Ag News

DNA testing, no more guessing

  • By: "Prime" Ag News
  • Jan 16, 2018

DNA testing has taken the guesswork out of breeding for Victorian sheep mixed farmer Todd Martin, who now has a clear picture of how his flock compares to the rest of the industry and the decisions he needs to make to improve its performance.

Mr Martin was a participant in a pilot trial of the DNA Flock Profile Test conducted earlier this year by the Cooperative Research Centre for Sheep Industry Innovation (Sheep CRC).

The test provided Mr Martin with the reinforcement he needed that his flock improvement strategy was taking him in the right direction but it also provided him new insights into how to fine-tune his decision making to stretch his production even further.

“We undertook DNA flock profiling for two main reasons: one was to get a gauge on where we are at the moment with our breeding program and to assess whether we are achieving our breeding objectives; and the second one going forward was to help us through RamSelect Plus to assess the potential impact of various options for ram purchases on the improvement of our flock,” Mr Martin said.

“We found it was a really good way to get some objective information to tell us if we were on the right track or not and it showed that there are still areas that we need to work on and that was exactly the point of taking the test.”

The Sheep CRC’s DNA Flock Profile Test involves randomly sampling 20 young ewes for DNA testing, with genetic links then identified with animals of known breeding values from the Information Nucleus database.

These linkages support a prediction of the flock's average breeding values, which are then scaled to Australian Sheep Breeding Values (ASBVs) for major Merino traits, such as yearling weight, fleece weight and fibre diameter and well as the indices for Fibre Production, Merino Production and Dual Purpose.

Mr Martin runs a self-replacing Merino flock of 1500 ewes at Loddon Downs, located 85km north of Bendigo, Vic. The operation features a mixture of dryland and irrigated country, with about 70% of the business devoted to cropping and 30% to sheep.

He runs the ewe base to produce prime Merino lambs and crosses cull ewes to Terminal sires – as such, his breeding objective is based around the business’s profit drivers of growth rate and fertility.

“The DNA Flock Profile results showed us that we were probably around the top third of the database for our carcase traits, whereas our wool traits we were down around the middle of the database,” he said.

“So moving forward that’s something we need to be aware of. We don’t want to take our eye of the wool traits altogether, but we’re heading in the right direction of where we hoping to be in terms of the carcase and fertility traits.”

Mr Martin is currently marking 130% lambs and weaning at 40 kilograms liveweight at 13 weeks – which equates to a growth rate of more than 300g/day.

“I definitely think we have potential in the future to be consistently weaning 150% lambs at marking in future years, and cutting 7-8kg of 19m wool from the ewes at shearing – we haven’t got a great distance to go and we definitely feel that the combination of good management, DNA Flock Profiling and ram selection using ASBVs will provide the keys to achieving those goals,” he said.

“Later this year when we select new rams for the ram team, we’ll use RamSelect and we’ll be able to assess those potential sale rams and see what likely effect they will have on our Flock Profile going forward,” he said.

Mr Martin said he would be actively looking for rams also carrying DNA test results, which he believes will add an extra layer of precision to the Australian Sheep Breeding Values (ASBVs).

“I’d say to any other commercial producer to have a good look at DNA Flock Profiling because as more and more stock are DNA tested in the MERINOSELECT and LAMBPLAN databases it will give you more options for your ram purchasing decisions,” he said.

“We plan to use the DNA Flock Profiling every three to five years in our business to identify changes we need to make in our ram selection and to keep our understanding of our flock accurate and up to date as we know that our flock’s genetic profile will change as a result of the rams we select this year.

“The test will either reinforce what you’re doing right or identify areas you need to change.”

Picture - David and Todd Martin, ‘Loddon Downs’, Durham Ox, Victoria, discuss the results of their DNA Flock Profile test with the Sheep CRC’s Tom Granleese.