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.