The Australian Wagyu Association has developed a genomic test to determine the level of Japanese Black (Black Wagyu) content in a DNA sample from a crossbred animal.
The test measures Black Wagyu content in terms of the animal’s relationship to the mainstream Black Wagyu sub-population available in Australia.
While some Australian fullblood animals will return lower CWT values, this needs to be recognised as an indication of their importance as “outliers” within the local gene pool, and the valuable contribution they can make to maintaining genetic diversity and providing future selection flexibility.
Further development work will endeavour to measure better and define these outlier populations, which have already been identified as descendants of specific, original Japanese Black prefectural herds.
Essentially the CWT measures the genomic “distance” between the genotype of a particular animal being tested and the “clouds” or reference sets of genotypes available for other breeds and delivers the estimated breed content level of each breed within that animal.
The CWT software has been developed by the Animal Genetics & Breeding Unit (AGBU) at the University of New England. It uses a reference dataset for each breed type whose genotypes are currently available.
At least 100 individual animal genotypes, representing the genetic variation in the breed, are required to form an accurate representation of a particular breed, so only the major breeds have sufficient genotypes to enable them to be included at this stage.
Each animal in the reference set requires a genotype of sufficient SNP (Single Nucleotide Polymorphism) density to enable accurate breed determination, with the Low-Density GeneSeek Genomic Profiler (GGPLD) of some 34,000 SNPS currently the minimum (previous GGPLD SNP levels were 10K, then 20K and these have also been used).
The breed genotypes have been provided by a range of industry contributors including AWA through its Wagyu Collaborative Genetics Research Project, Meat & Livestock Australia through the various Beef Cooperative Research Centre projects and other breed associations.