Major first for UK sheep genetics as genomic breeding values launched

Delivered as part of Signet’s National Hill Sheep Evaluation, the new genomic breeding values implement research by Dr Samir Id Lahoucine at SRUC using funding from the Hybu Cig Cymru (HCC)-led Hill Ram Scheme and Farming Connects Welsh Sheep Genetics Programme. 

Collaboration with Innovis and SRUC has widened the impact and potential of this work.

The new approach incorporates genomic information (often collected as part of DNA parentage assignment) into Signet’s breeding values to generate genomic predictors that are more accurate, informative and reliable.

Genomic data will initially be used to enhance the breeding values of seven hill breeds, including the North Country Cheviot (Hill type), Scottish Blackface and Welsh Mountain.

Genomic approaches are particularly useful for maternal breeds when trying to predict the genetic merit of animals early in their life and when assessing traits with a low genetic component (like lamb survival), that are expensive to measure (like methane production) or that take a lifetime to be expressed (like longevity).

Samuel Boon from Signet explains:

“There are five advantages in using genomic information in sheep breeding programmes, it:

• Corrects parentage errors.
• Provides information on major genes, including harmful recessive traits.
• Lifts the accuracy of breeding value predictions.
• Enables early selection decisions to be made on young animals.
• Provides more accurate comparisons between sheep reared in different flocks.

"This final point may be one of the most important for our national sheep breeding program as the degree of genetic linkage that arises between performance recorded flocks tends to be lower than that observed in beef and dairy industries and thus reliable comparisons of genetic merit are harder.”

Expressing the hill index in economic terms

To make the new breeding information easier to interpret by commercial farmers, Signet are changing the way the hill index is expressed. The hill index developed by Janet Roden was generated using economic principles and it will now be expressed in economic terms representing the relative economic merit of a ram’s daughters.

A ram with a hill index of +£8.00 will breed daughters that we predict to be £4.00 more profitable per annum than a ram with a hill index of £0.

As before, indexes can’t be compared between breeds – but do provide an important way to rank animals based on the economic merit of their genetics.

Updated breeding values for the sheep in the 75 hill flocks that actively record with Signet are now available via its website.