Maximising lamb performance: Expert strategies from CAFRE for Northern Ireland flock owners in 2025

Rachel Megarrell, CAFRE Beef and Sheep Adviser

As lambing season unfolds and ewes and lambs settle into grazing, UK flock owners face the critical task of ensuring lambs achieve optimal growth rates for timely finishing and market readiness.

The College of Agriculture, Food and Rural Enterprise (CAFRE) offers expert guidance to help farmers navigate challenges such as parasite control, lameness, and grass management.

Rachel Megarrell, CAFRE Beef and Sheep Adviser, emphasises, “Flock owners should pay particular attention to a number of factors which may impact lamb performance over the coming months.”

This article explores key strategies to maximise lamb potential this season.

Tackling Parasite Burdens: Nematodirus and Coccidiosis

Parasite management is paramount in the early grazing season, with nematodirus and coccidiosis posing significant threats to young lambs.

Nematodirus battus, a particularly resilient parasite, follows a unique lifecycle. Eggs deposited in sheep faeces develop slowly through larval stages (L1 to L3) within the egg, remaining dormant over winter. A period of cold exposure followed by temperatures exceeding 10°C triggers a mass hatch of L3 larvae, which lambs ingest while grazing.

Timing is critical: lambs aged 4–8 weeks are most vulnerable, as they begin consuming significant grass quantities. Older lambs may develop immunity, reducing risk, while a hatch before lambing may result in larvae dying off before grazing begins.

Megarrell advises using the Sustainable Control of Parasites (SCOPS) forecast, accessible at www.scops.org.uk, which predicts nematodirus hatching based on data from 140 UK weather stations.

Farmers can click on their nearest weather station to assess local risk and combine this with field grazing history. Pastures grazed by lambs late in 2024, for instance, may carry a high risk due to egg deposition from the previous season.

Clinical signs of nematodirus include sudden diarrhoea, faecal staining on the tail, loss of body condition, dullness, and dehydration, with lambs often congregating around water sources. Severe cases can lead to rapid death. Treatment typically involves a Group 1 Benzimidazole (BZ) white drench, which remains effective for young lambs.

Accurate dosing is essential to avoid under-dosing, a common issue. Farmers should weigh a sample of lambs, set the dose for the heaviest in the group, and ensure proper administration by placing the drench nozzle over the back of the tongue. Regular calibration of dosing equipment is also critical.

Coccidiosis, often confused with nematodirus, affects lambs aged 3–8 weeks, presenting with black, blood-tinged scour. Preventive measures include maintaining hygiene, avoiding overcrowding, providing clean bedding, and elevating water drinkers to prevent soiling.

Farmers should consult veterinarians for accurate diagnosis and treatment, which may involve oral doses or creep feed additives.

Managing Lameness: A Persistent Challenge

Ewes and lambs batched up and settled at grass.

Lameness remains a significant welfare and economic issue, with footrot alone costing UK agriculture £20–80 million annually, according to the Agriculture and Horticulture Development Board (AHDB). Regular foot inspections are vital, but routine trimming of all feet can cause more harm than good.

Early diagnosis and treatment are key to effective control.

Interdigital dermatitis, or scald, caused by the bacterium Dichelobacter nodosus, is a leading cause of lameness, particularly in wet or mild conditions.

Symptoms include inflammation of the interdigital skin and potential swelling. Scald in lambs reduces grazing or suckling time, stunting growth, while lame ewes produce less milk, further impacting lamb development.

Control measures include maintaining low sward heights, avoiding high stocking densities, and applying lime around troughs. Treating footrot in ewes also reduces scald incidence in lambs, as both are caused by the same bacterium.

For treatment, targeted antibiotic sprays can be effective but labour-intensive. Regular footbathing, ideally during routine handling for vaccinations or shearing, is often more practical. Farmers should ensure clean feet before treatment, using a water-filled footbath before the main solution.

Solutions must be used at manufacturer-recommended concentrations, with sheep standing in the bath for the advised duration. Post-treatment, sheep should stand on a dry, hard surface for up to an hour and be moved to clean pasture ungrazed for at least two weeks.

Optimising Grass Utilisation for Growth

Grass is the most cost-effective feed for lambs, but maximising its potential requires careful management.

Grass growth typically accelerates in May, and farmers should aim to match supply with stock demand. Tools like rising plate meters or sward sticks can help estimate grazing days. If grass is scarce, supplementing lactating ewes with concentrate feed until swards reach 4cm is advisable.

Paddock grazing systems, with rotations every three weeks, can enhance grass utilisation. Lambs should enter paddocks at around 8cm sward height and graze for three days before moving.

Creep grazing, where lambs access the best grass ahead of ewes, can boost performance by 20–30g per head per day, according to Teagasc trials. This system allows lambs to graze while remaining in visual contact with their mothers, reducing stress.

Cost-Effective Flock Management

Efficient management minimises costs and boosts profitability. While grass is economical, its quality must translate into live weight gain.

Dosing, footbathing, and labour are significant expenses, so precision in these tasks is crucial. For instance, accurate dosing based on weight and proper footbath maintenance can prevent wastage and ensure effectiveness.

Flock health underpins success, and prompt veterinary consultation is essential for any concerns. CAFRE’s website (www.cafre.ac.uk) offers further resources, and farmers can contact local Beef and Sheep Advisers for tailored advice.

Conclusion

Maximising lamb performance in 2025 requires a proactive approach to parasite control, lameness management, and grass utilisation. By leveraging tools like the SCOPS forecast, adopting precise dosing and footbathing techniques, and optimising grazing systems, UK flock owners can enhance growth rates, improve welfare, and boost profitability.

As Megarrell notes, attention to these factors is critical to ensuring lambs reach their full potential this season.

For further information, visit www.cafre.ac.uk or www.scops.org.uk.