Animal Breeding & Genomics
Ph.D., Animal Science, Virginia Tech, 1990
M.S., Animal Breeding, Texas A&M University, 1986
B.S., Animal Science, University of California-Davis, 1981
My research interests are in quantitative genetics and genomics with two main themes: (i) defining pragmatic strategies to improve the reliability of genetic evaluation, and thereby enhancing selection response, in livestock species; and, (ii) understanding how animals, changed through artificial selection, are influenced by and interact with their environment. This work involves a mix of theory, simulation, and field studies, with species emphases in sheep, beef, and poultry, with close collaborations in North America, Great Britain, and Australia.
Research projects that I currently have underway are: (i) predicting intake and diet selection in grazing cattle to improve the efficiency of cow-calf systems; (ii) developing an integrated genomic selection, management and herd health program to assist in the prevention and control of gastrointestinal nematode infection in sheep; (iii) establishing strategies to incorporate crossbred data into genetic evaluation of sheep; and, (iv) assessing the population dynamics, and long-term direct and correlated selection response, in broiler chickens selected for high and low body weight.
The focus of my graduate teaching is as the program director and instructor of four courses in a national graduate-level distance-delivered program in animal quantitative genetics and genomics (https://www.gpidea.org/program/quantitative-genetics-and-genomics). My undergraduate teaching includes an introductory course in animal breeding and genetics. I also have developed, and continue to support, an online simulation game (CyberSheep) that provides experiential learning in undergraduate and graduate instruction in animal genetics.
My teaching philosophy can be found at https://animalscience.unl.edu/ron-lewis-teaching-philosophy.
- Animal Breeding and Genetics (ASCI 330)
- Quantitative Genetics Applications of Matrix Algebra (distance-delivery)
- CyberSheep: a Genetic Simulation Game (distance-delivery)
- A Primer to Quantitative Genetics (distance-delivery)
- Selection Index Theory and Application (distance-delivery)
Although I have no formal extension appointment, I serve as the Technical Advisor to the National Sheep Improvement Program, the primary provider of genetic evaluation service for sheep and goat producers in the U.S.
Career total: 317
Referred Journal Publications (since 2015: 25; career total: 87)
In the following list of publications, an ‘*’ indicates that the publication was a collaboration with a current or former undergraduate, graduate, or post-doctoral student.
Becker, G. M., K. M. Davenport, J. M. Burke, R. M. Lewis, J. E. Miller, J. L. Morgan, D. R. Notter, and B. M. Murdoch. 2020. Genome-wide association study to identify genetic loci associated with gastrointestinal nematode resistance in Katahdin sheep. Anim. Genet. 51:330-335. doi.org/10.1111/age.12895
Davenport, K. M., C. Hiemke, S. D. McKay, J. W. Thorne, R. M. Lewis, T. Taylor, and B. M. Murdoch. 2020. Genetic structure and admixture in sheep from terminal breeds in the United States. Anim. Genet. 51:284-291. doi.org/10.1111/age.12905
Lewis, R. M., and G. C. Emmans. 2020. The relationship between feed intake and liveweight in domestic animals. J. Anim. Sci. 98. doi.org/10.1093/jas/skaa087
Vargas Jurado N.*, L. A. Kuehn, and R. M. Lewis. 2020. Lamb wool shedding is a good predictor of ewe wool shedding. J. Anim. Breed. Genet. doi:10.1111/jbg.12449
