Harnessing data for better flock management

Like it or loathe it, electronic identification in the sheep sector has made monitoring lamb growth rates easier than ever, writes Nerys Wright.

Although official aggregated data is unavailable – and much of the research is diet-specific – knowing the daily liveweight gain (DLWG) of your lambs is invaluable when it comes to improving crop performance.

Lamb weight gain can vary significantly based on factors such as age (as feed conversion ratio declines with age), grazing quality, feed availability, parasite burden, and overall flock health.

Additionally, ewe condition and milk production play crucial roles.

If ewes maintain condition from tupping, mobilising body fat during lactation helps with milk production. However, ewes under condition at lambing will struggle to achieve optimum milk yield and may end up thinner by weaning.

Natural peak milk yield occurs 3-4 weeks post-lambing, after which milk production decreases, encouraging lambs to forage and develop their rumen. Keeping ewes well-fed during lactation maximises peak milk yield and benefits lamb performance.

It’s easy to suggest a target, but it’s not one-size-fits-all. Growth rates vary by management group, lamb age, weather, and diseases such as lameness, parasites, and trace element deficiencies.

Generally, we aim for lambs to reach 20 kg at 8 weeks and 30 kg at weaning (12 weeks). This can be adjusted according to past flock performance and individual farm conditions.

Monitoring worms based on daily live-weight gain allows us to treat underperforming lambs. But you need to know how well wormers work on your farm throughout the year. If worming a proportion of the flock, use an effective product.

Nerys Wright is an independent sheep consultant. For more details, call 07891 187643 or visit sheepconsultancy.co.uk.

Blowfly warning for region’s sheep farmers

Sheep farmers are being advised to apply insect growth regulator to flocks amid an increased risk of blowfly strike.

The free Blowfly Watch service, run in partnership with NADIS, uses a combination of factors – including soil temperature and humidity – raised its blowfly strike risk warning last month.

Matt Colston, ruminant technical consultant at Elanco, says producers should consider early preventative action when the service issues risk alerts in your area. Farmers can protect flocks by applying an insect growth regulator, he adds

“Damage happens fast – it can take as little as 36 hours from an egg being laid on a sheep to maggots eating its flesh – so prevention is better than waiting to see a struck lamb before treating the whole flock.”

Mr Colston says the CLiK range of growth protectors provides options for all types of sheep, whatever the management system – with protection ranging from eight to 19 weeks, and meat withdrawal periods ranging from seven to 40 days.

Top tips

Mr Colston’s top tips for applying a preventative treatment include using an appropriate applicator gun with a fan spray nozzle. This should be carefully calibrate it before use, he says.

The correct dose should be applied to a clean fleece, with any dirty animals clipped or dagged before application. The product should be applied in a band about 10cm wide, holding the gun about 45cm from the sheep.

Mr Colston says the efficacy of preventative treatment relies on the product being applied to clean sheep – aided by effective worm control, as well as actions such as dagging and timely shearing.

“Worm management plays a valuable role in preventing strike, because scouring, due to worms, can cause dirty backends and encourage flies. Regular faecal egg counting will help identify worm burdens early and prompt treatment before lambs scour.”