G R Wiggans

Summary

Affiliation: Agricultural Research Service
Country: USA

Publications

  1. ncbi request reprint Short communication: Genetic evaluation of milking speed for Brown Swiss dairy cattle in the United States
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 90:1021-3. 2007
  2. ncbi request reprint Genetic parameters and evaluation of rear legs (rear view) for Brown Swiss and Guernseys
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 89:4895-900. 2006
  3. ncbi request reprint Accounting for pregnancy diagnosis in predicting days open
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 88:1873-7. 2005
  4. ncbi request reprint Type trait (co)variance components for five dairy breeds
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 87:2324-30. 2004
  5. ncbi request reprint Calving ease (Co)variance components for a sire-maternal grandsire threshold model
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350
    J Dairy Sci 86:1845-8. 2003
  6. ncbi request reprint Technical note: detection and adjustment of abnormal test-day yields
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 86:2721-4. 2003
  7. ncbi request reprint Genetic evaluations for mixed-breed populations
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 90:2434-41. 2007
  8. doi request reprint Distribution and location of genetic effects for dairy traits
    J B Cole
    Animal Improvement Programs Laboratory, ARS, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 92:2931-46. 2009
  9. doi request reprint Genomic imputation and evaluation using high-density Holstein genotypes
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, US Department of Agriculture USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 96:668-78. 2013
  10. ncbi request reprint Herd and state means for somatic cell count from dairy herd improvement
    H D Norman
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 83:2782-8. 2000

