Here are photos of Enrique E. Guerra gathering cattle in Mexico in the 1950's drought. Charlie Schreiner, III accompanied Mr. Guerra in bringing back the remnants of Criollo cattle roaming the desert mountains. Claud A. "Heck" Schrader consulted about phenotypes. Descendants of these animals went to the Wichita Mountains Wildlife Refuge. Scroll down to the bottom of this page to view a presentation by Mr. Guerra discussing the history of these animals.


The Genetic Ancestry of American Creole Cattle inferred from uniparental and autosomal genetic markers
Ginja, elo Gama, Cortes, Martin Burriel, Vega-Pla, Penedo, Sponenberg, Canon, Sanz, Alves do Egito, Alvarez, Giovambattista, Agha, Rogberg-Munoz, Aparecida Cassiano Lara, BioBovis Consortium*, Delgado & Martinez

The Genetic Origins Of Nguni Cattle From Southern Africa

New World cattle show ancestry from multiple independent domestication events
McTavish, Decker, Schnabel, Taylor & Hillis

A Genomic Approach for Distinguishing between Recent and Ancient Admixture as Applied to Cattle
Emily Jane McTavish and David M. Hillis

Decoding the Genetic History of the Texas Longhorn - a summary
Emily Jane McTavish published her DNA research in the Proceedings of the National Acedemy of Sciences.

Emily's supporting data

Emily's Entire published research

Second Version

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus
Amparo M. Martínez, Luis T. Gama, Javier Cañón, Catarina Ginja, Juan V. Delgado, Susana Dunner, Vincenzo Landi, Inmaculada Martín-Burriel, M. Cecilia T. Penedo, Clementina Rodellar, Jose Luis Vega-Pla, Atzel Acosta, Luz A. Álvarez, Esperanza Camacho, Oscar Cortés, Jose R. Marques, Roberto Martínez, Ruben D. Martínez, Lilia Melucci, Guillermo MartEinez-Velázquez, Jaime E. Muñoz, Alicia Postiglioni, Jorge Quiroz, Philip Sponenberg, Odalys Uffo, Axel Villalobos, Delsito Zambrano, Pilar Zaragoza
pdf version

Working under the supervision of Alfred W. Roark Centennial Professor David Hillis, Ph.D., we funded two summer research fellowships for Emily Jane McTavish, Graduate student in Ecology Evolution Behavior, Section of Integrative Biology at the University of Texas at Austin, to analyze 50K chip data from Texas Longhorns and compare that to 50,000 alleles mapped from 57 other breeds of cattle in effort to identify breed-specific markers. Their research continued with a training grant to help discover the origins and admixture of the Texas Longhorn. Emily integrated data across platforms (Illumina 50K data with Bovine Genome Project HapMap data with USDA MARC data). She and Dr. Hillis collaborated with Jared E. Decker, Postdoctoral Fellow University of Missouri; Robert D. Schnabel, Research Assistant Professor-Division of Animal Sciences, University of Missouri; Jerry Taylor, Professor and Wurdack Chair of Animal Genomics, University of Missouri; Dr. Amparo Martínez Martínez, University of Córdoba, Spain, working in cooperation with SERGA, the Spanish Society for the Conservation of Animal Genetic Resources; and Mike Heaton, Ph.D. with the USDA Meat Animal Research Center also contributed data to the research project. Using the data analysis software STRUCTURE, Emily identified breed specific SNPs that place various breeds along a linear scale. She developed analysis software that interprets Illumina 6K chip data to calculate percent Indicus in individuals for comparison with populations to determine breed.

Genetic Diversity Study on Iberian Cattle

Brazilian Curraleiro of African origin

Bovine Genome Project
We contributed longhorn DNA samples to be included as part of the Bovine Genome Project conducted by the Bovine Genome Lab at the Human Genome Sequencing Center at Baylor College of Medicine.

We are also participating in a comparative project begun by Dr. Gama from Portugal and Dr. Delgado from Córdoba, Spain on descendants of Iberian bovines. This study continues in the US on four lines of Spanish descent.

Genetic diversity, structure, and breed relationships in Iberian cattle
by: I. Martín-Burriel, C. Rodellar, J. Cañón, O. Cortés, S. Dunner, V. Landi, A. Martínez-Martínez, L. T. Gama, C. Ginja, M. C. T. Penedo, A. Sanz, P. Zaragoza and J. V. Delgado
Abstract (link), Full Text (pdf)

The following are links to longhorn genetics research findings.

A body of research by Kenneth K. Kidd, Ph.D., Department of Genetics, Yale University School of Medicine:

Nutritional Profile of Grassfed Texas Longhorn Beef (.pdf)


History of the Texas Longhorn told by Red Steagall and friends.

