DISCOVERING WAGYU’S BEST MARBLING GENETICS. 

The task of discovering the best Wagyu genetics for Marbling and Marbling Fineness has become much easier with EBVs for those revenue driving traits now available on 78,657 animals in Wagyu Australia’s database. This is a dramatic 10 fold overnight increase on the previous 7,893.

With the rapid growth in demand for elite Wagyu beef in Australia and globally, production is expanding rapidly, with major opportunities available for producers and processors. Well described, high performing Wagyu genetics are in high demand.  In response, Australian Wagyu seedstock registrations doubled in 2013 and increased a further 14% in 2014.

The Australian Wagyu Association has used world renowned BREEDPLAN genetic analysis technology since 1992, producing Estimated Breeding Values (EBVs) to describe the economically important traits in Wagyu production, including fertility, maternal, growth and carcase.

Further improvement in the Wagyu BREEDPLAN technology has been undertaken over the past two years through a Wagyu Collaborative Genetics Research Project utilising joint funding from Meat and Livestock Australia. Stage 1 of the project was conducted with the following aims:

  • To collect carcase and genotype data on 2-3000 Wagyu fullblood and crossbred animals slaughtered at commercial abattoirs including data collected using the Japanese Digital Camera
  • To calculate the heritability of the traits measured including the Camera Image Analysis traits and the genetic relationships with Australian industry-standard assessments such as the AUS-MEAT Marbling Score.
  • If the traits are heritable and have economic value, to investigate the calculation of Estimated Breeding Values for those traits and possible new Indexes for the Wagyu breed.
  • To investigate whether genomic data can be used to estimate genomic relationships to provide or augment pedigree data on these animals

Stage 1 Outcomes:

  • Carcase data including carcase weight, Aus-meat marbling score, P8 rump fat depth, and up to 11 Camera Marbling traits was collected on 2215 carcases.
  • The data was analysed by the Animal Genetics and Breeding Unit (AGBU) with heritabilities and genetic correlations calculated.
  • The heritability of key traits was generally high such as carcase weight (0.47), AUS-MEAT Marble Score (0.52), Camera Marbling Percentage (0.35), Camera Fineness Index (0.50) and Camera Eye Muscle Area (0.62).
  • The genetic correlation between these traits is high.
  • All carcase weight, P8 fat and Rib Eye Area Measurements are now incorporated in the standard Wagyu analysis increasing the accuracy of the EBVs for these traits.
  • New EBVs for Marble Score, Camera Marbling Percentage and Camera Fineness Index are now calculated by the Animal Genetics and Breeding Unit in a multi-trait model.
  • Two of these EBVs, Marbling Score and Marbling Fineness are calculated for all animals in the analysis. The EBV for Camera Marbling Percentage (CCMP) is not published but contributes to the Marble Score EBV.  Although independent scientific studies have established that current AUS-MEAT marble score assessment is unable to measure the highest levels of fullblood Wagyu marbling, these CCMP adjustments are the first step to overcoming this difficulty.
  • A new Wagyu Feedlot Terminal Index is calculated and published for animals in the new analysis, utilising the Marble Score and Carcase Weight EBVs.

These new EBVs and Index were first published in March 2015 enabling more accurate identification, selection and use of high performance Wagyu genetics to accelerate genetic gain in the breed. However; until the most recent analysis AGBU only included a subset of Wagyu animals in the carcase analysis, therefore EBVs were not calculated for all animals. In the October 2015 carcase analysis AGBU included all Wagyu animals which resulted in carcase EBVs being calculated for all Wagyu animals.

At the genetics workshop conducted on the 17th of November, the early identification of young animals as the next generation of parents were shown to be a very important factor influencing genetic gain. To facilitate the identification and use of younger animals as parents, the Australian Wagyu Association Board has decided to publish the EBVs of all animals for those traits with an accuracy of 30% or higher.

The following graphs illustrate the distribution of EBVs and accuracies for Marble Score and Marble Fineness from the most recent carcase analysis.

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The number of animals with reportable Marble Score and Marble Fineness EBVs has now increased from 7,893 to 78,657. This is a great result and will assist members to identify animals with superior genetic potential at a younger age so they can be selected as replacements.

An explanation of the Wagyu Breedplan EBVs, Selection Index and Accuracy can be found by CLICKING HERE.

To view the EBVs of an animal, visit www.wagyu.org.au and select “Animal Search” from the drop down menu that appears when you hold your cursor over “Search” at the top left of the page.

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