O'Brien Dohne Merino and Poll Merino

2026 Sale Team

Videos:

• Lots 1-25
• Lots 26-50
• Lots 51-75
• Lots 76-100
• Lots 101-125
• Lots 126-141

Sale rams – Excel printable version includes ASBVs

Sale rams, all data. in downloadable excel with links to YouTube Videos

Inspection of Sale Teams invited, just get in touch.

M: 04 one 9 772 one 73 (Darren – DOB)

O’Brien Poll Merino’s offer to help with flock profile testing

A flock profile testing involves DNA testing 20 randomly selected lambs and will give you an ASVB value on numerous traits, that will enable you to establish what traits in your flock need improving and what are your good traits

Click here for a detailed explanation of flock profile testing.

Get in touch to find out more.

Darren and crowd at Flock Profiling and Genetics Day with Nathan Scott, Achieve Ag.

About us

O’Brien Dohne Merino and O’Brien Poll Merino studs are run by Darren O’Brien and Jodie Reseigh-O’Brien situated in the Kyancutta district of Eyre Peninsula, SA. Kyancutta is renowned for its hot and dry summers with this in mind we breed sheep with excellent nourishment and staple length. We have a stud ewe flock numbering approximately 1100 adult ewes across the O’Brien Poll Merino and Dohne studs.

2026 Newsletter

It’s that time of the year to update our clients and hopefully a few new ones to what we have on the go at O’Brien merino, as you guess not much in the sheep world stands still or the world in general for that matter.

A good sheep now days is not the one of the 1990s with a ribbon around its neck it has to have so much more to keep you ahead of inflation, that means you have to be increasing production or deceasing costs and labour by at least 2.5 % year to break even, while this seems impossible, we are doing it and have done for the last 10 years. This is why ASVBs are so important, one to know what you are buying to improve your breeding objectives and two be able to track genetic gain in all the traits that matter to your bottom line. Below is a table of a few important traits and our genetic gain over the last ten or so years, we can do this to check where we are going on every trait.

By having full pedigree and are fully genomically tested our stud has been able to partner with various trials and projects to help enable the sheep industry stay ahead of the game.

We are working with two methane projects:

• Firstly, with University of New England (UNE), NSW to collect data on the methane our ewes are omitting. This will be undertaken in chambers, we will be testing 500 ewes from 15 different sires in a months’ time (if you are keen to know more or have a look let us know).
• The other project is a PIRSA demonstration site, where we are endeavouring to reduce our methane omissions by increasing production. Our aim is to increase our weaning rate in adult ewes from 130% to closer to 150% while increasing early growth and increasing lamb survival by using ASVBs and a few other tactics. A couple years ago, we worked out that our WR and ERA ASVBs were only average and needed more attention, so we are aiming to push them into the top 20 percentile in the next 3 years as part of the project.

We have some methane data on some of our rams that have been in the resource flock to help us understand how we can use this data. While many of you will say why bother with methane, me included (just ask Jodie). Not until I started to understand what we are wasting, it is energy and you pay a fair bit for that in a dry times/drought, especially when you have to buy feed in. This trait or data (however it is reported will probably be linked positively to feed conversion which is the main trait we need and will get in the next few years) remember that 2.5 % per year gain!

We are also working with Adelaide University on a sheep heat stress and resilience trial and demonstration site:

• Over previous years working with them, they have identified the importance of using ADE and melatonin at joining especially when ewes haven’t seen green feed for a while.
• This year heat loggers were put in ewes to record their body temperatures to see if has an influence over reproduction outcomes, the twins out of this group had 168% survival a tailing so hope something comes out of it
• Another part of the project is making the sheep and our farming system more resilient.
  • The sheep part is about showing the importance of condition score in both genetics and management. Of course I am more interested trying to quantify the genetic CS importance, a no brainer in my eyes.
  • The farming system part of project revolves around making our marginal cropping country that has frost, salt, stone and sodic soils as well as rainfall issues (country not suitable for lentils) more viable by intensely running sheep on it. We have sown Cereal rye and have been using it to wean lambs onto and carry ewes over summer no matter the rainfall year with success. University of Adelaide and AIR EP are monitoring and putting some numbers around it to see where it sits in comparison to wheat and medic pasture. We have a couple of paddocks that have had cereal rye for 6 years straight without disease or production loss. “Turning pigs’ ear into pork chops” I reckon.

We are also part of an udder project at University of New England, the last two years I have collected udder data on all ewes about 1200 when you include ewe lambs. Scoring the udder shape, teat placement and teat size, in time I hope we will see the influence over lamb survival and maternal weaning weight. At the moment, I think teat size is the most important allowing just born lambs ease of suckling, hence aiding lamb survival and looks heritable, another one percenter!

We have identified that there is a 10 to 12% difference between sires for twin survival and think we have worked out some traits to focus on to help fix this

• Other tactics to increase lamb survival
• Know your paddocks – some paddocks are just not great for twin survival whether it be distance to water, wedgie or fox damage, you can lamb singles in those paddocks without any trouble, but they are not great for twins – start recording how paddocks stack up!
• Joining periods – using shorter joining periods is a game changer particularly when feed is in short supply. Makes for easier tailing and weaning, matching the ewe to her feed requirements. It also allows you to back up (maybe with a terminal) the first mating if you are worried about missing some. The payback on shorter mating (i.e. putting rams in and out on time) in ease of management is pretty good.

