Genetic improvement in the breed is delivering at the abattoir

Samuel Boon, Signet Breeding Services

For several decades Hampshire Down breeders have measured the performance of lambs on their farms with the aim of enhancing their value at the abattoir.

This hasn’t been their sole focus, as they have also worked to produce fit, fertile and structurally correct sires, but by measuring lamb growth rates and using ultrasound scanning to assess muscling they have continually sought to enhance the carcase attributes of Hampshire Down sired lambs.

The challenge in this approach is that it has always focussed on proxy measures for the traits of economic interest, namely carcase weight, conformation and days to slaughter.

Through the involvement of Hampshire Down breeders in RamCompare, the National Progeny Test, we now have a much better understanding of the genetic relationships that exist between those traits measured in the live animal within our pedigree flocks and those attributes expressed at the abattoir by commercial lambs at the point of slaughter.

In 2025 the National Terminal Sire Evaluation will be enhanced to produce breeding values that are direct predictors of abattoir traits, using the flow of data from both pedigree farms and progeny tests. For the first time producers will be able to confidently select rams on the basis of their EBVs for days to slaughter, carcase weight, conformation and fat class.

What has this evaluation of abattoir data shown?

The latest results derived from AHDB funded research shows exactly what the Hampshire Down breed has achieved through performance recording, with lambs born into recorded flocks now having the genetic potential to finish 10 days faster, with significantly heavier carcases.

AHDB’s research shows that over the last five years improvements in carcase conformation have accompanied these changes in growth rate, whilst levels of finish remain relatively unchanged over the same period.

Genetic trends show that the whole breed is progressing from the performance recording taking place within Signet recorded flocks, as recorded sires of high genetic merit are sold into the unrecorded population.

How can Hampshire Down ram buyers use this data?

When buying Hampshire Down rams, commercial ram buyers should select stock sires with high EBVs for Scan Weight and Muscle Depth if they wish lambs to finish quickly and receive a premium for conformation.

In addition, ram buyers can start using the new breeding values for abattoir traits, such as Days to Slaughter and Carcase Conformation to refine breeding decisions and capitalise on the best genetics the breed has to offer.