Aberdeen-Angus Cattle Society Implement Single-Step BREEDPLAN

Feb 2024

The Aberdeen-Angus Cattle Society have become the next breed society in the UK to incorporate genomic (DNA) information into their BREEDPLAN genetic evaluation, using a method known as Single-Step. This major upgrade was implemented in the February 2024 Aberdeen-Angus BREEDPLAN evaluation.

Dr. Brad Crook, BREEDPLAN Manager Genetics Research & Development, says that members of the Aberdeen-Angus Cattle Society have invested considerably in the collection of high density SNP genotypes for registered cattle in recent years. “The implementation of Single-Step BREEDPLAN for the Aberdeen-Angus Cattle Society realises this by providing society members with greater returns on their investment in genotyping” says Brad.

What is Single-Step BREEDPLAN?

Single-Step BREEDPLAN adds a further source of information to the calculation of EBVs and accuracy, with genomic information incorporated simultaneously with pedigree and performance data. The evaluation takes account of each animal’s actual genetic relationship with all other genotyped animals, including those in the reference population. The reference population is the set of Aberdeen-Angus animals that have genotypes (SNP data) and phenotypes (performance records) for each particular trait.

SNP data is now being used along with pedigree and performance data to calculate BREEDPLAN EBVs and accuracy “in one step”. This applies to all traits in a multi-trait model combining birth, growth, fertility and carcase traits. As such, SNP data provides additional information in these calculations by accounting for the true genomic relationships among animals and how the SNP information relates to the performance records for each trait in the analysis. An important feature of the Single-Step BREEDPLAN approach is that complete use is made of the high density of genotypes recorded by Aberdeen-Angus breeders in the UK.

What are the advantages of Single-Step BREEDPLAN?

There are advantages that come with genomics and the Single-Step BREEDPLAN model. When young animals are genotyped at an early stage in life, they can achieve higher levels of EBV accuracy earlier in life – especially for traits expressed later in life – than is possible with a conventional (non-genomics) BREEDPLAN model. This equates to greater accuracy of selection decisions, at an earlier stage in the growth of animals, for Aberdeen-Angus breeders. Furthermore, for breeders with small herds, 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 accuracy – via their relationship to the wider genotyped and performance recorded population.