When you can improve your lambing to ~130% lambing, there is a lot of the selection pressure comes from the ewe replacements, with only about 25% of the drop are retained as replacements (rest sold for $$). This also places post weaning weight near  the top of the breeding objectives.

Table. Results from our 2025 Drop, post weaning weight (PWT) compared to raw data

PWT Percentile band ASVB	Number in 25 drop	Grams per day average	Average live weight @240 days	Carcass value @240 days @ $4.83 per kg live
Percentile band 1 to 10%	337	250.5 g	60.11 kg	$290.34
Percentile band 11 %to 20 %	248	235.7 g	56.57 kg	$273.54
Percentile Band 40% to 60 %	194	216.95 g	52.07 kg	$251.49

Meaning if your ewes sit in the 50% band for PWT and use sires from the top 10 % band, one cross is an Extra $20 in your pocket

Again, all small gains to keep up with inflation! You can use ASVBs across any trait to work out the genetic gain you can achieve

We also have got the new Neogen Immunity test done on all current ewes and any sires that have had an influence in our stud and will come with all progeny tested going forward. This test is expected to identify sheep that have better immunity to various diseases and have better recovery when they are challenged. I suspect vaccines will work better because of more antibodies produced and also hope it identifies the ewes that give the lambs more antibodies in the first milk to aid survival!

Again, keep adding the 1 percenters!

Over the last year we have had two sires in sire evaluations:

• O’Brien 230173 in the SA Sire Evaluation and
• Wallaloo Park 220960 in Balmoral Sire Evaluation

Both sires have performed well in the Sire Evaluation and as they did in the stud and were amongst the trait leaders in many traits and 230173 classed up pretty well with a low percentage of culls.  Most importantly, they benchmark our other sires and give us an indication on how they perform in different conditions and management and are scored and classed without identification of who the sire is, a valuable trial.

Through the use of ASVBs both sires have been super seeded with the same standout traits that these rams were good at, don’t stand still, there is no improvement in standing still! And as Jodie would say it enables me to back up the bull shit

We aim to benchmark our mob and our sire team by entering sires in sire evaluations across Australia of the 700 odd sires evaluated across Australia, we own

• 4 sires in the top 50 of the 780 rams in the SM index (Sustainable Merino Index)
• 3 sires in the top 50 of 700 rams in the important ML index (Merino Lamb Index) including the top indexing ram – WP220960, which we are currently using as well as its offspring and are using offspring of other high-ranking rams on this list

By trialling these rams, we get an accurate benchmark of where our sires sit and where we can push to improve. More details and the results can be found in https://merinosuperiorsires.com.au/wp-content/uploads/2025/10/Merino-Superior-Sires-31-21-September-2025-All-Time-Top-50-Sires-1.pdf 

This year we have decided to put the toe scores on the placards and have used photos and videos of rams untrimmed on our web site, for a couple of reasons, we have had a ram OB221124 in the foot health trial where they have scored feet structure, toe growth and the instance of foot abscess and foot rot. It seems that toe growth and shape have the biggest influence on foot health, so in a wetter area (That’s everywhere this year) it seems a no brainer to put a bit of selection pressure on it. The other reason the last couple of years ewes have spent a fair bit of time in containment resulting in extra toe growth, one neighbour had to trim the whole mob (not a client or I would have had to help!) and I had to cull a few ewes when they came down the race. This is not a way to encourage young people into sheep production!

For those just starting out using ASVBs don’t make it complicated, set your breeding objective on what you want to improve and only work on 3 or 4 traits at a time. To work out where your mob sits, we recommend doing a flock profile it focuses your attention on traits that you are good at and what needs attention, don’t be afraid to ring and discuss breeding objectives decisions we play with ASVBs most days and don’t expect anyone who only has to look at them a couple times a year to be full bottle on them

My thinking is what ever trait you want to improve whether it be wool cut, fibre diameter early growth or weaning rate, place condition score above it, if a sheep can’t look after itself it’s going to have trouble with extra production when the pressure come on.

If where you buy rams isn’t recording and selecting for condition score, tell them to do so or find another stud that is. It needs to be an ASVB for CS and any other trait for that matter, that is the only way to make genetic gain, seed stock producers that use raw data don’t paint the whole picture, there is too much interference from other things like age, age of mother, birth type, and group (some get preferential treatment).

A reminder to people who have done previous flock profile tests you have to update them in your ram select account to have the breeding values in the current run; i.e. be able to compare with the rams you will be buying and using this year. While you are in ram select put in previous rams purchased their ASVBs will be updated automatically.  Give me a call, am happy to talk you through how to do this.

As usual there is a bit going on here.

We welcome enquiry and have rams close by for inspection at short notice, I also can class your flocks if you need that to be done. We have been using eID and auto drafting etc for about 15 years so can help in that area of performance recording if you want help getting started, by the way that’s another project run by the drought hub and Adelaide uni we are to be involved in in some way.

We will be attending:

• Southeast Merino Field Day at Keith

Our sale is at the Wudinna Showgrounds Thursday the 30th July, offering 140 rams.

Regards

Darren and Jodie