Cost assessment of the movement restriction policy in France during the 2006 bluetongue virus episode (BTV-8)

International audienceThis study aims at evaluating the costs of the movement restriction policy (MRP) during the 2006 BTV-8 epidemic in France for the producers of 6-9 month old Charolais beef weaned calves (BWC), an important sector that was severely affected by the restrictions imposed. This study estimates the change in the number of BWC sold that was due to the movement restrictions, and evaluates the economic effect of the MRP. The change in BWC sold by producers located inside the restriction zone (RZ) was analyzed for 2006 by using a multivariate matching approach to control for any internal validity threat. The economic evaluation of the MRP was based on several scenarios that describe farms' capacity constraints, feeding prices, and the animal's selling price. Results show that the average farmer experienced a 21% decrease in animals sold due to the MRP. The economic evaluation of the MRP shows a potential gain during the movement standstill period in the case of no capacity constraint faced by the farm and food self-sufficiency. This gain remains limited and close to zero in case of a low selling price and when animals are held until they no longer fit the BWC market so that they cannot be sold as an intermediate product. Capacity constraints represent a tremendous challenge to farmers facing movement restrictions and the fattening profit becomes negative under such conditions. The timing and length of the movement standstill period significantly affect the profitability of the strategy employed by the farmer: for a 5.5 month-long standstill period with 3.5 months of cold weather, farmers with capacity constraints have stronger incentives to leave their animals outside during the whole period and face higher mortality and morbidity rates than paying for a boarding facility for the cold months. This is not necessarily true for a shorter standstill period. Strategies are also sensitive to the feed costs and to the food self-sufficiency of the farm. Altogether, the present work shows the farmer's vulnerability to animal movement restrictions and quantifies the costs of the standstill. These results should assist decision-makers who seek to calculate adequate subsidies/aid or to efficiently allocate resources to prevent future outbreaks