Artegoitia, V. M.*, A. P. Foote, R. M. Lewis, and H. C. Freetly. 2019. Metabolomics profile and targeted lipidomics in multiple tissues associated with feed efficiency in beef steers. ACS Omega 4:3973-3982. doi.org/10.1021/acsomega.8b02494
Parham, J. T.*, A. E. Tanner, K. Barkley*, L. Pullen*, M. L. Wahlberg, W. S. Swecker, Jr., and R. M. Lewis. 2019. Temperamental cattle acclimate more substantially to repeated handling. Appl. Anim. Behav. Sci. 212:36-43. doi.org/10.1016/j.applanim.2019.01.001
Parham, J. T.*, A. E. Tanner, M. L. Wahlberg, T. Grandin, and R. M. Lewis. 2019. Subjective methods to quantify temperament in beef cattle are insensitive to the number and biases of observers. Appl. Anim. Behav. Sci. 212:30-35. doi.org/10.1016/j.applanim.2019.01.005
Vargas Jurado N.*, A. E. Tanner, S. Blevins, J. Rich*, D. Fiske, W. S. Swecker, Jr., H. M. McNair, and R. M. Lewis. 2019. Choices between red clover and fescue in the diet can be reliably estimated in heifers post-weaning using n-alkanes. Animal 13:1907-1916. doi.org/10.1017/S175173111900017X
Petersen, J. L., R. M. Lewis, R. Embertson, S. J. Valberg, and S. J. Holcombe. 2019. Preliminary heritability of complete rotation large colon volvulus in Thoroughbred broodmares. Vet. Rec. 185:269. doi:10.1136/vr.105323
Zimmermann M. J.*, L. A. Kuehn, M. L. Spangler, R. M. Thallman, W. M. Snelling, and R. M. Lewis. 2019. Comparison of different functions to describe growth from weaning to maturity in crossbred beef cattle. J. Anim. Sci. 97:1523-1533. doi.org/10.1093/jas/skz045
See, G. M.*, T. R. Gruhot*, M. L. Spangler, and R. M. Lewis. 2018. Longitudinal analysis of weight showed little relationship with age at puberty in gilts. J. Anim. Sci. 96:4959-4966. doi.org/10.1093/jas/sky366
Vargas Jurado, N.*, K. M. Eskridge, S. D. Kachman, and R. M. Lewis. 2018. Using a Bayesian hierarchical linear mixing model to estimate botanical mixtures. J. Agric. Biol. Environ. Statistics 23:190-207. doi.org/10.1007/s13253-018-0318-9
Yu, H.*, M. L. Spangler, R. M. Lewis, and G. Morota. 2018. Do stronger measures of genomic connectedness enhance prediction accuracies across management units? J. Anim. Sci. 96:4490-4500. doi.org/10.1093/jas/sky316
Artegoitia, V. M.*, A. P. Foote, R. M. Lewis, and H. C. Freetly. 2017. Rumen fluid metabolomics analysis associated with feed efficiency in crossbred steers. Nature Sci. Rep. 7: 2864. doi.org/10.1038/s41598-017-02856-0
Artegoitia, V. M.*, A. P. Foote, R. G. Tait, Jr., L. A. Kuehn, R. M. Lewis, T. L. Wheeler, and H. C. Freetly. 2017. Endocannabinoids concentrations in plasma during the finishing period are associated with feed efficiency and carcass composition of beef cattle. J. Anim. Sci. 95:4568-4574. doi.org/10.2527/jas2017.1629
Ochsner, K. P.*, M. D. MacNeil, R. M. Lewis, and M. L. Spangler. 2017. Economic selection index development for Beefmaster cattle I: Terminal breeding objective. J. Anim. Sci. 95:1063-1070. doi.org/10.2527/jas.2016.1231
Ochsner, K. P.*, M. D. MacNeil, R. M. Lewis, and M. L. Spangler. 2017. Economic selection index development for Beefmaster cattle II: General-purpose breeding objective. J. Anim. Sci. 95:1913-1920. doi.org/10.2527/jas.2016.1232
Yu, H.*, M. L. Spangler, R. M. Lewis, and G. Morota. 2017. Genomic relatedness strengthens genetic connectedness across management units. G3: Genes|Genomes|Genetics. doi.org/10.1534/g3.117.300151
Artegoitia, V. M.*, A. P. Foote, R. M. Lewis, D. A. King, S. D. Shackelford, T. L. Wheeler, and H. C. Freetly. 2016. Endocannabinoids concentrations in plasma associated with feed efficiency and carcass composition of beef steers. J. Anim. Sci. 94:5177-5181. doi.org/10.2527/jas.2016-1025
