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Implementing and improving genomic evaluations. Genomic evaluation procedure. Nominate animals for genotyping Collect blood, hair, ear tissue, or semen Extract DNA and genotype Assign genotypes from image files - PowerPoint PPT Presentation
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G.R. WiggansAnimal Improvement Programs LaboratoryAgricultural Research Service, USDA Beltsville, MD
[email protected] Centennial (1) G.R. Wiggans
Implementing and improving genomic evaluations
G.R. Wiggans 2008AIPL Centennial (2)
Genomic evaluation procedure
Nominate animals for genotyping
Collect blood, hair, ear tissue, or semen
Extract DNA and genotype
Assign genotypes from image files
Check genotypes for call rate, parent-progeny consistency, and X homozygosity for bulls
Collect parent averages/estimated breeding values (EBV)
Calculate evaluations
Distribute evaluations to requesters
G.R. Wiggans 2008AIPL Centennial (3)
Nominate animals
Participating artificial-insemination (AI) organizations have 5-year exclusive rights to evaluate bulls genomically
Each AI organization genotypes its first-choice flushes, which usually avoids duplicate genotypes
Web-based system being developed to collect nominations Avoid duplication Confirm validity of identification (ID) and
pedigree
Breed associations developing cow genotyping service
G.R. Wiggans 2008AIPL Centennial (4)
DNA sources
Semen from Cooperative Dairy DNA Repository primary source of historical DNA
Cow genotypes primarily from associated research projects
Blood and hair the most common sources of DNA for calves and cows
Bulls in waiting genotyped from semen
Ear tissue being evaluated but has not been used
Some DNA from samples collected for parentage testing
G.R. Wiggans 2008AIPL Centennial (5)
DNA laboratories
Research Bovine Functional Genomics Laboratory (BFGL),
USDA (Beltsville, MD) University of Alberta (Edmonton, AB, Canada) University of Missouri (Columbia, MO) Illumina (San Diego, CA)
Commercial GeneSeek (Lincoln, NE) Genetics & IVF Institute (Fairfax, VA) Genetic Visions (Middleton, WI) DNA LandMarks (Saint-Jean-sur-Richelieu, QC,
Canada) Maxxam Analytics (Mississauga, ON, Canada) ABS (DeForest, WI, through SyGen/PIC, Franklin,
KY )
G.R. Wiggans 2008AIPL Centennial (6)
Assign genotypes
Each laboratory sends image files to BFGL
Methods developed to achieve consistent and high call rates
Direct reporting of genotypes to AIPL planned for December 2008
G.R. Wiggans 2008AIPL Centennial (7)
Check genotypes
90% call rate required
Each parent-progeny pair checked for conflicting homozygotes
Maternal grandsire (MGS) also checked with higher threshold of conflicts
Cases with many conflicts or no parent genotyped checked against all genotyped animals for possible parent
Heterozygous SNP on X counted(none expected for bulls)
G.R. Wiggans 2008AIPL Centennial (8)
Collect parent averages/EBV
Combined U.S.-Canadian analysis requires comparable evaluations for all animals
Interbull evaluations used for bulls
Canadian Dairy Network provides evaluations of Canadian genotyped cows and maternal ancestors of genotyped animals
Holstein USA provides type evaluations
Previous Interbull evaluations used at traditional triannual evaluation releases
G.R. Wiggans 2008AIPL Centennial (9)
Reliability of evaluations
Reliability from inverse of a matrix with order the number of genotyped animals
Approximation necessary as number of genotyped animals increases
Daughter equivalents discounted by 0.6 to represent better the reliability of 2003 data in predicting bulls first evaluated in 2008
G.R. Wiggans 2008AIPL Centennial (10)
Accurate genomic evaluations
Estimates of SNP effects required
Evaluations with high reliability provide the most information
Recent animals more useful than ones from earlier generations
Reliability of genomic evaluations increases with number of predictor animals
G.R. Wiggans 2008AIPL Centennial (11)
Genotyped animals (October 2008)
Breed Bulls CowsPredicto
rs
Holstein12,27
52,445 7,821
Jersey 1,205 369 1,428Brown Swiss
365 3 359
G.R. Wiggans 2008AIPL Centennial (12)
Schedule
Calculate SNP effects with each of 3 annual traditional evaluations
Calculate genomic evaluations once or more between traditional evaluations, monthly?
Recalculate SNP effects if significant number of predictor animals added
Use existing SNP effects if only young animals added
G.R. Wiggans 2008AIPL Centennial (13)
Official release in 2009
Added information from genomic evaluations propagated to evaluations of descendents without genotypes
National Association of Animal Breeders (NAAB) to manage bull-owner notification and sharing among AI organizations
Public release of genomic evaluations Cows soon after calculated Bulls when enrolled with NAAB or Canadian
AI organization Shared by agreement with owner
G.R. Wiggans 2008AIPL Centennial (14)
Improvements
Employ bar codes on sample containers to reduce errors and improve lab efficiency Widely used
Rely on breed associations to resolve parent-progeny genotype conflicts Will happen, especially if parentage
verification is switched from microsatellites to SNP
Enroll animals that might be genotyped at birth to avoid ID issues when genotyped Needs to be required; low cost enrollment
available
G.R. Wiggans 2008AIPL Centennial (15)
Plans to increase accuracy
Genotype more predictor bulls
Reach 1,500 Brown Swiss through foreign collaboration?
Increase genotyped Jerseys from both domestic animals and possible foreign collaboration
Investigate across-breed analysis to allow data from Holsteins to improve accuracy for Jerseys and Brown Swiss
G.R. Wiggans 2008AIPL Centennial (16)
Implications
Extraordinarily rapid implementation of genomic evaluations
Young bull acquisition and marketing as well as cow selection now based on genomic evaluations
Industry groups taking responsibility for genotyping and validation
G.R. Wiggans 2008AIPL Centennial (17)
Financial support
National Research Initiative grants, USDA
NAAB (Columbia, MO) ABS Global (DeForest, WI) Accelerated Genetics (Baraboo, WI) Alta (Balzac, AB) Genex (Shawano, WI) New Generation Genetics (Fort Atkinson, WI) Select Sires (Plain City, OH) Semex Alliance (Guelph, ON) Taurus-Service (Mehoopany, PA)
Agricultural Research Service, USDA