Genetics: Angus joins growing trend towards single-step analytic approach

Beef Central, 08/12/2017


THE Angus breed has joined the early Australian trend-setters in adopting single-step genetic selection.

The December 2017 Angus BreedPlan analysis represents the start of a new era for the genetic evaluation of Australian Angus cattle with the implementation of a new and improved approach for incorporating genomic or DNA information into the calculation of Estimated Breeding Values.

Similar single-step analytical models have recently been implemented into the Australian Brahman and Hereford breeds, and a growing number of other animal breeding genetic evaluations around the world.

The new single-step approach replaces the traditional, multi-step process for incorporating genomic information with a new process that simultaneously utilises genomic, pedigree and performance information. It places appropriate emphasis on all available sources of information, to generate the best possible prediction of an animal’s breeding value.

The implementation of the new approach into the Angus BreedPlan genetic evaluation is a result of collaborative research and development over recent years between the Animal Genetics & Breeding Unit, the Agricultural Business Research Institute, Angus Australia and the New Zealand Angus Association, with funding assistance from Meat & Livestock Australia.

Angus Australia’s breed development & extension manager, Andrew Byrne said the new single-step analytical approach ensured Angus breeders had access to the latest genetic evaluation technology.

“The new approach will ensure the EBVs published for Angus animals provide the best possible prediction of their genetic merit,” Mr Byrne said.

Having the most reliable breeding values available on Angus animals would assist Angus breeders to select cattle that are carrying genetics most aligned with their breeding objective, with more informed selection decisions heightening genetic improvement within Angus breeding programs, he said.

The Angus breed has long led the Australian beef industry with the application of breeding and genetic technologies through BreedPlan, and the application of genomics is no different.

Genomic information has been incorporated into the Angus BreedPlan genetic evaluation since 2011, with genomic profiles now analysed in Angus BreedPlan for more than 30,000 animals.

The new single step analytical model revolutionised the whole approach to incorporating genomics in Angus BreedPlan, said Dr Brad Crook, manager for genetics research and development at ABRI.

“Rather than blending genomic predictions with traditional EBVs, the single step analytical software combines the pedigree, performance and genomic information from the start, one process, with all sources of information being used together,” Dr Crook said.

“This means the genomic information contributes directly to EBVs and accuracies, without requiring external prediction equations, and contributes to all traits in the main multi-trait Angus BreedPlan analysis, not just a sub-set of traits for which prediction equations exist,” he said.

In addition, the influence of genomics extends beyond those animals that were genotyped, with a flow-on effect to relatives of these genotyped animals.

Dr Crook said the single step analytical software also took into account the actual degree of relationship between genotyped animals and their genetic proximity to the animals in the reference population, being the population of Angus animals that have both genotypes and phenotypes for a particular trait.

The end result is the calculation of the EBVs for Angus animals that represent the best estimate of their genetic merit, ultimately arming Angus breeders with tools that will ensure the profitability of Angus genetics continues to increase throughout all segments of the beef supply chain.

The EBVs for all Angus animals have been re-estimated in the December 2017 Angus BreedPlan analysis, using the new analytical model. The changes can be accessed from the Database Search facility on the Angus Australia website.

Angus Australia has also made a technical bulletin available providing more information on the new approach for incorporating genomic information into the calculation of Angus BreedPlan EBVs.

How has your preferred breed performed in 2017?

Coming up: Genetics Central presents its 2017 annual bull sales summaries, listing the sales performance by average price and number of bulls sold for Australia’s statistically significant beef breeds. Seven years of records make it easy to compare the 2017 performance for each breed with earlier years.


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