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G.R. Wiggans Animal Improvement Programs Laboratory Agricultural Research Service, USDA Beltsville, MD george.wiggans@ars.usda.gov G.R. WiggansSelect Sire committee meeting, March 2010 (1) Genomics: what we have and what is coming
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G.R. Wiggans Select Sire committee meeting March 2009 (2) How the system works l Studs and Breeds nominate animals through AIPL web site l Hair, blood, Semen, or extracted DNA sent to 1 of 4 Labs l Genotypes sent to AIPL monthly l Starting in April monthly updates will be released on the first Tuesday of most months l All official evaluations updated at tri-annual traditional runs
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G.R. Wiggans Select Sire committee meeting March 2009 (3) Recent improvements l Studs may submit pedigree and nominate in batch files l Pedigree from CAN, AUS, GBR automatically collected from web sites l Polygenic effect set at 10% to include genetic variation not captured by SNP l Net Merit calculated from component traits, not analyzed as a separate trait
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G.R. Wiggans Select Sire committee meeting March 2009 (4) Changes planned for April l Deviations of predictor cows adjusted to be like bulls with similar reliability to improve their contribution to accuracy l Genotypes of dams of genotyped animals imputed to add predictor animals l Sum of genomic relationships of each animal with the predictor animals used to improve estimation of Reliability
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G.R. Wiggans Select Sire committee meeting March 2009 (5) Imputation l Determine an animal’s genotype from genotypes of its parents and progeny l Genotype separated into sire and dam contributions. Identifies the allele on each member of a chromosome pair l Inheritance of haplotypes tracked l Accuracy of imputation improves with number of progeny l Crossovers during meiosis contribute to uncertainty
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G.R. Wiggans Select Sire committee meeting March 2009 (6) Genotyped Holstein by run Run Date Old*Young** Total MaleFemaleMaleFemale 0904760027119690194321944 09067883304911459297425365 09088512372812137367028047 09108568396513288479730618 10018974434814061603133414 10029378508615328762037412 10049770730016002873241804 * Animals with traditional evaluation ** Animals with no traditional evaluation
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G.R. Wiggans Select Sire committee meeting March 2009 (7) Cow Problem l Evaluations of elite cows appear biased upward l Cutoff studies show only a small benefit from including cows as predictors l Reducing heritability would reduce the problem but appears unacceptable l Adjustment of cow evaluations investigated
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G.R. Wiggans Select Sire committee meeting March 2009 (8) SD of Cow Deviation from PA 0 500 1000 1500 2000 2500 0.40.61.02.5 Daughter Equivalent (progeny) Std. Dev of Deregressed Value (Milk) Cow Bull
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G.R. Wiggans Select Sire committee meeting March 2009 (9) Mean of Cow Deviation from PA -400 -200 0 200 400 600 800 1000 20002001200220032004200520062007 Birth year Milk (lbs.) Cow Bull Cow SD Adj
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G.R. Wiggans Select Sire committee meeting March 2009 (10) Cow Adjustment Parameters l PTA calculated from adjusted deregressed values and used in PA l High reliability bulls (99%) not adjusted l Adjusted values used to calculate % traits Trait Std. DeviationMean HolsteinJerseyHolsteinJersey Milk.84.72784643 Fat.72.6727.531.4 Protein.77.6723.024.2
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G.R. Wiggans Select Sire committee meeting March 2009 (11) Effect of Adjustment on Holstein BiasRegressionGain REL NoYesDiffNoYesDiffNoYesDiff Milk (lb)-75.3-27.947.4.93.90-.0329.532.53.0 Fat (lb)-5.7-2.92.8.98.97-.0134.037.13.1 Protein (lb)-0.20.81.0.90.97.0725.027.12.1 Fat (%)0.0.97.99.0249.852.42.6 Protein (%)0.0.87.88.0138.841.52.7
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G.R. Wiggans Select Sire committee meeting March 2009 (12) Effect of Adjustment on Jersey BiasRegressionGain REL NoYesDiffNoYesDiffNoYesDiff Milk (lb)-44.081.5125.5.99.0010.819.68.8 Fat (lb)-7.37.915.2.78.84.069.418.28.8 Protein (lb)1.74.32.6.86.90.044.112.78.6 Fat (%)0.0.90.95.0529.937.67.7 Protein (%)0.0.87.93.0624.834.29.4
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G.R. Wiggans Select Sire committee meeting March 2009 (13) l Increased reliability of genomic predictions l Genomic evaluations of the top cows, top young bulls, and top heifers decreased l Among bulls, foreign bulls with a high proportion of genotyped daughters had largest changes l Adjusted PTA will be reported in XML traditional fields Cow Adjustment Summary
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G.R. Wiggans Select Sire committee meeting March 2009 (14) Reliability for young HO Bulls 0 500 1000 1500 2000 2500 3000 3500 4000 52535455565758596061626364656667686970717273747576777879 Milk REL Number of Bulls N = 15,226
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G.R. Wiggans Select Sire committee meeting March 2009 (15) Reliabilities for HO born ≥ 2005 No Traditional EvaluationWith Traditional Evaluation TraitMaleFemaleMaleFemale N1522675367523191 Milk (lb)73.973.785.877.9 Protein (lb)73.973.785.877.8 PL (months)64.063.670.167.0 SCS69.769.578.173.0 DPR (%)61.661.266.564.6 PTAT70.470.178.374.5 Sire CE64.961.780.863.5 Daughter CE60.259.069.561.8 Sire SB59.858.766.259.6 Daughter SB58.357.664.959.6 Net Merit ($)68.668.377.872.0
