Announcing release of Research NZGE Terminal Evaluation

Wednesday 29th November 2023

We are pleased to announce that a new Research NZGE Terminal Evaluation has been released as part of ongoing efforts to enhance genetic evaluations for terminal sires. It provides breeders of terminal sires access to genomically-enhanced breeding values and indexes, and the option to use this new evaluation to select replacement sire candidates.

Its development has stemmed from the need for improved terminal sire genetics, incorporating traits for meat quality. Our research shows that a separate evaluation, which only uses terminal breed genotypes, provides more accurate breeding values than a combined evaluation of terminal and maternal breed genotypes together.

To distinguish between the two evaluations, the current New Zealand Genetic Evaluation (NZGE) will be referred to as the NZGE Maternal Evaluation, and will continue to use Romney, Coopworth, Perendale and Texel (and composites of these breeds) genotypes. The recently released second evaluation will be referred to as the Research NZGE Terminal Evaluation, specifically using genotypes from terminal breeds.

For a more detailed understanding, you can read the technical note on the SIL website, but a list of important information has been summarised below.

Key points:

The Research NZGE Terminal Evaluation has been released under research status, which means some adjustments may still occur before it is finalised.
It will run weekly, and in parallel with the current NZGE Maternal Evaluation. Its results will be released slightly later due to being processed after the NZGE Maternal run.
The same pedigree and trait data is used in both the Terminal and Maternal evaluations.
It uses qualifying terminal breed genotypes (Texel, Suffolk, Poll Dorset, etc.), differentiating from the current NZGE Maternal Evaluation, which includes Texel, Romney, Perendale, Coopworth, and their composites.
The genomic enhancement of BVs will change according to which NZGE the values are reported from.
Values from the Research NZGE Terminal Evaluation trend slightly lower on average than the current NZGE Maternal Evaluation. A percentile band table will be generated for the new Research NZGE Terminal Evaluation to aid with understanding.

Which evaluation to use:

For selecting terminal sires, we recommend using the Research NZGE Terminal Evaluation, given its accuracy in this domain. For choices related to maternal breeds, the NZGE Maternal Evaluation remains the best choice.

Terminal sire breeders have the option to use the Research NZGE Terminal Evaluation results for selling rams. However, given that ram sale season is underway, breeders may prefer to continue using the NZGE Maternal Evaluation results, particularly if their terminal flock isn't undergoing genotyping or not related to genotyped flocks.

The Genotyping Decision Tree on the SIL website provides more detail on which NZGE evaluation to report from.

Your feedback for improvement:

Validation work has been done as well as extensive testing, but we are very interested in feedback from breeders and bureaus. Your insights from using the new evaluation during its research phase are incredibly valuable as we continue to refine and improve the evaluation.

Should you have any question or require further information, feel free to contact us at nprove@blnzgenetics.com, or phone 0800 745 435.