Murray Grey breed implements Single-Step BREEDPLAN
The Agricultural Business Research Institute (ABRI) is pleased to announce that Murray Grey breeders around the world are set to benefit with the release of several major enhancements in the April 2025 Murray Grey BREEDPLAN analysis, including the introduction of Single-Step BREEDPLAN and a new Calving Ease model.
The Murray Grey BREEDPLAN analysis combines data from five participating breed societies, namely the Murray Grey Beef Cattle Society (Australia), the New Zealand Murray Grey Beef Cattle Society, the Murray Grey Beef Cattle Society (UK), the Canadian Murray Grey Association and the American Murray Grey Association.
Members of the participating breed societies now have access to an analysis that includes genomic (DNA) information in the calculation of BREEDPLAN EBVs. This achievement has been made possible through collaboration between staff at the Murray Grey breed societies, the Animal Genetics and Breeding Unit (AGBU) and ABRI.
Further information on these enhancements is available below:
1. Introduction of Single-Step BREEDPLAN
Unlike the conventional (non-genomics) Murray Grey BREEDPLAN analysis, which used pedigree and performance information, the Single-Step BREEDPLAN evaluation also utilises genomic (DNA) information to calculate EBVs. In this sense, genomic information is providing an extra source of information for the BREEDPLAN analysis to use.
There are two ways in which DNA information can provide additional information for the Murray Grey Single-Step BREEDPLAN evaluation. Firstly, when a Murray Grey animal is genotyped, the analysis can then take account of each animal’s actual genetic relationship with all other genotyped animals in the population. Secondly, the analysis gains extra information by accounting for how the DNA information relates to the performance records for each trait in the analysis.
There are several advantage of Single-Step BREEDPLAN that will be applicable for Murray Grey breeders. If animals are genotyped early in life, and their DNA information included in the Single-Step BREEDPLAN analysis, then this can “boost” their EBV accuracy. Having higher levels of EBV accuracy earlier in life means that Murray Grey breeders can make more informed selection decisions earlier in an animal’s life. In turn, this may assist to drive rates of genetic gain both in the individual herd and for the breed as a whole.
In addition, for Murray Grey breeders with smaller herds and/or undertaking ET programs, EBV accuracy levels are often limited by small contemporary group sizes even when pedigree and performance records are available. If calves are genotyped, however, they can accumulate additional information – and EBV accuracy – via their relationship to the wider genotyped and performance recorded population.
Murray Grey breeders should note that the use of genomic information as an additional data source to calculate EBVs does not diminish from the use of performance data in Murray Grey BREEDPLAN. Indeed, a reference population (animals with both performance data and genomic information) is critical to the ongoing success of Single-Step BREEDPLAN, and Murray Grey breeders are strongly encouraged to continue to collect performance data for all traits that are of importance to their and/or their clients breeding objectives.
2. Implementation of a new Calving Ease model
A new model has been implemented for the calculation of Calving Ease EBVs for Murray Grey BREEDPLAN. This has included a number of improvements:
Updated software which will improve the efficiency of the calving ease analysis.
The implementation of a Single-Step Calving Ease analysis. This means that, for the first time in Murray Grey BREEDPLAN, genomic (DNA) information is being used alongside pedigree and performance information (birth difficulty, birth weights and gestation length) to calculate Calving Ease EBVs. This is particularly beneficial for Murray Grey breeders who have low incidences of assisted calvings for their herds, as genomic information provides an additional source of information for the Calving Ease analysis to utilise.
The formation of contemporary groups for Calving Ease has been re-defined to bring it closer in line with the formation of contemporary groups for birth weight. Specifically, contemporary group formation for calving ease now includes the use of breeder-defined management groups submitted for birth weights, and the previous seasonal age slicing will be replaced with a 45-day age slice. As a result, there have been changes to which animals are analysed for Calving Ease – some animals will no longer be analysed, while others will be analysed for the first time.
The ability to fit genetic group solutions in the Calving Ease analysis. Genetic group solutions ensure that when new animals enter the Murray Grey BREEDPLAN analysis, their EBVs do not start at zero, but are instead assigned a starting value that reflects the average performance of other ‘similar’ animals (i.e. of the same age, country of origin and/or breed).
As a result of these enhancements, Murray Grey breeders can expect to see changes to EBVs, associated EBV accuracies and selection indexes. In particular, genotyped animals that had a low EBV accuracy prior to the introduction of Single-Step will likely see the biggest increases in EBV accuracy following release of Single-Step BREEDPLAN, although the magnitude of EBV accuracy increases will vary by trait.