Since 2018 Simmental breeders have significantly increased their use of genomic testing and research for single-step Breedplan analysis is under way.
According to Southern Beef Technology Services technical officer Boyd Gudex, more than 2700 Simmental cattle, male and female, but predominantly sires with progeny of their own, have now been genotyped with chips suitable for potential inclusion in single-step Breedplan.
"At the start of 2018 there were less than 250 Simmental genotypes and in two years the breed has increased their genomic testing more than 10 times, which is very impressive," Dr Gudex said.
"The Simmental breed is building its reference population to enable the research to start and to allow genomic evaluation to occur.
"Four herds which have significantly contributed to the genetic evaluation with more than 100 animals DNA tested each, include the Woonallee, Bonnydale, LCS and Wormbete studs."
Leading animal geneticist Rob Banks from the Animal Genetics and Breeding Unit, based at the University of New England, Armidale, NSW, said although the Simmental breed was making solid use of Breedplan, there was scope for the breed to be making significantly faster genetic progress.
He said both more performance recording and the use of genomics could help achieve that.
"Approximately 5000 Simmental animals per year are submitted for evaluation and trait recording has remained steady with the main trait groups of weight, fertility and carcase.
"Genetic testing in the breed has focused mainly on horn or poll and coat colour.
"The breed's genetic trend is positive, but ideally would be higher."
Dr Banks said to make the most of the opportunities from genomics, a large enough reference population was required.
"The reference population refers to those animals that have performance records and a genotype, and is essential to enable detection of the DNA patterns related to superior performance.
"Without a reference population that is relevant to the current population, genotyping to obtain reliable estimated breeding values (EBVs) cannot work.
"It's also important that the reference population animals are recorded for the traits important for profitability in the beef value chain.
"For example, if the only records you have are weight traits, then you can only get useful genomic EBVs for weight traits with a genotype."
Dr Banks said the key requirement for single-step Breedplan analysis was a sufficient number of animals phenotyped.
"Initial testing of the strength of the Simmental genomic reference population has started, but it is likely the research work will continue this year.
"One aspect of the analysis is understanding the quality of the genotypes, and whether they are straight Simmentals, or include crosses.
He said to enable maximum genetic progress, all animals in the breed's reference population should be recorded for the traits that contribute to profit.
"To maintain a useful genomic reference population, it is necessary to record and genotype 500-1000 new animals per year, making sure they are being recorded for those traits."
But Dr Banks also emphasised single-step analysis was not a substitute for solid performance recording and making selection decisions using EBVs.
