Spring is a pivotal time in the sheep calendar. While it brings new grass growth and the arrival of lambs, it also signals the start of another season for management considerations. Each year the weather patterns vary and therefore parasite challenges change. Make sure you think ahead and discuss with your vet to produce a plan for the year.
Why Parasite Risk Changes
Warmer, more variable spring weather can shift traditional parasite patterns, meaning peak risk periods can change from year to year. This makes close monitoring essential rather than relying on fixed treatment timings.
Key Parasite Threats in Spring:
Nematodirus: The Early-Season Danger
Nematodirus remains one of the most significant threats to young lambs in spring. Unlike many other worms, it follows a “lamb crop to lamb crop” cycle, with eggs deposited by last year’s sheep surviving over winter and hatching in large numbers as temperatures rise.
This can result in disease outbreaks particularly in lambs.. Severe infections can present as profuse diarrhoea and can lead to losses if not addressed promptly. A key factor is timing: if lambs are not yet grazing when the mass hatch occurs, they may avoid infection altogether. Monitoring forecast tools and understanding pasture history are therefore critical for decision-making.
Coccidiosis: A Constant On-Farm Challenge
Coccidiosis is present on most farms year-round, but disease risk depends heavily on management and environmental contamination. Adult sheep may carry and shed low levels of infection without showing signs, gradually contaminating pasture and housing. For lambs optimising hygiene and colostrum uptake are key to reducing the risk.Clinical signs can include diarrhoea (sometimes bloody), poor growth, and, in severe cases, death.
Blowfly Strike: A Rapid and Serious Threat
Blowfly strike is another concern as temperatures rise. Preventative action is essential, as damage can occur within 36 hours of eggs being laid.
Risk tends to increase with favourable weather conditions and can coincide with parasite challenges. Early preventative treatments are often more effective than reacting after cases appear.
The Role of Nutrition in Parasite Resistance
Good nutrition is an important, but sometimes overlooked and poorly understood aspect of parasite control. Ensuring ewes have adequate nutrition before and after lambing supports milk production and lamb growth, helping lambs better withstand parasite challenges.
If grass growth is slow, supplementary feeding may be necessary to avoid nutritional stress, which can leave lambs more susceptible to disease.
Practical Control Strategies
1. Manage Grazing Risk
· Avoid grazing young lambs on fields used by lambs the previous year
· Use “clean” or low-risk pastures where possible
· Consider lamb age and grazing exposure when assessing risk
2. Monitor and Time Treatments Carefully
· Utilise forecasting tools to identify high-risk periods
· Target treatments based on risk rather than routine
· Seek veterinary advice to ensure correct product choice and timing
3. Maintain Good Hygiene and Stocking Practices
· Reduce overcrowding in lambing areas
· Keep bedding and feeding areas clean
· Minimise build-up of contamination between groups
This is especially important for controlling coccidiosis, where environmental build-up drives infection pressure.
4. Act Early on Blowfly Prevention
· Think about preventative treatments ahead of peak risk
· Monitor weather conditions closely
Final Thoughts
Parasite control is not a one-size-fits-all approach. With weather patterns and parasite risks, successful management depends on observation, timing, and informed decision-making.
By combining good nutrition, pasture management, and targeted treatments, farmers can reduce losses and support strong lamb performance throughout the grazing season. Ultimately, a proactive strategy – rather than a reactive one – remains the most effective defence against parasite challenges.
Talk to the team at Dugdale Nutrition
Whether you’re looking to support lamb performance through the grazing season or want advice on supplementary feeding during periods of slow grass growth, our team is here to help.
We work with sheep farmers to build practical, farm-specific nutrition programmes, backed by over 175 years of experience in animal feed and grassland management.
Get in touch with Dugdale Nutrition today:
📞 01200 420200
📍 Bellman Mill, Salthill, Clitheroe, Lancashire BB7 1QW
For grass seed advice and reseed planning, our sister company RBC Agri can help you build a sward that support your farm from the ground up.
Contact your DN Specialist or use the contact details above to get in touch.
