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First Release of the 2024 Genomic Evaluation

The first evaluation of this year with the 2024 born lambs included, has been published this week. 

The first evaluation can be a milestone for breeders as they get their first glimpse of how their 2024 lamb crop has been ranked. The genomic evaluation will be running every week, so breeders can expect changes while new animals and data are being recorded, along with the genomic information added after genotyping.

There has not been any updates made to the evaluation for 2024. Any move in an animal’s rankings is due to new data being included in its evaluations.

Last year some updates were made to the genetic evaluation model: 

  1. Ewe Mothering ability trait was included in the Replacement index
  2. Accounting for the mating type of the ewe in the Number of Lambs Born and Barreness ebvs
  3. Blackface Mountain strains (based on Genomic Analysis) were grouped as one breed in the genetic evaluations
  4. Breed solutions for Days to Slaughter and Number of Lambs Born (NLB) were improved

Ewe Methane (g CH4/day)

Last year we also launched new breeding values for sheep aimed at reducing methane emissions and supporting the delivery of climate emission reductions. This is a stand-alone trait and represents the difference in methane output of the ewes bred from the animal. This value doesn’t capture differences due to other aspects such as weight and fertility. The higher the value, the more methane the animal will produce. This trait will be expanded on in 2024 and stars will be available. It is not included in the Replacement or Terminal Index.

Relative emphasis on the indexs

This is the current Relative emphasis for each index (table 1).


These changes increased the model’s accuracy by a few points, giving confidence to improve the breed improvement programme.

As always, before any changes to the genetic evaluation model are released, they are presented to the Technical Advisory Group (TAG), which is comprised of two international experts, an Irish expert, and a Sheep Ireland Board member. Only changes this group agrees on are technically correct and brought forward to the Sheep Ireland board for approval. This process increases the robustness and oversight of the genomic evaluation.

Read more about the Euro-Star Indexs & Traits by clicking on it: