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Recording Birth Weights and Lambing Ease

Recording Birth Weights and Lambing Ease

Laura Eyles, Signet Breeding Services



With lambing round the corner for many terminal sire breeders, now is an important time to highlight the importance of recording both Birth Weights and Lambing Ease.

Traits influencing lambing ease have a genetic component and breeders can record both lambing ease and birth weight data on Grassroots when pedigree registrations are undertaken.

Even for flocks who don’t currently undertake performance recording this data is still important. Your data contributes to the National Terminal Sire Evaluation, which is important for the breed and supports future genetic research.

How does Signet use this information?

Ease of lambing is important; it has a high economic importance, a major impact on lamb survival and ultimately farm profitability. Lambing ease scores are analysed to identity genetic differences in the ability of a sire’s lambs to be born unassisted and from this Signet can produce breeding values to aid ram selection.

The analysis requires variability to exist within the flock to produce EBVs, thus it is important to record data accurately. Where there is little or no variation in the data supplied it will not be included in the evaluation.

How to record Lambing Ease & Birth Weight

Lambing Ease scores relate to each lamb – so two lambs can have different scores. If you are unsure as to whether a lambing event has been assisted, leave the record blank. Blank scores are interpreted as “no score” rather than “no difficulty”. Score as many lambs as possible, including dead lambs.




No assistance


Slight assistance by hand


Severe assistance


Non-surgical veterinary assistance


Veterinary assistance, surgery required / caesarean section

The birth weight of a lamb will influence how easily it is born. Lambs should be weighed within 24 hours of birth. Weights should be measured, not estimated. Breeders should weigh lambs in kilograms, ideally to the nearest 0.1kg).  Breeders weigh lambs in various ways, with many using a clean bucket attached to hanging (luggage) scales.

About the author

Laura Eyles

Laura Eyles

Laura has joined the Signet team as a breeding specialist, she comes from an agricultural background having grown up on a sheep farm in Cornwall, where they keep commercial ewes and run a small flock of pedigree Charollais sheep.

Laura has a strong interest in animal breeding and genetics having studied Animal Science (BSc Hons) at Harper Adams University. During her time at Harper, she spent an industrial placement in Cumbria working for a sheep breeding company and some of our clients may recognise her from this role. Since graduating she has worked for a large cattle breeding company before joining us at Signet to lead on a number of Signet’s sheep breeding projects.