"IF you are spending big money on one ram, how can you be sure of what impact it is going to have on your flock?"
That was one of the questions raised by Merino Lifetime Productivity (MLP) Pingelly site manager Bronwyn Clarke at the Sheep Easy event at Williams on August 11.
Dr Clarke provided more than 180 attendees of the event with an update on the 10-year MLP project which was started in 2015.
The $13 million project was designed to capture lifetime data across diverse environments and Merino types to help better understand and deliver ewe lifetime performance outcomes for the Australian Merino industry.
It is conducted across five different sites, including Pingelly (WA), Balmoral (Harrow, Victoria), Merinolink (Temora, New South Wales), New England (Armidale, NSW) and Macquarie (Trangie, NSW).
At the Pingelly site, the 2016 ewes were mated to a team of rams naturally for the first time in 2018.
Tissue samples were collected from the progeny for DNA and to identify their parents.
"In 2018 we used nine different rams that we put in the paddock with the ewes," Dr Clarke said.
"Almost half of the progeny were sired by three different rams.
"Similarly in 2019 one ram didn't do any work while two rams did half the work.
"This is natural mating, but clearly some rams are working harder than others."
Results were similar in the site's 2017 ewes, which revealed two and a half rams were "doing all of the work".
But were they the same rams?
According to the results one ram that sired 18pc of the progeny, also sired 19pc and 21pc for the following two years.
Equally there was a ram, which had 8pc of the progeny in 2018, followed by 4pc and 2pc.
"He is not working at all," Dr Clarke said.
"So the big question is: If you are spending big money on one ram, are you getting a 20pc or a 2pc?
"How do you know?
"Similarly if you are down a ram and bring one down from the paddock, is he a 20pc or a 2pc?
"His genes could have a very big impact on your flock."
Dr Clarke added that the data hadn't been seen before as naturally mated commercial flocks don't usually identify pedigree.
The trial work was using DNA to get the pedigree for these animals that were naturally mated, which doesn't usually happen in commercial flocks.
"This is really interesting and impactful data that makes you think about the sort of rams and the rams you buy and your ram breeding teams," she said.
"They have a very big impact, very quickly on the flock or no impact at all."
Dr Clarke also shared data from the trial, which hadn't been published before, on twin lambs.
In 2016, the MLP ewes' first drop of lambs included 48 lots of twins or triplets, 31pc of which had different fathers.
"So 65pc of those twin lambs had different sires," Dr Clarke said.
"Now I saw that and thought the data was wrong, so I questioned if there was something wrong with the DNA pedigree.
"As our rams are quite closely related to each other, with some being brothers, I thought maybe the DNA wasn't picking up the differences between the rams."
The data however was correct, as in following years similar values of 56pc and 52pc were produced.
Dr Clarke also looked at other trial sites and the 2017 drop, which used the same rams and again had similar numbers of 54pc and 61pc.
She said the take-home message was not to take a tissue sample from one set of twins to save money because the data would be very inaccurate.
Meanwhile, in terms of reproduction, three different site's data from ewes born in 2016 were analysed, including the average number of lambs weaned over their three-joining opportunities.
This revealed that over three years, the average number of lambs weaned per ewe joined at MerinoLink site was 106pc, Balmoral 94pc and Pingelly 114pc.
That was with no culling.
"So what would happen if we culled those dry maidens?" Dr Clarke said.
"Well at MerinoLink there were 53 dry maidens.
"So if we took those out of the data set and then looked at our average weaning rate, what we found was that the weaning rate was higher at 111pc.
"Over at Pingelly we didn't have as many dry maidens and it didn't make much of a difference at 115pc.
"What we can see is that the highest weaned percentages occur at different places in different environments."
However, this did not take into account the economics of culling hogget ewes, looking at the production of older ewes and replacing them with the younger ewes.
Dr Clarke said each scenario would be different in the different environments of sites, for example Pingelly versus MerinoLink.
She said they may also be different for different Merino genotypes.
"Recommendations may be different for faster maturing genotypes - that might have no dry maidens and are getting pregnant early - compared to some wool genotypes.
"That's why we have to wait until we get the data set to look at all the options."
The MLP is a partnership between Australian Wool Innovation and the Australian Merino Sire Evaluation Association.
