Texas Tech University

Meet the Team


Kristin Hales 

Kristin hales

Kristin Hales was raised on a farm in the Texas Panhandle.  She received a B.S. (2004) and M.S. (2006) in Animal Science from Oklahoma State University, with a Ph.D. in Animal Science from Texas Tech University in 2009, where she studied beef cattle nutrition and management.  Kristin began her career as a postdoctoral research associate at the USDA, ARS, Conservation and Production Research Laboratory in 2009 using respiration calorimetry to evaluate the energy content of wet distillers grains with solubles in diets with different corn processing methods.  In 2011, she was hired as a research animal scientist at the USDA, ARS, U.S. Meat Animal Research Center (MARC) to build a feedlot research program.  In this role, she conducted research to improve efficiency of beef cattle production, collaborating with meat scientists, geneticists, microbiologists, and agricultural engineers.  Kristin is recognized for her research in beef cattle energetics, demonstrating that the conversion of digestible energy to metabolizable energy is more efficient with high-concentrate diets than previously thought.

Since 2019, Kristin has served as the Thornton Distinguished Chair in the Department of Animal and Food Sciences at Texas Tech University.  Her research focuses on antimicrobial resistance in high-risk cattle and decreasing the use of antimicrobials in the feedlot production phase.  Additionally, she conducts applied feedlot nutrition research to meet the needs of the cattle feeding industry and provide relevant and useful solutions.  Her applied research program includes topics such as grain processing, bunk management, and nutritional strategies to decrease the prevalence of liver abscesses in finishing beef cattle.  Beyond research, she mentors M.S. and Ph.D. students and teaches graduate level Energetics, Nutrient Requirements of Beef Cattle, and Scientific Writing.

Dr. Hales currently serves as Associate Editor for Applied Animal Science and is the president-elect of the American Registry of Professional Animal Scientists.  She has served on the editorial board of the Journal of Animal Science, and she has chaired the ruminant nutrition committee of the Midwest Section of the American Society of Animal Science.  She has been a principal investigator on more than $2,200,000 in grants to study current issues in the feedlot industry, and her work is documented in 80 peer-reviewed publications and numerous scientific abstracts, proceedings, invited presentations, and book chapters.  Kristin lives in Lubbock, Texas with her husband Chris.

Michael Galyean

Dr. GalyeanMichael Galyean received his B.S. in Agriculture from New Mexico State University in 1973, and his M.S. in Animal Science (1975) and Ph.D. in Animal Nutrition (1977) from Oklahoma State University. He joined the faculty of the New Mexico State University in 1977, working on the main campus until 1990, when he moved to the Clayton Livestock Research Center in Clayton, NM to serve as Professor and Superintendent.

In 1996, he accepted a position as Professor of Animal Science with West Texas A&M University/Texas A&M University in Canyon, TX, where he worked until 1998, when he moved to Texas Tech University, where he holds the Thornton Distinguished Chair in Animal Science, with the highest faculty rank of Paul Whitfield Horn Professor.

He served as the Dean of the College of Agricultural Sciences and Natural Resources at Texas Tech from 2012 to 2016 and as Provost and Senior Vice President for Academic Affairs from 2016 to 2021. Dr. Galyean and his students and colleagues have authored 257 peer-reviewed journal articles, 60 invited papers and book chapters, and numerous other published proceedings, progress reports, experiment station articles, and abstracts.

Twenty-nine M.S. students, 33 Ph.D. students, and 9 post-doctoral research associates have worked under his guidance, and his research has been supported by more than $2.6 million in grant funds. Dr. Galyean served as a member of the National Research Council Subcommittee on Beef Cattle Nutrition and the Committee on Animal Nutrition and served as chair of the 2016 National Academy of Sciences, Engineering, and Medicine Committee on Nutrient Requirements of Beef Cattle.

