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Current Projects: Dr. Ignacy Misztal

Single-step approach to incorporating genomic information into EPDs

Research project: "Single-step national evaluation using phenotypic and genomic information"

Dairy breeding is undergoing a major shift, whereby progeny testing is greatly enhanced with estimates of a vast number of genetic markers evenly spaced across the genome. Availability of the Bovine 50KSNP chip has made genomic selection a reality. Estimates of SNP effects, from the current model, indicate that nearly all markers are having some effect upon all traits. Several published articles predict that this new technology will lead to a doubling of the rate of genetic progress.

Benefits of the genomic selection could be obtained in beef cattle after a sufficient number of bulls are genotyped with the SNP chip. However, differences in dairy and beef breeding and especially fewer high accuracy bulls need to be taken into account.

The current genomic predictions, in the dairy industry, are obtained from a multistep procedure. It starts with a regular evaluation using only phenotypic records, followed by a separate evaluation for animals using only genomic information, and the resulting genetic values from each evaluation are combined using a weighting process. Recent literature indicates that the multistep approach may create biases and inaccuracies especially when genotyped animals have greatly varying level of information or are from weakly connected subpopulations (e.g., ranches with mostly self-contained breeding programs).

Recent research at the University of Georgia in collaboration with INRA Tolouse discovered a computational method to run a genetic evaluation with joint pedigree-genomic relationships in a reasonable computing time. This creates the possibility of upgrading of current evaluations to a single-step methodology that fully incorporates the genomic information.

The first goal of this research is to develop and test the single-step methodology in beef growth data. The second goal is to upgrade the existing software available at UGA for mutibreed evaluation to fully account for the genomic information.

If successful, this project could allow using the genomic information for all traits evaluated currently and with accuracy higher than with multistep procedures.

Research Team (all from University of Georgia except as noted)

Dr. Ignacy Misztal, Project Director
Breeding and Genetics

Ignacio Aguilar (Ph.D. student)
Breeding and Genetics

Dr. Shogo Tsuruta
Breeding and Genetics

Dr. Keith Bertrand
Breeding and Genetics

Dr. Brett Middleton
Breeding and Genetics

Dr. Andra Nelson
Breeding and Genetics

Dr. Romdhane Rekaya
Breeding and Genetics

Dr. Andres Leggara (INRA, France)
Breeding and Genetics