Genomic-Only Breeding Values
Genomic-Only Breeding Values provide Merino producers with an early, accurate way to evaluate the genetic merit of individual sheep using DNA information alone.
What are Genomic-Only Breeding Values?
Unlike traditional breeding value systems that rely on performance recording and pedigree submission, Genomic Only Breeding Values (gBVs) testing predicts how animals will perform, and what they will pass on to their progeny, using genomic data compared with a large Merino reference population.
This information allows producers to rank rams and ewes within their flock, identify animals that align with their breeding objectives, and remove low-merit animals earlier in life. Because selection decisions can be made sooner and with greater confidence, genomic selection supports faster genetic progress, improved profitability and more sustainable flock development, even in flocks without phenotype recording programs.
Advantages of gBVs for sheep producers
- Select higher-merit animals with greater confidence
- Make earlier selection decisions
- Accelerate genetic progress within commercial and stud flocks
- Support ram breeding and replacement ewe selection
- Build a pathway toward more advanced genetic evaluation if desired
- Improve long-term productivity, welfare and profitability through data-informed breeding decisions
Get started with gBV testing
Make confident breeding decisions with XytoVet Genomic-Only Breeding Values testing. Get in touch with one of our Sales Consultants and find out more.
XytoVet gBV testing services
XytoVet delivers practical gBV testing designed specifically for Merino producers seeking individual animal insight without the complexity of full industry genetic evaluation programs. With a single DNA test, producers receive breeding value predictions across key wool, growth, carcase, reproduction, health and welfare traits, alongside flock-level context to guide selection decisions.
Producers who are focused on making within flock breeding decisions, but do not require as comprehensive data as ASBVs, are able to use gBVs without becoming a Sheep Genetics member. For many producers, gBVs represent a strong next step in delivering meaningful selection power without the additional data requirements of full breeding value systems.
Why choose us
Early genetic insight without phenotypic data
Access reliable genomic information early in life, without requiring phenotype data or membership programs.
More precise selection and faster decision making
Rank animals within your flock and confidently identify which to retain, join, market or cull, including improved selection of replacement ewes and sale rams.
Comprehensive trait coverage
Make informed decisions across major trait groups, including wool, growth, carcase, reproduction, health and welfare.
Clear reporting and expert support
Receive producer friendly reports with rankings, accuracy measures and indexes, backed by support from the XytoVet team on sampling, interpretation and next steps.
How gBV testing works
- Producers collect a tissue or blood sample from each animal to be sent to XytoVet and tested.
- DNA is analysed and compared against the Merino genomic reference population via the MERINOSELECT analysis.
- Results are presented in a simple format designed for on-farm decisions.
- Each animal receives:
- Parentage and Poll status report
- A 1–10 ranking within the flock, with 1 representing the top performers (see example in table below)
- Accuracy values indicating the reliability of each prediction
- Index scores that combine multiple traits into practical selection guides
- Flock benchmarking to provide context for average performance
It is important to note that gBVs are within-flock comparisons rather than industry-wide breeding values. They help identify the best and worst performers in your own flock, supporting immediate selection and culling decisions.
Understanding gBV Ranking Scores (1–10)
A gBV report contains a ranking score of 1-10 for each animal, with 1 being a good performer within the top 10% of the flock, and 10 being in the bottom 90% of the flock.
Reported traits that drive performance
Genomic-Only Breeding Values predict genetic performance across key traits, including:
- Wool production traits such as fleece weight, fibre diameter, staple length and fibre consistency
- Growth traits, including post-weaning and yearling weight
- Carcase traits such as fat depth and eye muscle depth
- Health and welfare traits, including breech wrinkle and worm resistance
- Reproductive indicators including weaning rate and condition score
Indexes are also provided to summarise performance across breeding objectives, including Fine Wool, Wool Production, Sustainable Merino and Merino Lamb.