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G.R. Wiggans Select Sire committee meeting March 2009 (16) Bulls First Traditional Eval. Jan., 2010 Genomic AugustJanuary TraitNPTARELPTARELDiff PTA Milk70353376.347583.4-58 Protein70317.676.317.083.6-0.6 PTAT4711.070.41.077.50.0 Traditional AugustJanuary TraitNPARELPTARELDiff PTA Milk70365742.047874.9-179 Protein70322.142.017.074.9-5.1 PTAT4711.040.90.965.1-0.1
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G.R. Wiggans Select Sire committee meeting March 2009 (17) Cows First Traditional Eval. Jan., 2010 Genomic AugustJanuary TraitNPTARELPTARELDiff PTA Milk59477274.484575.473 Protein57025.574.429.475.13.9 PTAT2941.769.41.871.60.1 Traditional AugustJanuary TraitNPARELPTARELDiff PTA Milk59477435.694351.1167 Protein57026.235.232.949.86.7 PTAT2941.636.81.748.90.1
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G.R. Wiggans Select Sire committee meeting March 2009 (18) Accommodating chip diversity l Impute to highest density l Calculate SNP effects for all HD SNP l Mechanism for accounting for loss in accuracy due to imputation error needed w Percent missing may be enough l Only observed genotypes stored in database l Evaluations labeled as to source of genotype
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G.R. Wiggans Select Sire committee meeting March 2009 (19) Illumina 3K chip l SNP chosen to w Be evenly spaced w Include some Y specific SNP w Include 90 SNP for breed determination l Expect to impute genotypes for 43,385 SNP with high accuracy l Expect breeds to use 3K chip to replace microsatellites for parentage verification l Breeds allowed to genotypes bulls for parentage only.
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G.R. Wiggans Select Sire committee meeting March 2009 (20) Proposed Stud use of 3K l Genomic evaluation accuracy adequate for first stage screening l HD genotyping reserved for bulls acquired. w Confirm ID w Second stage selection l Lower cost enables genotyping more candidates l Savings could be applied to genotype more predictor bulls to meet EuroGenomics challenge
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G.R. Wiggans Select Sire committee meeting March 2009 (21) HD chip l Includes current 43,385 SNP so can replace 50K chip in current evaluations l 5,000+ genotypes at HD required to support imputation of HD from current 50K SNP l Expected gain in Rel < 2 l May allow HO genotypes to contribute to accuracy of JE & BS genomic evaluations
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G.R. Wiggans Select Sire committee meeting March 2009 (22) HD chip (Cont.) l Could share cost of HD genotyping with Europe to ensure enough animals to enable accurate imputation l Trend is toward higher densities. l Continued genotyping at 50K may be shortsighted l May allow reduction in polygenic effect giving increased accuracy
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G.R. Wiggans Select Sire committee meeting March 2009 (23) Will data recording survive l Progeny test no longer required to market bulls l In 2013, new entrants may have no data collection expense l Loss in accuracy of SNP effect estimates occurs over time l How much data is needed?
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G.R. Wiggans Select Sire committee meeting March 2009 (24) Assumptions About Future Data Trait and heritability Dtrs /YieldSCSDPR BullStat.30.10.04 100RELtrad.90.76.60 100RELpa.40.35.32 50RELtrad.83.65.48 50RELpa.38.32.29 RELtrad of foreign bulls multiplied by square of genetic correlation (.9) 2
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G.R. Wiggans Select Sire committee meeting March 2009 (25) Reliability from Additional Data Young bull REL for: Options to add data:YieldSCSDPR 9,000 current bulls726860 +16,000 from Europe878579 +7,500 with 50 dtrs848173 +7,500 with 100 dtrs858276 7,500 N. American bulls = 1500 / year over next 5 years
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G.R. Wiggans Select Sire committee meeting March 2009 (26) What replaces the PT program l G bulls will have 1,000s of daughters in their early Trad evaluations l Milk recording is justified for management information l Type data may come from breeder herds because they use G bulls l Data on new traits will require investment
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G.R. Wiggans Select Sire committee meeting March 2009 (27) Data into National Evaluations l Progeny Test herds could become Data Supply herds l Data acquisition could be supported by a fee based on bulls genotyped l Plan must be perceived as fair by all industry players l Quality Certification model could apply
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G.R. Wiggans Select Sire committee meeting March 2009 (28) Questions l How to match accuracy of evaluations from EuroGenomics l Should young bull purchases be based on 3K genotypes l How will continued flow of data into genetic evaluations be assured
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G.R. Wiggans Select Sire committee meeting March 2009 (29) Financial support l National Research Initiative grants, USDA l NAAB (Columbia, MO) w ABS Global (DeForest, WI) w Accelerated Genetics (Baraboo, WI) w Alta (Balzac, AB) w Genex (Shawano, WI) w New Generation Genetics (Fort Atkinson, WI) w Select Sires (Plain City, OH) w Semex Alliance (Guelph, ON) w Taurus-Service (Mehoopany, PA) l Holstein Association USA (Brattleboro, VT) l American Jersey Cattle Association (Reynoldsburg, OH) l American Brown Swiss Association (Beloit, WI) l Agricultural Research Service, USDA
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