By Kayleigh Devine,
PhD student, Moredun Research Institute
Farmers are under increasing pressure to produce food efficiently while reducing greenhouse gas emissions, improving biodiversity and maintaining animal health. Finding grazing systems that can deliver these goals is a key focus for the industry.
One area receiving particular attention is how the industry can use grazing management for parasite control. Roundworms remain one of the biggest health challenges facing grazing sheep and cattle, reducing growth rates and productivity while costing the UK livestock industry an estimated £260 million every year through treatment costs and production losses. Slower-growing animals stay on farm longer before reaching finishing weight, increasing production costs and the farm’s environmental footprint.
For decades, worm control has relied heavily on anthelmintic drenches (wormers). However, increasing reports of wormer resistance mean these products are becoming less effective on many farms. As a result, researchers are looking at how manipulating grazing management might help reduce roundworm challenge while maintaining performance and preserving the long-term effectiveness of available treatments.
At the Moredun Research Institute, researchers have spent the past three grazing seasons comparing rotational grazing with traditional set stocking. Rotational grazing involves moving livestock through a series of cells, grazing each area intensively before it is rested to allow for recovery. Alongside potential benefits for pasture production and biodiversity, this approach may also influence the numbers of infective roundworm larvae on pasture.
Studies from warmer climates suggested this could reduce parasite challenge due to UV exposure, but Scotland’s cooler, wetter conditions may produce different results. Understanding how these grazing systems perform under Scottish conditions is therefore essential before recommendations and policy decisions can be made.
The project has been monitoring pasture production, lamb growth and parasite burdens under both systems. Preliminary findings suggest rotational grazing produced greater pasture mass than set stocking, improving grass availability. However, no differences were detected in the numbers of infective roundworm larvae present on pasture.
Lambs managed under set stocking achieved, on average, slightly higher liveweight gains, reached finishing weight sooner and had slightly lower faecal egg counts. Overall, there was no difference between the two systems in the number of worming treatments required per animal.
These findings highlight the need to better understand how pasture production, animal performance, and parasite dynamics interact. As the study enters its final year, researchers are continuing to investigate why these differences occur and what they may mean for commercial livestock systems.
While research farms allow detailed measurements to be collected under controlled conditions, they cannot capture the full range of management decisions made on commercial farms. Every farm differs in stocking rate, weather conditions, pasture type and management, all of which influencing outcomes. Understanding what works best in practice is, therefore, essential.
To help answer these questions, researchers from Moredun Research Institute, the University of Glasgow and the James Hutton Institute are inviting all livestock farmers from across the whole of the UK to complete a questionnaire on grazing management and parasite control.
The survey, which takes around 20 minutes to complete, aims to build a clearer picture of the grazing strategies currently being used, how farmers manage roundworms, and their views on different farming systems. Whether you rotationally graze, set stock or use another approach, your experience will provide valuable information to help researchers understand how their findings compare with commercial farming.
Farmers completing the questionnaire can also register for a follow-on study. Five farms will be recruited during 2026, before expanding to around 20 farms in 2027.
Participating farms will receive free monthly faecal egg counts throughout the grazing season, together with optional pre- and post-treatment faecal egg counts for farmers wishing to assess the effectiveness of their worming programme. Fresh grass samples will also be collected, with all results returned directly to participating farmers. These results can also be shared with the farm’s veterinary advisor to help support future parasite control decisions.
By combining detailed research data with farmers’ practical experience, the project aims to improve understanding of how grazing management influences parasite control, pasture production and livestock performance under real farming conditions. The evidence gathered will help inform practical recommendations for sustainable grazing on UK livestock farms.
By taking part, you’ll help ensure future grazing advice reflects both research and farmers’ experiences. Any questions email k.devine.1@research.gla.ac.uk
Share