Page 116 - 2020 NZ Hereford Magazine

Industry Focus

Two years on: Lessons

from the introduction of

Hereford Single-Step Breedplan

WORDS / DIAGRAMS CATRIONA MILLEN, SOUTHERN BEEF TECHNOLOGY SERVICES

IN OCTOBER 2017, the first multi-country Single-Step (e.g. parent verification where using 50K; compulsory SNP
Breedplan analysis was released for the Hereford breed. genotyping for certain classes of animals) are likely to have
Pedigree, performance and genomic information from three contributed to this rapid uptake.
societies – Herefords Australia (HAL), the New Zealand Hereford
Association (NZHA), and the Hereford Cattle Breeders Society GENOMIC DATA AFFECTS BREEDPLAN EBVS
of Namibia (HCBSN) – is combined in a complete multi-trait The introduction of Hereford Single-Step Breedplan has had
Breedplan analysis of birth, growth, fertility, carcass and feed three main effects.
intake traits.
In October 2019, a paper on the implementation of Hereford 1. EBV movement for individual animals
Single-Step Breedplan was presented at the Association for While the inclusion of genomic information did not change
the Advancement of Animal Breeding and Genetics conference the breed average EBVs, the EBVs of individual animals
in Armidale, Australia. The full paper is entitled Two years have changed considerably. Across traits, EBV movement
in: Lessons from the introduction of Hereford Single-Step occurred in both directions, with some EBVs increasing
Breedplan and can be found on the conference website. and others decreasing. This EBV movement was more
A summary of the key findings of the paper are as follows: pronounced in genotyped non-parent animals (e.g. young
animals) than for sires, although EBV movements were
HEREFORD PRODUCERS EMBRACE evident for both groups. This likely reflects the EBV accuracy
GENOTYPING prior to the inclusion of genomic information; young animals,
There has been a 3.8-fold increase in the number of animals with lower EBV accuracy, showed greater EBV movement.
genotyped since Single-Step Breedplan was released, from
3651 animals in the October 2017 analysis to 13,764 animals 2. Increased EBV variance (spread) for most traits
in the March 2019 analysis. The majority of genotypes were This increase in EBV spread is useful for Hereford producers
supplied by Australia, although there has been a steady increase as it improves the identification of animals at the extremes.
in the percentage of NZHA genotypes (from 0.8% in October The genetically superior animals can be selected for
17 to 12.6% in March 2019). However, given linkage between breeding programmes, while the genetically inferior animals
countries, the benefits of Single-Step Breedplan will extend to can be culled from breeding programmes.
members in all three Hereford breed societies regardless of the
origin of the genotypes used. 3. Increased EBV accuracy
There have also been marked changes to the category of This increase is greatest for animals with a low EBV
Hereford animals with genotypes. In the October 2017 analysis, accuracy prior to the inclusion of genomic data; this trend is
animals with genotypes were born between 1961 and 2016 (as consistent across traits (Figure 2). However, the magnitude
a result of the associations building their reference population), of the increase in EBV accuracy varied across traits. For
with 29% born before 2010 and 39% in 2015 or later (Figure 1). 200 Day Weight, the average increase in EBV accuracy
Just 16% of those animals were female. In contrast, the animals for animals with a prior EBV accuracy of ≤20% was 30%;
with genotypes in March 2019 included many younger animals. for Days to Calving (DtC) it was 5.5% (Figure 2). These
Just 12% were born prior to 2010, while 67% were born in differences appear to be largely dependent on the heritability
2015 or later (Figure 1). Females now comprised 29% of those (the percentage of variation in the trait that is explained by
genotyped. genetics) and the size of the reference population (animals
The rapid growth in the size of the reference population with both genotypes and phenotypes) for the individual
suggests Hereford breeders are embracing genotyping trait. Investigation showed more than 85% of animals with
technology. In particular, the growth in both the percentage genotypes had a 200 Day Weight record; less than 5% have
of younger animals genotyped and the percentage of female a DtC record. To increase the boost to EBV accuracy from
animals genotyped indicates Hereford producers have genomics, it remains critical Hereford producers continue to
genotyped not only older sires but also younger animals (e.g. collect performance information for a range of traits.
young bulls and replacement heifers) in their herds. This is to
be expected, as the greatest benefit of genomics will be seen Genomics has given Hereford producers more reliable
in these animals, with increased EBV accuracy at earlier ages. information, in the form of EBVs that can be utilised to make more
In addition, changing requirements for animal registration informed selection decisions. In turn, this should help improve the
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