Heading to the polls with new genetic horn test for cattle
This is important for the Australian beef industry as bruising is estimated to cost it A$30 million a year–or about A$4 per animal at the point of slaughter–with horns identified as the major contributor.
Using visual selection it could take 30 years to achieve an all polled cattle herd and the more recently available poll gene marker test has reduced that to four to eight years. But now it looks to be further fast tracked.
The improved test, which uses additional markers will be up to 99% accurate across all breeds, and will replace the present Beef CRC-developed gene marker test which is already achieving better than 90% accuracy in Brahmans and 72-74% accuracy in Charolais, Droughtmaster, Hereford, Santa Gertrudis and tropical composites.
The Commonwealth Scientific and Industrial Research Organisation’s Dr John Henshall, who is leading the project, funded by Meat and Livestock Australia, to refine the test, said the other good news is that research shows that being horned is a stand-alone trait.
“Being horned or not is similar to eye colour in humans, it has no influence on any other traits,” he said.
“As long as people are considering all traits that are important in their herd when selecting bulls, in addition to polledness, there should be no negative effects."
Henshall said that this, combined with animal welfare concerns and significant production cost savings, are the major drivers for change.
“Producer interest in the gene marker test, which has been commercially available from two providers for two years, has grown significantly over the past 12 months,” he said.
“Particularly in the northern beef industry, anecdotally we’re seeing a strong shift in attitude and increased demand for polled bulls, particularly those that are homozygous [carry two poll alleles as opposed to one poll and one horned, known as heterozygous].
“We can discriminate between animals with one polled allele or two polled alleles 90% of the time in some breeds, but only 50% of the time in others [such as Limousin].
“Even then, there is some uncertainty, there might be a one in 10 chance the test is wrong–similar to a progeny test with five calves.”
Santa Gertrudis breeder Burnett Joyce is not one to do things by halves so when he and wife Louise decided to transform their herd to polls it was full steam ahead.
The couple, who run a 1,000-cow, performance-recorded stud herd in Theodore, Queensland, had been visually selecting for polledness for eight years; however, despite their best efforts, had only managed to achieve about 20% polls in their herd.
“It was very difficult to fast-track progress because we found the cull rates in the polled cattle were much higher,” Burnett said.
“Historically, breeders have selected polls for that one trait and not applied the selection pressure that’s been on horned cattle. We’ve refused to lower our standards so if it was polled and didn’t withstand our other selection criteria, we didn’t keep it.”
Burnett and Louise produce about 300 bulls for sale each year and, since adopting the poll gene marker test during its validation process about four years ago, now offer every bull for sale with performance figures and its polled status.
“Our clients are demanding this information so they, too, can fast-track their conversion to polls,” Burnett said.
“We should soon be able to achieve an 85-90% poll calf drop from bulls selected using the poll gene marker test.”
“We need to be proactive and have industry-created solutions to dehorning, rather than waiting for pressure to be applied,” Burnett said.