Selecting Rams - using Australian Sheep Breeding Values (ASBVs)

When selecting rams for a commercial enterprise the first step is to set your breeding objective. Spend a few minutes to write down precisely what you are aiming for, including the levels of performance and by when you want to achieve it. Find more information on setting a breeding objective.

Because the most effective way to select for a trait or characteristic is to directly measure or assess that characteristic, you should buy rams from a stud that objectively measures or collects scores (using a standardized system) for the traits you wish to improve.

For instance, staple strength can be selected with much higher accuracy if the stud directly measures staple strength on its rams, rather than just having the ASBV calculated from related measurements such as fibre diameter coefficient of variation.

However, the ram’s own performance is only part of the picture. What you see in the ram isn’t necessarily what you will get in the progeny because much of the ram’s performance is a result of the ‘environment’.

Nutritional differences between animals are a key environmental element and not only come from what they eat, but whether they were born or reared as a twin or their mother was a maiden ewe—giving them less nutrition during pregnancy and lactation than for a single lamb and/or from a mature ewe.

Also, climate, disease and management differences will affect how they perform.

If you know these environmental factors for each individual, and if you have been able to inspect all of the animal’s relatives and see their performance data, you’d be able to predict very accurately, how the progeny will look and perform.

However, this is not practical for you to do, so studs that provide you with Australian Sheep Breeding Values (ASBVs) already have this information taken into account. DNA, Pedigree information, management groups, data from relatives and relationships to rams used in the stud and elsewhere are all accounted for and very important when calculating Australian Sheep Breeding Values.

Importantly, you can accurately compare rams from different studs (whether at opposite sides of the country or having had quite different management) if they both provide ASBVs for the same trait.


How do you incorporate ASBVs with your visual selection?

Choosing your stud(s).

The last decade has seen great changes in the information some studs offer and ram buyers have become more discerning. Gone are the days of believing that a ram simply throws back to the average of the stud, as more detailed analysis has shown that there is considerable variation across rams within a stud.

Comparing rams from different studs is easy and accurate when they have ASBVs because the differences associated with nutrition and management have been removed.

  1. Choose one or more studs that have the type of sheep you are after and which provide ASBVs directly measured on the traits you consider are important to your production system.
  2. If the stud you are using does not currently provide ASBVs, ask them to do so. An increasing number of studs are now providing ASBVs because their clients have requested them.
  3. Ask for the ASBV data to be sent to you in advance—more studs are now providing this in sale catalogues and on the web (including links to their animals in LAMBPLAN and MERINOSELECT ). This is particularly useful to compare studs at the start of the sale season, allowing you to review the rams on offer from each to see whether one stud has more rams that suit you or whether there are individual rams you would like to inspect.
  4. Use to compare and rank rams across different studs or within your chosen stud.
  5. If the rams you are interested in are not appearing on, ask the stud to list them.
  6. Based on your review of sale information, choose the stud sales you will attend.
Choosing individual rams

Visual selection is still an important part of selection—particularly for wool sheep—because there are still traits of importance that are not available for selection using ASBVs.

  1. Choose the minimum level or range of ASBVs (or an index) that you will accept for each trait that is important to you.
  • For instance, you may choose a fibre diameter ASBV range between –1.0 and –2.0 microns, so as to keep your flock’s fibre diameter in the fine-medium range. On top of that you might want worm resistance and are willing to take animals that are simply “better than the average for all Merinos”. This is about –3% for WEC ASBVs.
  • Be realistic in the levels you set and the price you may need to pay, as many others will also want the higher performing rams.
  • Rams with lesser performance can be just as profitable for you providing you pay a correspondingly lower price, as the ram’s costs should also be included in your cost of production; likewise the best animals may not be the best value if they are too high a price. Use to rank rams according to your breeding objective.

2. Use the ranked list from to assist you on sale day. This way, you can then spend your time at the sale more thoroughly visually assessing the rams, instead of wasting time on poorer performing animals.

3. On sale day, follow your ranked list and visually assess only the selected individuals. Avoid viewing poorer performing animals, so you are not influenced by those that look good, despite their poor performance.