Detail Information

Publications36

  1. ncbi request reprint Short communication: Genetic evaluation of milking speed for Brown Swiss dairy cattle in the United States
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 90:1021-3. 2007
    ..The moderate heritability found for milking speed indicates that the evaluations (first released in May 2006) should be useful in detecting bulls with slow-milking daughters...
  2. ncbi request reprint Genetic parameters and evaluation of rear legs (rear view) for Brown Swiss and Guernseys
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 89:4895-900. 2006
    ..46 with rear legs (side view). With heritability near 0.10, RLRV should be useful in selection for improved locomotion. Release of genetic evaluations for RLRV began in May 2006 for Brown Swiss and Guernseys...
  3. ncbi request reprint Accounting for pregnancy diagnosis in predicting days open
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 88:1873-7. 2005
    ..The new prediction equations were implemented for November 2004 evaluations for daughter pregnancy rate...
  4. ncbi request reprint Type trait (co)variance components for five dairy breeds
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 87:2324-30. 2004
    ..11 for udder depth for Jerseys. The new estimates of (co)variance components should provide improved accuracy of type evaluations, particularly for traits that have had variance changes over time...
  5. ncbi request reprint Calving ease (Co)variance components for a sire-maternal grandsire threshold model
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350
    J Dairy Sci 86:1845-8. 2003
    ..009, sire-MGS) that yielded among the highest heritabilities (0.086, direct; 0.048, maternal) and a correlation of direct and maternal effects near the mean (-0.12) was selected for use in the implementation of a sire-MGS model for CE...
  6. ncbi request reprint Technical note: detection and adjustment of abnormal test-day yields
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 86:2721-4. 2003
    ..686 to 0.694 for protein (488,653 lactation pairs). Outlier adjustment improved the correlation between consecutive lactation yields and is applied routinely to TD records of cows for calvings since 1997...
  7. ncbi request reprint Genetic evaluations for mixed-breed populations
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 90:2434-41. 2007
    ..More research and education may be needed on using the new evaluations in the design of breeding programs. Implementation is expected in May 2007...
  8. doi request reprint Distribution and location of genetic effects for dairy traits
    J B Cole
    Animal Improvement Programs Laboratory, ARS, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 92:2931-46. 2009
    ..Results validate quantitative genetic assumptions that most traits are due to the contributions of a large number of genes of small additive effect, rather than support the finite locus model...
  9. doi request reprint Genomic imputation and evaluation using high-density Holstein genotypes
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, US Department of Agriculture USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 96:668-78. 2013
    ..Increasing the number of HD genotypes used for imputation above 1,074 did not improve the reliability of Holstein genomic evaluations...
  10. ncbi request reprint Herd and state means for somatic cell count from dairy herd improvement
    H D Norman
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 83:2782-8. 2000
    ..Most herds had test-day SCC that were substantially below legal bulk tank limits and could have met lower limits (e.g., 500,000 cells/ml)...
  11. doi request reprint Invited review: reliability of genomic predictions for North American Holstein bulls
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 92:16-24. 2009
    ..Reliability increased more by doubling the number of bulls genotyped than the number of markers genotyped. Genomic prediction improves reliability by tracing the inheritance of genes even with small effects...
  12. doi request reprint Short communication: genetic evaluation of mobility for Brown Swiss dairy cattle
    J R Wright
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 96:2657-60. 2013
    ..31-0.41). The mobility trait may provide a more accurate assessment of the structural soundness required for longevity than does the feet-legs composite...
  13. ncbi request reprint Confirmation and discovery of maternal grandsires and great-grandsires in dairy cattle
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 96:1874-9. 2013
    ..Because most dairy bulls over several generations have been genotyped, percentages of haplotypes shared with candidate males can accurately confirm, correct, or discover the sires, MGS, and even more distant ancestors of most animals...
  14. ncbi request reprint Stillbirth (co)variance components for a sire-maternal grandsire threshold model and development of a calving ability index for sire selection
    J B Cole
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 90:2489-96. 2007
    ..02 (0.16). A calving ability index combining stillbirth (SB) and calving ease (CE) was developed for inclusion in the Lifetime Net Merit index. The index was calculated as -4(sire CE)-3(daughter CE)-4(sire SB) -8(daughter SB)...
  15. doi request reprint Selection and management of DNA markers for use in genomic evaluation
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 93:2287-92. 2010
    ....
  16. ncbi request reprint Relationship of test-day somatic cell score with test-day and lactation milk yields
    R H Miller
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 87:2299-306. 2004
    ..To minimize milk loss, mastitis control is most important immediately pre- and postcalving for parity 1 and throughout lactation for parity 2...
  17. doi request reprint Technical note: Characteristics and use of the Illumina BovineLD and GeneSeek Genomic Profiler low-density bead chips for genomic evaluation
    G R Wiggans
    Animal Improvement Programs Laboratory, USDA, Beltsville, MD 20705, USA
    J Dairy Sci 96:1258-63. 2013
    ..Reliability for genomic evaluations using BovineLD and GGP genotypes was 3 percentage points higher than that for Bovine3K genotypes...
  18. doi request reprint Use of the Illumina Bovine3K BeadChip in dairy genomic evaluation
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 95:1552-8. 2012
    ..Prior to the availability of the 3K (August 2010), female genotyping accounted for 38.7% of the genotyped animals. In the past year, the portion of total genotypes from females across all chip types rose to 59.0%...
  19. doi request reprint Technical note: adjustment of traditional cow evaluations to improve accuracy of genomic predictions
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 94:6188-93. 2011
