More priority given to twins in revised Lleyn index

A reviewed maternal index and four additional traits have been added to Signet Breeding Services’ Lleyn sheep analysis to identify high performing all-rounders that raise twins.

The changes will control single and triplet births, mature ewe size, while continuing to monitor fat and carcass traits to help productivity and profit.

In so doing, the Lleyn maternal index will address two issues being seen in the breed: ewes getting larger and high index tups lacking prolificacy.

See also: Roundworm estimated breeding value developed for Lleyn sheep

Rewarding twins

This is according to Herefordshire farmer Edward Collins, Performance Recorded Lleyn Breeders secretary, who said the new index will reward ewes raising twins, thereby controlling mature ewe size.

“The weightings on the new index penalise singles, triplets and quads and favour twins,” explained Mr Collins.

“Mature size will be controlled naturally as the larger ewe lambs are often single born and the twin/triplet born lambs are usually smaller.

“Lleyns used to be around 60-65kg, but as they have been adopted in lowland situations the size of the sheep has increased. Mine range from 65kg to 75kg now.”

Ailish Ross, specialist breeding adviser at Signet, said: “These changes to the Lleyn breed’s genetic evaluation will enable breeders to select the most profitable maternal lines to continue improving their flock.

“Buyers at ram sales will also be able to choose animals that are more likely to produce offspring that will perform well in commercial systems, helping to push forward productivity and the success of the breed.”

New traits

The review includes four new maternal traits following research funded by AHDB and undertaken by Scotland’s Rural College/EGENES.

Estimated breeding values are now available for:

  • Ewe longevity (years)
  • Age at first lambing (years)
  • Lambing interval (days)
  • Lamb survival (number of lambs)

Index changes

The index review could mean some rams would slip down the breed rankings, said Mr Collins. But he stressed this was to keep the breed commercially focused and functional.

He said: “One high index tup of mine has gone from a top 10% index to top 25% because he is not a twin, he was born a single.”