Survey to determine the farm-level impact of Schmallenberg virus during the 2023-2024 UK lambing season.

BACKGROUND

This study aimed to assess the impacts of Schmallenberg virus (SBV) on the 2023/2024 UK lambing season.

METHODS

An online survey was distributed to UK sheep farmers between February and May 2024. Responses were compared across SBV-confirmed, suspected and not suspected farms.

RESULTS

Higher impacts on flock welfare, financial performance and farmer emotional wellbeing were reported on SBV-confirmed (n = 44) and SBV-suspected (n = 84) farms compared to not suspected farms (n = 101), and higher dystocia and dystocia-associated ewe deaths were reported on SBV-confirmed farms. Lamb mortality was higher than in previous SBV outbreaks in the UK. An earlier mating season was identified as a risk factor for SBV.

LIMITATIONS

Cross-sectional surveys are prone to recall bias, and the data accuracy depends on the accuracy of farm records. Farmers who experienced negative impacts of SBV may have been more likely to complete the survey. There is also a risk of selection bias due to the study population being an opportunistic rather than a random sample of UK sheep farmers.

CONCLUSION

This study confirms the significant impacts of SBV on the UK sheep industry, which are likely to be ongoing due to the cyclical re-emergence pattern of the virus.