Practical Wisdom Notes / Fact Sheets

PW4.1 New Opportunities in Genetics and Genomics

In this series:

  1. Genomics and DNA testing: new tools for ram breeders to accelerate genetic gain
  2. Breeding towards a poll flock with the Sheep CRC Poll test

  3. Sheep CRC genomic test for Merinos —what are the benefits?

  4. Sheep CRC genomic test for maternal breeds —what are the benefits?

  5. Sheep CRC genomic test for terminal breeds —what are the benefits?

  6. Using Australian Sheep Breeding Values

  7. Fat and eye muscle depth in Merino breeding programs

  8. Benefits of Reproductive Technologies in  Closed Nucleus Sheep Breeding

  9. Merinotech: Strategies to achieve a 100% PP nucleus

  10.  Using selection decisions to improve ASBVs

  11. Genomic testing ram lambs helps increase rates of index genetic gain by 50% at Centre Plus

Products & Training Resources

ASBV Pocket Guide

ASBVs - A guide for ram buyers

Marketing your sheep with genetic data

Sheep DNA Testing Information

Reports, Articles and Presentations

Getting Started with Sheep Genetics

Sheep CRC Genomics Breakfast Workshop - LambEx 2012

News Releases

DNA Flock Profile test takes gut feel out of farming
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. Click Here To Read Full Article »
DNA Flock Profile cements the foundations for new flock
Developing a flock with the right mix of genetics can take generations to perfect, but DNA testing has put Geelong sheep and wool producer Jack Briscoe on the fast track to success. Mr Briscoe is only a year into breeding his own Merino flock after branching out from his sheep contracting business by cobbling together a mixture of 800 home-bred and yard-bought ewes as his breeding base. Click Here To Read Full Article »
RamSelect keeps track of flock performance at Parkes
The RamSelect app is not only assisting with better genetic decisions for the Dunn family of Parkes, NSW, but also assisting with their inventory management and industry benchmarking activities. The Dunn family, trading as Reedy Creek Partners, operates a mixed farming enterprise between Manildra and Parkes, and has been using the app since it was first launched in 2015 to assist with their ram selections. Click Here To Read Full Article »
Faster sheep DNA testing with new Australian GeneSeek lab
Sheep breeders using DNA testing to improve their genetic selections can look forward to faster turnaround times for test results thanks to Neogen Corporation’s decision to establish a genomic testing laboratory within Australia. GeneSeek Australasia, a wholly owned subsidiary of United States-based parent company Neogen, has acquired the assets of the Animal Genetics Laboratory (AGL), based at the Gatton campus of the... Click Here To Read Full Article »
Dramatic increase in early season searches on RamSelect
Inquiry for rams through RamSelect has never been stronger with a dramatic increase in the number of buyers searching the site so far this season compared to last year. More than 1129 ram searches were conducted on RamSelect during July, compared to just 154 at the same time last year. Click Here To Read Full Article »
DNA testing to drive new era of ewe competitions
The traditional ewe competition is set to enter the innovation era with the inclusion of DNA Flock Profile tests as part of next year’s Doug Bicket Memorial Ewe trial in Parkes, NSW. The Cooperative Research Centre for Sheep Industry Innovation (Sheep CRC) will provide DNA profiling for all flocks entering the 2018 competition, currently valued at $800 plus GST per flock, as a means of supporting improved genetic selection... Click Here To Read Full Article »
The predictive power of ASKBILL immortalised in song
An off-the-cuff comment and a spur of the moment decision to “have a go” have resulted in the sheep industry’s new predictive app, ASKBILL, being brought to life in song by Uralla musician Rhonda Brooks. Performed in a bush ballad style by Coffs Harbour musician Mal Winckle, the track is proving a popular addition to the ASKBILL website, helping to capture producers’ imagination as to the possibilities on offer... Click Here To Read Full Article »
RamSelect moves towards commercial business model
The popular RamSelect app will move to a commercial funding model ahead of this season’s ram sales, as a first step towards ensuring the genetic selection tool’s financial viability and availability to producers in the long-term. RamSelect Plus is an easy to use web-based application,, which allows ram buyers to find and rank rams based on Australian Sheep Breeding Values (ASBVs) that match their own... Click Here To Read Full Article »
Faster, more accurate DNA Parentage and Poll test to be released in July
Sheep breeders will have access to a faster, more accurate DNA test for parentage and poll/horn status from July, which also includes new features to detect a range of genetic defects. First launched in 2012 by the Cooperative Research Centre for Sheep Industry Innovation (Sheep CRC), the DNA Parentage and Poll test has proven very popular with sheep breeders seeking to improve their genetic selections through more precise... Click Here To Read Full Article »
‘Eye opening’ DNA Flock Profile delivers new breeding insights at Beechworth
DNA testing to obtain a genetic flock profile has changed the way Victorian Merino breeder Stuart Warner not only looks at his flock, but how he will approach his genetic selection decisions in the future. As a registered deliverer of Bred Well Fed Well and RamSelect workshops, Mr Warner has a close understanding of the power of Australian Sheep Breeding Values (ASBVs) as an objective genetic selection tool. Click Here To Read Full Article »
Click Here To Read More News Articles »

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