MEAT and Livestock Australia (MLA) has taken the bull by the horns to release a new and improved polled gene marker test.
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The advanced accuracy and greater application of the test across breeds delighted guests at an MLA-hosted beef industry breakfast last Friday.
Replacing the previous Beef CRC-developed test launched in 2010, the project team of Dr John Henshall, CSIRO, Professor Bruce Tier, Animal Genetics and Breeding Unit, University of New England and Dr Emily Piper, University of Queensland, revealed additional markers that rendered the new test nearly twice as precise across various breeds.
Dr John Henshall said the first test was initially developed on Brahmans and based on a single DNA marker, whereas the new test included information from a further nine markers.
"The new test uses additional markers, increasing the proportion of animals for which the test identifies the true genotype," Dr Henshall said.
"Using information from additional markers allows more accurate tracking of genes and their association with polledness."
He added that while the idea of breeding for polled was nothing new, without genetic intervention, the process could take up to 30 years. "You can sometimes determine an animal's genotype from its pedigree, but it is more efficient to determine the poll status of bull calves early," Dr Henshall said.
While the test had come leaps and bound in the last few years, questions fired at the developers from the beef producers in the room highlighted the ambiguities and proved the test still wasn't perfect.
"Some alleles (alternative forms of gene) associated with polled in some populations are associated with horns in others," Dr Henshall said.
"Although as our sample size increases, these ambiguities will diminish."
He said sample quality was vital and sample size was not the only variable to determine outcomes.
"We have found that the phenotypes (the trait as observed in the animal) are not always reliable," he said.
"At the time of branding it can be very difficult to determine the difference between horns and scurs in particular."
However, he said the new Australian poll gene marker test would accurately determine if an animal was homozygous or 'true polled’ - carrying two copies of the polled gene - as opposed to heterozygous with one copy of the polled and one of the horned gene.
Dr Henshall said understanding the genotype of an animal would drastically reduce the requirement of dehorning in its progeny - a practice deemed to be costing the industry millions of dollars
a year.
"Dehorning has been shown to be more labour intensive, more painful, causes wounds that take longer to heal, incurs more risk of secondary infections and results in a higher mortality rate among calves," Dr Henshall said.
MLA managing director Scott Hansen said this combined with animal welfare concerns were drivers for investing in the research and development of the test.
"This provides cattle producers with an additional tool in assisting them select the right genetics for their herds, in this case a tool to help reduce costs of dehorning, to help reduce production losses and mortalities associated with dehorning, and with reducing downgrades of their product due to bruising and hide damage," Mr Hansen said.
He said the continual improvement and adoption of the test by producers should see benefits flow back through the farm gate.
Taking hair, blood, tissue or semen samples, the test will be available from the Animal Genetics Laboratory at UQ and Zoetis Animal Genetics. Producers can contact the providers directly, or through their relevant breed society.
