The importance of recording lamb management groups at eight weeks old

The importance of recording lamb management groups at eight weeks old

To ensure accuracy in performance recording data breeders should remember that lambs can be divided into up to nine different management groups when submitting eight-week weights, says Signet breeding consultant Sion Parry.

To ensure accuracy in performance recording data breeders should remember that lambs can be divided into up to nine different management groups when submitting eight-week weights, says Signet breeding consultant Sion Parry.

Any lambs that have been treated significantly differently to the rest of the flock should be treated as a different management group, this can include;

• Groups of animals born a lengthy period apart, such as February and April born groups.

• Groups of animals given additional supplementation to prepare for shows or sales.

• Groups of animals that suffered a growth check due to a disease outbreak, such as orf or coccidiosis. 

Failure to correctly identify different management groups will have a knock-on effect on the genetic analysis of weight records and, therefore, the EBVs produced for these animals. Many examples where indexes change over time can be directly attributed to the influence of unrecorded differences in management.

Although it is important to allocate lambs to different management groups. Breeders should also be wary of over-using management groups. The analysis of the genetic merit of lambs is optimised when the contemporary groups (the defined group in which an animal’s performance within the flock is compared) are as large as possible.

This follows the principle that a good lamb is more likely to stand out in the analysis when compared to 15 or more lambs as opposed to a group of five or less. Therefore, prior to the submission of eight-week weights, the allocation of lambs to different management groups should be carefully considered.