The number of polled Merino rams has spiked dramatically since the introduction of DNA testing, as producers embrace the workplace safety and animal welfare benefits of hornless sheep.
The Cooperative Research Centre for Sheep Industry Innovation (Sheep CRC) first commercially released its Horn-Poll DNA test in 2012, following several years of trials with producer participants.
New data shows the number of polled rams sold and the volume of semen sales from polled rams began growing dramatically at that time, as producers sought out breeding stock that were safer and easier to handle than their horned equivalents.
The ‘Top 20’ studs identified in the NSW Stud Merino Breeders Association publication ‘Top Sire 2017-2018’ reported sales of 16,000 doses of semen from polled rams in 2016, up from less than 1000 in 2008, and almost 5000 polled rams were sold in 2016, up from approximately 1500 in 2008.
“We knew that commercial sheep breeders wanted polled rams but they needed more information than the physical absence of horns before investing in polled semen or polled rams. A lot of poll rams are carriers as the recessive horn gene, so the genomic test was essential to driving this change in the Merino industry,” Sheep CRC chief executive James Rowe said.
The test for the horn gene is based on a set of markers that are close to the gene and when using a PP tested rams there is a 97% probability that male progeny will be free of horns and a 99% probability for female progeny.
Western Australian mixed farmer Rob Egerton-Warburton is a participant in the Merinotech breeding group, which took the decision to embrace pure-polled genetics in 2014 and since then has almost completely removed the horned gene from its flocks.
“We made the decision to transition to a polled flock once the technology became available and we could be sure that the genetics we were selecting weren’t going to take our flocks backwards or retain any horned genes – before DNA testing that transition would have been a hit-and-miss,” Mr Egerton-Warburton said.
“The DNA testing for horn-poll and a range of other genetic traits has been the key making that transition without too much disruption to our breeding program.”
Mr Egerton-Warburton said the technology has also made the farm a safer place for both workers and animals.
“From an OH&S point of view, polled rams are much easier to handle in the race and this is really important for the safety of our workers and for our animals at a time when finding experienced stockmen is quite difficult,” he said.
“While we still see some flystrike as a result of polled rams fighting and opening each other up, the damage is nothing like what it was with horned rams in the flock. In the past we had to keep our horned rams apart from the polled rams because they had such a significant advantage when they fought - now our rams are left to their own devices.
“We also used to have to remove the tips of the rams’ horns each year - that was a terrible job. And rams used to get caught in the fence with their horns and it wouldn’t take long on a hot summer’s day for them to lose their life. We’ve been able to transition away from all of that very quickly through DNA testing.”