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. The wheat and sheep area is renowned for its hot and dry summers with this in mind we breed sheep with excellent nourishment and staple length.

The stud ewe flock is approximately 1100 adult ewes across the O’Brien Poll Merino and Dohne studs. We also mate ewe lambs at 7-8months of age, this means we are doing a full pedigree and data management on over 1300 lambs.

Darren O'Brien Jodie Reseigh-O'Brien

As we have learnt how to and what data is important to our breeding objectives. We are proud of the data we collect, which means higher accuracies for the ASBVs we measure, meaning you will know how the progeny of our rams will perform.

Over the years we have bought a lot of rams without ASBVs and as we have been able to individually do single sire mating and good pedigree, we think the rate of failure to perform in certain trait that you were buying the ram for without ASBVs (e.g., guess work) can be as high as about 3 out 4 rams progeny not coming up as expected. Hence our push to get our ASBVs as accurate as possible.

When looking for a stud that is going to fit with your breeding objectives, it is worthwhile finding out what they actually measure otherwise it is on an opinion or guess.

So here is what we do. We are happy to collect and provide data to our clients along with ASBVs.

  • Birth date
  • Pedigree determined by genomic DNA tests
  • Early breech wrinkle and early breech cover scored
  • Weaning weight
  • Early post weaning weight
  • Yearling weight
  • Hogget weight
  • Adult weight
  • EMD and Fat scanned at Post Weaning 6/8 months when we need the animals performing not at 15 months on full feed
  • Yearling and hogget staple length
  • Fleece weights at yearling and hogget and adult
  • Micron tests at Yearling, hogget and Adult stages
  • Yield test at Yearling
  • All rams and ewes close to entering the stud are visually scored for 20 different wool and structure traits to identify what is is good and what needs attention ,as well it identifies how sires are performing
  • All yearlings Scored for belly wool length and belly wool creep (mainly for our own use)
  • Reproduction date is submitted to sheep genetics include Pregnancy scanning for singles and multiples, mate weight and what ewe had what lamb.

We have been going hard on pastern structures because Dohnes opened our eyes up to how much pressure is put on them with fast early growth. Now with many more studs selecting for early growth and with accurate ASBVs for this trait. We feel this will be an easier improvement to make but they still have to walk around the paddock as a 5 or 6 year old. To this end 2020 drop onward has been scored for pastern structure and feet direction and roll both back and front, this also opens eyes to which sires are performing as you want, and while they were in the crate they were scored for hock structure and wool colour and importantly Butt shape for higher meat yield.

Our shearing consists of 2 nine month and 1 six months to keep out of the way of lambing, seeding and harvest, and Dohne were struggling to make 60 mm at 6 months, but as one of 2 or 3 Dohne studs measuring, submitting and selecting for staple length the improvement in this trait is well on track.

The biggest help to our breeding selections, accuracies will come about in early 2021 with our Dohne data being in both the Dohne and the Merino analysis in Sheep Genetics. This will provide accurate ASBVs on the Dohne influence part of our flock and give a direct comparison to all our poll Merinos, and a comparison to many more thousands of sheep (Yes, exciting as the only Dohne stud doing so).

Our stud has a few other rules we like to adhere to:

  • We don’t use any body strike fly prevention, as will hide an issue if present.
  • We do use Clik on the udder on one shearing cycle when ewes are lambing at 4-5 months wool growth.
  • We lamb twin in as small mobs as we can provide and are ageing foetuses to aid in getting the birth date right.
  • We do feed rams up in a feedlot situation in the last 4 months before ram sale. While this shows their full potential there are positive and negative to this. The main reason we do it this way is we feel it is better to run extra ewes and lambs in good paddocks that the sale rams would need. This time of year can be hard to find feed if we get a late break. A lot of our clients use feedlots or containment areas to either look after their soil or finish lambs or cull ewes, it is not far from normal district practice.
  • We have stopped mulesing, mainly if clients want to stop, it makes ram selection easier for them.

Over the past few years we have entered various sires in the SA Sire evaluations, this enables us to put accurate ASBV numbers around sires we bought without numbers and to provide excellent linkage for our studs. Sires entered Ridgway Advance 150103 Caroonboon 181395 , O’Brien Poll 190455 and O’Brien 201166 ,all have been trait leaders for growth and wool cut and the independent sire evaluation data has shown to have great collation with our sires ASVBs .Therefore backing up the accuracies of our sheep genetics data