Professor Julius van der Werf
University of New England, Armidale (NSW)
Tel: 02 6773 2092
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The Sheep CRC has been very successful in establishing a new capability for Australia’s sheep breeders to use genomic selection. The accuracy of using DNA data to predict breeding values is moderately high (between 0.20 and 0.50), and currently there are already well defined benefits for sheep breeders using the new technology to achieve faster genetic gain. However, further development is possible by increasing the accuracy and utility of genomic prediction. The current DNA testing (based on 50k SNP-chip data) does not allow prediction for animals that are genetically distant from the reference populations. Denser marker information, such as that provided with high-density SNP chips and full sequence information, is expected to provide a better understanding of the relationship between SNPs and functional genes. If successful, this new information will allow more widespread use of genomic predictions and maintain prediction accuracies over time.
The Program is conducted under two areas:.
An important component of both Projects is to develop and utilise cheaper DNA analysis systems in order to make genetic selection, based on DNA analysis, faster, more accurate and easy to implement in commercial breeding programs and production systems.
The goal of the proposed research program is to increase the reliability of genomic predictions in sheep and at the same time to reduce the cost of DNA testing to breeders. The program will also develop and investigate new designs for breeding programs to ensure that breeders capture the full benefits of the new technologies.
The ‘bio-bank’ of DNA stored from the Information Nucleus program provides an invaluable, and globally unique, resource for assessing the value of full-sequence DNA analysis. Research on full sequence databases is a new field of science. Close collaboration with the Dairy CRC is planned, as well as with a range of international groups with expertise in this area. We expect that this work will give the ability to prioritize gene regions and gene markers to use for genomic prediction. This allows development of more targeted sets of genetic markers, optimized to predict breeding values for important traits as well as testing for other genetic traits such as polledness and recessive deleterious mutations.
Capturing the opportunities provided by the continuous developments in genotyping technology combined with an ability to use targeted subsets of genetic markers will result in DNA testing tools that are cheaper and overall more informative and accurate.
Wider adoption of these genomic tools will depend on clear value propositions and effective ways to use the information that is obtained. We will work with breeders as well as commercial producers to explore ways to best employ these new genomic technologies. We aim to explore the value of genomic testing in commercial flocks for the purpose of benchmarking. Modelling the use of genomic information in breeder and commercial flocks can identify more clearly these value propositions, and decision tools can be developed and road tested to facilitate a cost-effective implementation of genomic testing in the Australian sheep industry.
The accuracy of predicting breeding value is directly related to the rate of genetic gain. More importantly, genomic selection allows more effective selection for a wider variety of traits, particularly those difficult to measure, such as reproduction and meat quality traits.
One of the limitations of the current genomic predictions is that they are limited to use in animals of the breeds tested in the genomic Resource Flock and/or the Information Nucleus Program. A more precise method of predicting breeding values from DNA analysis is expected to increase the overall accuracy of prediction, to facilitate predictions for a wider group of animals, including those that are less closely related to the Resource Flocks, animals from smaller breeds and composites, thereby allowing a wider use of genomic selection and a reduction of the cost of maintaining Resource Flocks for future predictions.
Genomic technologies will have an impact on the profitability of the sheep industry through faster genetic gain and better use of genetically improved animals. Increasing accuracy and reducing costs will increase both usage and benefits of genomic testing and more widely the uptake of genetic evaluation services. For new users of genetic evaluation services genetic gain will increase from $0.7/ewe/year to $2.00/ewe. Current users are expected to improve gains of $2.00 per ewe per year by 10-20%. A re-adjustment of genetic improvement toward important traits that are normally hard to measure will be critical for a sustainable breeding program.
Rapid, well balanced genetic gain creates a level of confidence in the long term future of the industry.
As DNA tests become cheaper and the prediction of breeding values becomes more accurate, there are increasing benefits associated with the effective use of the new DNA-based technology. The benefits of using DNA to predict parentage and breeding values include easier management systems at time of joining, an ability to run larger ram breeding flocks and to select and use rams at a younger age, leading to higher rates of genetic gain. Genomically benchmarking of commercial flocks creates more awareness of the value of genetically improved animals, it will assist in more informed ram buying decisions and it could be used to assort cohorts of animals in management and lamb supply chains.
Design of sheep breeding programs to capture benefits associated with the new DNA technology require interaction and engagement with breeders to overcome initial problems of early adopters and a complementary training program to ensure that the new opportunities are widely adopted and therefore contribute to significantly faster genetic gain in a wide cross section of the sheep population.
Ideas about the potential use of genomic technologies will be pilot tested in the industry and we will work with producers and breeders to assess the potential value of these genomic technologies in their businesses, and develop decision support tools to maximize the benefit of such information back to the user.