GENOMICS is close to becoming a “mature technology” in the beef industry, but the challenge remains developing tools to make the most of the test results, according to University of Adelaide School of Animal and Veterinary Sciences professor Wayne Pitchford.
He is excited about working with innovative breeders on several projects that combine genotyping results and the additional commercial performance data collected.
Professor Pitchford says by analysing single DNA base variations, genomics can “fill a gap” in hard-to-measure traits and generate pedigrees on commercial animals not often recorded.
“Normal genetic evaluation requires the ranking of animals all born and raised together and needing to know the pedigree and in many studs all the bull calves are kept entire, which makes carcase information difficult to obtain,” he said.
Genotyping not only gives more accurate parentage verification, but even which regions of the genome have been inherited by the progeny.
- WAYNE PITCHFORD
“Genotyping not only gives more accurate parentage verification, but even which regions of the genome have been inherited by the progeny.”
Prof Pitchford says for the past two years, the University of Adelaide has been working with large commercial clients of Hereford studs across Australia, collecting Meat Standards Australia carcase grading data on more than 2000 of their steers.
Part of Meat & Livestock Australia’s fast-track project, the work is due to finish in June.
Prof Pitchford hopes it will set up a model for the ongoing flow of carcase information into breed databases.
It should also improve the accuracy of traits such as lean meat yield and intramuscular fat.
The university’s work also involves generating customised breeding values for an elite Wagyu breeder aiming to improve carcase quality, as well as helping tropical composite cattle stud Popplewell Composites with its efforts to lift the reproductive potential of its females.
“All of the programs combine more accurate trait measurements (phenotypes) and genomics, which gives a more accurate description of genetic relationships than pedigree to achieve more accurate estimates of breeding values,” he said.
Qld breeder Greg Popplewell, who has developed the tropical composite across the past decade, had the foresight to collect tail hair samples from every animal he has ever bred.
Through genomics, Prof Pitchford says Mr Popplewell has been able to identify heifers more likely to get in calf as yearlings and get back in calf sooner.
“Most tropical cattle are not joined until they are a bit over two years of age but everything is joined as yearlings for a two-year-old calving,” he said.
“He (Mr Popplewell) has got bulls that will breed heifers that will calve a month earlier than Brahman bulls.”
Prof Pitchford says commercial bull buyers should be encouraging their seedstock supplier to genotype animals in their herds to improve the accuracy of estimated breeding values available in sale catalogues.
But he also sees value in genomic testing for commercial herds, with some already genotyping heifers to identify replacements that are genetically superior.
“Often heifer selection in commercial beef herds is reasonably ad-hoc and which ones are bigger rather than which ones are genetically superior, but if they are going to be in the herd for a long time it may be a value proposition,” he said.
“Breeders who sell females may also be able to gain a premium by genotyping those females.”
