2020 Analysis enhancements

2020 Analysis enhancements

Sheep Genetics evaluations are updated and improved each year which ensures breeders have access to the best tools to improve genetic gain across the sheep industry.

Major updates to these evaluations are implemented once a year (April/May) to minimise disruption.

2020 Analysis enhancements

The following short videos, and associated written summaries explain the 2020 analysis enhancements:

Updated fleece weight means

Have you ever noticed that the ASBV for CFW drops between yearling and adult age stages?

This is because the assumptions around the standard means for fleece weight at each age stage were estimated when there was very little adult fleece weight data in the evaluation.

These fleece weight means will be updated because we have enough data at each age stage to make the means more relevant to the current analysis.

Breeders will see a general shift in CFW, particularly for the post-weaning and adult age stages. The direction of this shift is highlighted in Figure 1. This update will also impact indexes, as CFW has a significant contribution to the Merino and Dohne indexes.

This enhancement causes little re-ranking; only 40 of 695 Merino sires move in and out of the top 10% of sires on the MP+.

Who is impacted?

Merinos and Dohne breeders will see a shift in their CFW ASBVs (particularly P, H and A age stages), however this change results in little re-ranking between animals.

Footrot ASBVs

Footrot susceptibility ASBVs available for New Zealand Merino breeders.

These ASBVs were developed from research funded by NZ Merino, in collaboration with AGBU, University of Sydney and NeXtgen Agri. These breeding values were recorded and tested in New Zealand only, so are now only recommended for New Zealand breeders.

Footrot infection is recorded by accredited scorers on animals run under a footrot challenge. New Zealand Merino breeders can now submit footrot data to Sheep Genetics.

Almost 44,000 animals will get a reportable footrot ASBV, however these are mostly NZ animals. There are currently over 15,000 footrot records and 6,000 genotypes, with two thirds of these coming from NZ Central Progeny Test sites.

Linkage between the NZ flocks recording footrot and Australian flocks is generally low; only around 100 Australian animals will get reportable footrot ASBVs.

If you are interested in recording footrot, please contact Sheep Genetics to discuss possible options.

Who is impacted?

Merino breeders in New Zealand who record footrot.

Linkage and recording in Australia is too low to provide reportable Footrot ASBVs for Australian flocks.

Flock Profile reporting

Sheep Genetics to deliver Flock Profile. Including the addition of Worm Egg Count.

Flock Profile was developed by the SheepCRC so that commercial Merino producers can genetically benchmark themselves against the MERINOSELECT analysis. Flock Profile helps to inform better ram purchasing decisions.

Flock Profile provides producers with an average ASBV for their flock for fleece, growth, carcase and wrinkle traits. Worm Egg Count will be also included on Flock Profile because the reference population is now big enough.

Following the conclusion of the Sheep CRC, MLA will take over the delivery and support of Flock Profile. Tests will still be ordered and purchased through a genomic service provider.

Flock Profile is currently only available for Merinos. For non-Merino breed types the best way for your commercial clients to monitor their genetic progress is to track their ram teams by looking at the average ASBVs of the sire teams that they are using.

Maternal reproduction research breeding values

Maternal RBVs take a step closer to ASBVs.

More animals have been recorded for reproduction traits enabling heritabilites and correlations to be refined.

New reproduction traits for Maternals were released in 2019 Analysis Enhancements as Research Breeding Values (RBVs). Part of developing these new traits includes determining the heritabilities and correlations from reproduction records. As Maternal breeders have submitted more data into the analysis, the genetic parameters have been refined. All reproduction RBV traits had increased records, notably Ewe Rearing Ability which increased by 32% from 201,000 to 266,000 animals.

Who is impacted?

Maternal breeders will continue to receive the reproduction RBVs throughout 2020. The genetic parameters used in the analysis have been updated.

Updated accuracy algorithm

More accurate accuracies. Accuracies for ASBVs are now slightly improved and faster to estimate across all analyses.

Accuracies were getting harder to estimate with increasing numbers of genotypes in the database. The new accuracy algorithm is better because it:

runs twelve times faster and handles the growing number of genotypes
uses multi-trait contributions from genomics
Traits that rely more on genomic information, like carcase traits and visual traits in Merinos will be the most affected, generally with accuracies increasing.

Overall changes to accuracies are minor with only few animals having changes around the accuracy reporting thresholds. This enhancement does not change the ASBVs or Indexes of animals.

Who is impacted?

Most flocks will have little to no changes in accuracies or reported breeding values. Sheep Genetics will contact breeders with flocks that had major changes in accuracies.

Merino Lifetime Productivity data in MERINOSELECT

Some changes in ASBVs mainly for MLP sires and close relatives.

The lifetime data collected from Australian Wool Innovation (AWI) and Australian Merino Sire Evaluation Association’s (AMSEA) Merino Lifetime Productivity (MLP) project will be included in MERINOSELECT on 21 April 2020 analysis run.

This will include the repeat adult measurements on 5,700 daughters from 134 industry sires.

Performance data recorded up to two years of age was already in the MERINOSELECT analysis but from 21 April 2020, the repeat adult records will also be included for:

  • fleece traits;
  • body weight;
  • fat and muscle;
  • worm egg count;
  • visual traits;
  • reproduction records; and
  • genotypes.

For more information read the joint media between MLA and AWI.

Aligning genomic and pedigree relationships

Single step analysis improved. Genomic relationships are being rescaled to pedigree relationships, so they reflect the same base.

ASBVs are estimated using a single step analysis. Single step means that relationships estimated from pedigree and genotypes are used together to estimate breeding values.

ASBVs are reported relative to the base population for each flock. For pedigree relationships, this base population is based on the first animals in the pedigree. For genomic relationships, however, the base population can be further back than the original animals recorded in the pedigree of a flock. Therefore the breeding values may not reported relative to the same base population.

If a flock has a relatively shallow pedigree and has genotyped extensively recently, the genetic trends may not be providing an accurate estimate of a flock’s true genetic progress. The single step analysis now corrects for these different relationships by scaling genomic relationships back to the pedigree relationship.

This enhancement will be applied to both MERINOSELECT and LAMBPLAN analyses, however the impact on MERINOSELECT will be greater because of generally lower historical pedigree recording than LAMBPLAN.

Who is impacted?

MERINOSELECT analysis will be most impacted, due to lower pedigree recording than LAMBPLAN. Sheep Genetics will contact flocks with significant changes to trend.