseases’ sensitivity to climate change – and the implications for New Zealand farms. BACKGROUND We now know that climate change is highly likely unescapable. The National Institute of Water and Atmospheric Research’s (NIWA’s) projections for New Zealand include a temperature increase of 0.8° Celsius by 2040 and 1.6° Celsius by 2110, a change in rainfall patterns and an increase in extreme weather events (Ministry for the Environment, 2017). However, these projections depict considerably varying climate futures depending on the different greenhouse gas emission scenarios based
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on human behaviours, so the current efforts should be continued or intensified. In its 2019 Climate Change and Land report, the Intergovernmental Panel on Climate Change (IPCC) points out the role of intensive and inefficient farming in contributing to greenhouse gas emissions (IPCC, 2019). It is often overlooked that animals as well as farming communities will also be negatively affected by the consequences. The expected direct effects on livestock welfare and health include heat stress
and exposure to extreme weather events, and the indirect effects include changes in the distribution of arthropod vectors, intermediate hosts and pathogens, and an increased incidence of water-borne diseases. We have already seen evidence of this, such as the increase in Leptospira spp. prevalence in lambs after floods (Dorjee et al., 2008). We also know that the risk of ruminants being infected with liver fluke could increase by up to 186% by 2090 (Haydock et al., 2016) and that some regions in the South Island may become more environmentally suitable for Haemaphysalis longicornis, the vector of the Theileria orientalis parasite in New Zealand (Lawrence et al., 2017). Most livestock diseases in New Zealand have some form of seasonality or climate sensitivity, although it is difficult to summarise and prioritise their importance. Our team, with funding from the Ministry for Primary Industries’ (MPI’s) Sustainable Land Management and Climate Change programme, reviewed the climate sensitivity of livestock diseases present and endemic in New Zealand, prioritised them, identified sources of animal health data that could be used for preparedness, and designed some scenarios for the top five diseases of importance. The team comprised (in addition to the authors) Naomi Cogger, Jackie Benschop and Jonathan Marshall from Massey University and Gregor Macara from NIWA. METHODS For this project we worked alongside a stakeholder and technical advisory group (STAG) comprising representatives from MPI, the NZVA, SPCA, Livestock Improvement Corporation, Beef + Lamb New Zealand and DairyNZ. We began by creating a list of 41 diseases endemic in New Zealand livestock based on the research team’s knowledge, Massey’s undergraduate curriculum and the STAG’s input. We then systematically reviewed these diseases’ climate sensitivity with the help of undergraduate veterinary students from Massey University. At a STAG workshop we established a list of criteria to score and rank the
IMAGERY: SUPPLIED
