Liverfluke are a familiar feature to producers of upland sheep and beef cattle. These parasites are particularly common with warm, wet weather – the type of weather that may increase with climate change.
By: Dr Shailesh Shrestha – Agricultural Policy Analyst, SRUC
The expectation is, therefore, that incidence of liverfluke will increase as the climate changes. Liverfluke infestation impacts negatively on animal health, and has economic consequences due to reduced productivity. Shailesh Shrestha and colleagues at Scotland’s Rural College (SRUC) have undertaken an analysis of the economic impact that this expected increase in liverfluke incidence could have on Scottish livestock farms.
Using a farm-level economic model, based on Farm Business Survey data from 160 farms, they modelled the impact of liverfluke on farm profit and further modelled what might be the impact due to projected increase of liverfluke damage with climate change. The modelling also took into account reduced productivity due to heat stress as well as increased input costs due to climate change.
The modelling suggested a 6% reduction in productivity for an average beef farm, due to liverfluke damage. This loss increased six-fold when the expected impact of climate change on liverfluke was taken into account. Of course, not all farms are average, and there was wide variation of impact among individual farms.
Unfortunately, the farms that already have a lower profitability were shown to suffer the most. This difference in effect was not so great for the levels of liverfluke infestation experienced now; the impact for the top 25% profitable farms were modelled as having a 4% reduction in profitability due to liverfluke, with the bottom quarter a 7% reduction in profitability. However, when the additional impact of climate change was taken into account, the top 25% of beef farms were projected to have a 5% drop in profitability, whereas the bottom 25% were expected to suffer a staggering 95% drop in profitability. The combined effect of climate change and disease on already struggling farms was devastating in this model.
These results are from modelling data, which means many assumptions have been made. Reality may be different – these data are not predictions, but rather an exploration of potential impacts. As things stand, however, the threat of increasing liverfluke damage, as a result of climate change, could be an existential threat to many farms, requiring some advance thinking on how this threat can be mitigated.
© 2018. ResULTS