Fly strike in sheep: updates on the cost of control

Sheep strike, caused primarily by the blowfly Lucilia sericata, remains an important seasonal problem in the UK, with losses due to animal mortality and reduced growth rates and costs associated with reactive treatment and prophylactic control as well as the time and labour involved in the frequent inspection of flocks and the need to catch and handle struck animals. While prophylactic treatment may represent a substantial cost for each flock, this needs to be balanced against potential losses. Hence, identifying the most appropriate strategies which reduce cost while effectively managing disease incidence, is important. This will allow an informed risk-based and economically rational decision to be taken about treatments – which is essential given the low economic margins of many sheep rearing enterprises. Previous studies have used a simple spreadsheet model to examine the costs of strike management (Lihou & Wall, 2019), but recent changes in farm economics, updated activity profiles of the insecticidal products available and the impacts of a changing climate make reanalysis timely. Here we compare the potential cost of a range of strike management strategies.