Lewis, R. M., N. Vargas Jurado*, H. C. Hamilton*, and J. D. Volesky. 2016. Are plant waxes reliable dietary markers for cattle grazing western rangelands? J. Anim. Sci. 94(S6):93-102. doi.org/10.2527/jas.2016-0636
Vargas Jurado, N.*, K. A. Leymaster, L. A. Kuehn, and R. M. Lewis. 2016. Estimating heritability of wool shedding in a cross-bred ewe population. J. Anim. Breed. Genet. 133:396-403. doi:10.1111/jbg.12215
Eikje, L. S., and R. M. Lewis. 2015. Strong connectedness within Norwegian Cheviot and Fur Sheep ram circles allows reliable estimation of breeding values. J. Anim. Sci. 93:3322-3330. doi.org/10.2527/jas.2015-8946
Márquez, G. C.*, W. Haresign, M. H. Davies, R. Roehe, L. Bünger, G. Simm, and R. M. Lewis. 2015. Heterogeneous variances and genetics by environment interactions in genetic evaluation of crossbred lambs. Animal 9:380-387. doi.org/10.1017/S1751731114002717
Vargas Jurado, N.*, A. E. Tanner, S. R. Blevins, H. M. McNair, R. W. Mayes, and R. M. Lewis. 2015. Long-chain alcohols did not improve predictions of the composition of fescue and red clover mixtures over n-alkanes alone. Grass Forage Sci. 70:499-506. doi.org/10.1111/gfs.12134
Vargas Jurado, N.*, A. E. Tanner, S. R. Blevins, J. Rich*, R. W. Mayes, D. Fiske, W. S. Swecker, Jr., and R. M. Lewis. 2015. Feed intake and diet selection in Angus-cross heifers of two frame sizes at two stages of growth. J. Anim. Sci. 93:1565–1572. doi.org/10.2527/jas.2014-8453
Areas of ExpertiseBreeding & Genetics
Honors and RecognitionAlpha Zeta; Gamma Beta Phi Society; Gamma Sigma Delta; Phi Kappa Phi; Sigma Xi.
XCaliber Award for Excellence, Interdisciplinary Team Making Outstanding Contributions to Technology-enriched Learning Activities, Center for Innovation in Teaching, Virginia Tech, 2013.
Faculty Excellence Award, Great Plains IDEA, 2016.
Parents’ Recognition Award, University of Nebraska-Lincoln, 2017.
Darrell W. Nelson Excellence in Graduate Student Advising Award, College of Agricultural Sciences and Natural Resources and Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln, 2018.
ExperienceProfessor, Animal Breeding and Genomics, University of Nebraska-Lincoln, 2014-Present
Professor, Animal Genetics, Virginia Tech, 2011-2014
Associate Professor (tenured), Animal Genetics, Virginia Tech, 2004-2011
Associate Professor (pre-tenure), Animal Genetics, Virginia Tech, 2001-2004
Leader, Sheep Breeding Section, Scottish Agricultural College, 1998-2001
Animal Breeding Specialist, Scottish Agricultural College, 1992-1998
Geneticist, Department of Agriculture, Western Australia, Great Southern Agricultural Research Institute, 1990-1992
MembershipsAmerican Society of Animal Science
British Society of Animal Science
Poultry Science Association
North American Colleges and Teachers of Agriculture
American Society of Animal Science, Breeding and Genetics Joint Program, Committee Member, 2010 – 2012.
Poultry Science, Genetics Section, Associate Editor, 2010 – 2013.
World Congress on Genetics Applied to Livestock Production 2014, Vancouver, Canada, Scientific Committee Member, 2011 – 2014.
World Congress on Genetics Applied to Livestock Production, Permanent International Committee Member, 2014 – Present.
World Congress on Genetics Applied to Livestock Production 2018, Auckland, New Zealand, Session Chair/Moderator, 2017 – 2018.
Technical Advisor, National Sheep Improvement Program, 2016 – Present.
Vice-Chairman, Genetic Stakeholders Committee, American Sheep Industry Association, 2017 – Present.