A curriculum for 4th and 7th Grade Texas History that explains the roll the Texas Longhorn played in defining the history of Texas, may be downloaded for use by any teacher, homeschooler or persons seeking educational materials to share with children. Also linked, are suggested activities and teaching aides that parallel the curriculum. A comprehensive history lesson is available that weaves in the Texas Longhorn beginning in 1521 through present day.

Enrique Guerra Interview (link to external video)

Will Rogers Article

Texas History and Social Studies

  1. Longhorn History (.pdf)
  2. Curriculum (.pdf)
  3. F1 cross study
  4. Map of Spain (.pdf)
  5. Brand Activity (.jpg)
  6. Tracks .pdf)
  7. Last 5000 (.pdf)
  8. Wikipedia Chinook explanation
  9. Cattle introduction to Americas map (.pdf)
  10. New Spain map (.pdf)
  11. Loading horses diagram (.pdf)
  12. Hat Styles (.jpg)
  13. Spurs (.jpg)
  14. Spanish Lasso (.jpg)

    Vaquero 16 1/2-minute video by Rogelio Agrasanchez 2003

Graves Peeler article

US Herd articles

Wildlife Refuge History
Additional WR Historical Info

American Heritage article

Woods Cattle article

Historical Videos:

Marks Family Salt Grass Trail Ride 1956

1936 Archival Footage of Mexican Horned cattle crossing the boarder into Texas at Eagle Pass.
Corraled and run through dipping vats to stop the spread of tick fever to European stock in the state.

Archival Footage of corraled Texas Horned Cattle 1897


This science curriculum is designed to meet Texas educational requirements and give a comprehensive overview of Genetics and Natural Selection including: phenotypes, genotypes, punnett squares, species adaptation to biomes and a comparison between natural selection and selective breeding.

  1. Horn Genetics (PowerPoint) + Bos Taurus Horn Genetics Worksheet (pdf)
    --Middle School Science, Grade 7 112.19.b
    Science Lesson in Genotypes and Phenotypes;  Punnett Square exercise in inheritance percentages
  2. Base Color (PowerPoint) + Bos Taurus Base Color Genetics Worksheet (pdf)
    --Middle School  Science, Grade 7 112.19.b
    Science lesson in heredity; genes, chromosomes, nucleus, alleles
    Punnett Square exercise in predicting color allele combinations
    --High School Biology 112.34.c
    Nucleic acids, Mendelian Genetics, commonality of genetic code
  3. Chromossomal Inheritance Diagram
  4. Bos Taurus DNA Genetics (PowerPoint) + a) scatter plot 1 (pdf) + b) DNA plot 1 (pdf) + c) DNA plot 2 (pdf) + World Map (pdf)
    --High School Biology 112.34.c
    Components of DNA, gene expression, evolutionary theory: 
    DNA fingerprinting, genetic modifications, and chromosomal analysis are used to study the genomes of organisms.
  5. Natural Selection 1 (PowerPoint) + Comparing Longhorn & Hereford Traits Worksheet (pdf)
    --Middle School Science, Grade 7  112.19.b 
    Science Lesson in Genetic variations within populations
    Natural Selection versus Selective Breeding
    --High School Biology 112.34.c
    In depth study of Natural Selection, taxonomy and hierarchical classification
  6. Natural Selection 2 (PowerPoint) + Comparing Cattle & their Ecosystems Worksheet (pdf)
    --Middle School Science, Grade 7  112.19.b
    Science Lesson in genetic variations within a species, Natural Selection, heredity and biomes
    --High School Biology 112.34.c
    Natural Selection causing changes in populations, environmental resources resulting in differential reproductive success, adaptation and diversity

    Four Part Series on Breed Conservation Practices by Phil Sponenberg DVM, PhD
  7. Conserving Endangered Genetic Resources Part 1 (PowerPoint)
  8. Breed Conservation Discovery Part 2 (PowerPoint)
  9. Breed Conservation for Security Part 3 (PowerPoint)
  10. Breed Conservation for Sustainability Part 4 (PowerPoint)

Phil Sponenberg, DVM, PhD Presentation on Conservation Breeding Selection for Texas Longhorn Cattle 29 minute .mov Video recorded Feb. 22, 2014 (146.9 MB)
Dr. Sponenberg explains the importance of genetic diversity through bull selection and selecting cows for fertility.

Enrique E. Guerra's Presentation on the History of Texas Longhorn Cattle 1867-Present 19 minute .mov Video recorded Feb. 22, 2014 (90.63 MB)
This video includes many photos from Mr. Guerra's personal collection of cattle gathered in Mexico in the 1950's and many of the early Wichita Mountains Wildlife Refuge cattle.