    ..9 percentage points for Jerseys when the predictor population was adjusted. The accuracy of genomic evaluations for Holsteins and Jerseys was increased through better use of information from cows...
  20. ncbi request reprint Development of a national genetic evaluation for cow fertility
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA paul aipl arsusda gov
    J Dairy Sci 87:2285-92. 2004
    ..Thus, recent selection for longevity may have slowed the long-term decline in fertility. Direct selection for fertility could halt or reverse the decline...
  21. doi request reprint Short communication: relationship of call rate and accuracy of single nucleotide polymorphism genotypes in dairy cattle
    T A Cooper
    Animal Improvement Programs Laboratory, Agricultural Research Service, US Department of Agriculture, Beltsville, MD 20705 2350, USA
    J Dairy Sci 96:3336-9. 2013
    ..Edits on call rate reduce the use of incorrect SNP genotypes to calculate genomic evaluations...
  22. doi request reprint Genomic inbreeding and relationships among Holsteins, Jerseys, and Brown Swiss
    P M Vanraden
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 94:5673-82. 2011
    ..Pedigree relationship matrices ignore common ancestry shared by base animals within breed and may not approximate genomic relationships well in multibreed populations...
  23. ncbi request reprint Characterization of Holstein heifer fertility in the United States
    M T Kuhn
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 89:4907-20. 2006
    ..Thus, there are currently no immediate plans to implement a US genetic evaluation for heifer CR...
  24. doi request reprint Technical note: adjustment of all cow evaluations for yield traits to be comparable with bull evaluations
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 95:3444-7. 2012
    ..The new adjustment was implemented by USDA in April 2011 and permits a fairer comparison of estimated genetic merit between nongenotyped and genotyped cows...
  25. ncbi request reprint Implementation of a sire-maternal grandsire model for evaluation of calving ease in the United States
    C P Van Tassell
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 86:3366-73. 2003
    ..A sire-MGS model was implemented in August 2002 for the national calving ease genetic evaluation system...
  26. doi request reprint The genomic evaluation system in the United States: past, present, future
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 94:3202-11. 2011
    ....
  27. doi request reprint Multiparity evaluation of calving ease and stillbirth with separate genetic effects by parity
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 91:3173-8. 2008
    ..Accuracy of the net merit index can be improved by adjusting weights to use evaluations for separate parities optimally...
  28. ncbi request reprint Genetic evaluation of stillbirth in United States Holsteins using a sire-maternal grandsire threshold model
    J B Cole
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 90:2480-8. 2007
    ..There was no evidence of a genetic trend for either trait. More complete recording of stillbirth scores would improve reliabilities and could allow for evaluations of other breeds...
  29. ncbi request reprint Genetic evaluation of calving ease for Brown Swiss and Jersey bulls from purebred and crossbred calvings
    J B Cole
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 88:1529-39. 2005
    ..Correlations among solutions and evaluations showed HO evaluations were not adversely affected by BS data and BS sires were reranked as compared with the BS-only evaluation...
  30. ncbi request reprint Genomic evaluation, breed identification, and discovery of a haplotype affecting fertility for Ayrshire dairy cattle
    T A Cooper
    Animal Improvement Programs Laboratory, Agricultural Research Service, US Department of Agriculture USDA, Beltsville, MD 20705 2350 Electronic address
    J Dairy Sci 97:3878-82. 2014
    ..3±2.5 percentage points for carriers of the haplotype as determined by 618 matings of carrier sire by carrier maternal grandsire. Genomic evaluations for Ayrshires were officially implemented in the United States in April 2013. ..
  31. doi request reprint Selection of single-nucleotide polymorphisms and quality of genotypes used in genomic evaluation of dairy cattle in the United States and Canada
    G R Wiggans
    Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 92:3431-6. 2009
    ..Genotypes from the Illumina BovineSNP50 BeadChip are of high accuracy and provide the basis for genomic evaluations in the United States and Canada...
  32. doi request reprint Technical note: adaptation of an animal-model method for approximation of reliabilities to a sire-maternal grandsire model
    G R Wiggans
    Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705 2350, USA
    J Dairy Sci 91:4058-61. 2008
    ..The modification provided a slight improvement over assuming MGS to be unknown and will be used for routine USDA evaluation of calving traits...
  33. ncbi request reprint Within-herd effects of age at test day and lactation stage on test-day yields
    J Bormann
    Animal Science Unit, Gembloux Agricultural University, B 5030 Gembloux, Belgium
    J Dairy Sci 86:3765-74. 2003
    ..The benefit of the within-herd-stage effects was confirmed in a random regression model by comparing variance components from models with and without random within-herd regressions and through log-likelihood ratio tests...
  34. ncbi request reprint Estimated heterogeneity of phenotypic variance of test-day yield with a structural variance model
    N Gengler
    National Fund for Scientific Research, B 1000 Brussels, Belgium
    J Dairy Sci 87:1908-16. 2004
    ..Repeatabilities of variances observed for a given class of herd, test-day, and milking frequency were 14 to 17% across nested variance subclasses based on lactation stage...
  35. ncbi request reprint Accounting for heterogeneous variances in multitrait evaluation of Jersey type traits
    N Gengler
    National Fund for Scientific Research, B 1000 Brussels, Belgium
    J Dairy Sci 89:3143-51. 2006
    ..This HV adjustment, which was implemented for USDA evaluations in May 2001 for Jerseys and in 2002 for other breeds, improves the accuracy of evaluations, particularly comparisons over time, by accounting for the change in variation...
  36. ncbi request reprint Adjustment for heterogeneous covariance due to herd milk yield by transformation of test-day random regressions
    N Gengler
    National Fund for Scientific Research, B 1000 Brussels, Belgium
    J Dairy Sci 88:2981-90. 2005
    ..The method suggests a number of innovative solutions to issues related to heterogeneous covariance structures, such as adjusted estimates in multibreed evaluation...