He was President of the Western Section of the American Society of Animal Science (ASAS) and three times a member of the Board of Directors of ASAS. In addition, he served three terms on the Editorial Board of the Journal of Animal Science, one term as a Section Editor, and he was Editor-in-Chief from 2002 to 2005. Dr. Galyean has served as President-Elect, President, and Past-President of both ASAS (2006 to 2009) and the American Registry of Professional Animal Scientists (2013 to 2015). He was named a Fellow of ASAS in 2010, and he received the ASAS Morrison Award in 2012, the FASS-AFIA New Frontiers in Animal Nutrition Award in 2013, the ASAS Western Section Distinguished Service Award in 2016, and was inducted into the Legends of Feedlot Nutrition by the Plains Nutrition Council in 2020. In 2021, he received a Distinguished Alumni Award from the Ferguson College of Agriculture at Oklahoma State University.

Graduate Students

Ashley Hoffman

Photograph of Ashley Hoffman

Ashley Hoffman grew up in Basehor, Kansas on her family's cow-calf/row crop operation. Growing up, she always had dreams of becoming a large animal veterinarian. This led her to Kansas State University, where she pursued a bachelor's degree in Animal Sciences. During her time at K-State, Ashley was a member of the collegiate horse judging team, cutting horse judging team, and was involved in undergraduate research. Throughout her involvement in undergraduate research, Ashley was able to find her true passion in ruminant nutrition. Upon choosing to forgo vet school, she began searching for other opportunities that would allow her to further her education, which led her to Texas Tech University. At Texas Tech, Ashley is pursuing a master's degree in feedlot cattle nutrition and her future goal is to serve as a consulting nutritionist for commercial feedlots throughout the Midwest. 

Colton Dornbach 

Colten DonbachMy name is Colten Dornbach, and I am a PhD student under Dr. Hales. My research interests at Texas Tech will focus on growing consumer trust in beef production and food safety. This will be accomplished through multiple studies investigating bacterial etiology and prevalence, as well as antimicrobial resistance, in feedlot cattle.

Originally from Minnetonka, a suburb of Minneapolis, my family moved south to Webster, MN shortly before I attended high school. Prior to moving, I had little agricultural experience. However, after purchasing two horses and trying my hand at raising pheasants and guineas, I decided to pursue a career as a veterinarian. To achieve this, I attended Colorado State University, and it was here where my passion for the agricultural industry began to grow. Between semesters, I worked on a 550 head cow-calf operation in the mountains of Colorado. Working long days, every day, I gained an immense appreciation for lifestyle many livestock producers endured, and I realized my true motivation in life was to better the modern livestock producer. After graduating from CSU with a bachelor's degree in Animal Science and a certification in Animal Nutrition, I took an industry position with SAb Biotherapeutics in South Dakota. Working with transchromosomic bovine, I gained an appreciation for research and data collection. Soon thereafter I met with Dr. Josh McCann at the University of Illinois and was awarded the Nesheim Fellowship to help me pursue my master's degree. While at UIUC, I developed a strong scientific research foundation, as well as gained invaluable working knowledge of the backgrounding, receiving, and finishing phases of the beef industry. In May of 2022, I successfully defended my master's thesis titled “Effects of injectable vitamin E around time of transit on receiving phase performance and investigating the relationship between acidosis risk and feeding behavior during finishing in beef steers.” 

Taylor Smock

Taylor SmockMy interest, appreciation, and passion for beef production began growing up on a ranch in Southeast Wyoming and has been the central tenet of my life since. I was active in FFA throughout high school, and went on to serve as the 2012-2013 Wyoming State FFA Sentinel. The pursuit of my formal education began at Casper College, where I earned an Associate's degree in Agriculture Communications. At this time, I also worked in the Department of Agriculture, organizing lamb, pig, and cattle sales, keeping records, and helping instructors with classes. I then transferred to Texas Tech University, where I completed my Bachelor's degree in Animal Science. It was here that I discovered my interest in the fed cattle industry, which led me to an internship at a feedlot in the Texas Panhandle. Since then, I've been hooked. After graduating in 2016, I returned to the same feedlot where I worked as a bunk reader, learning countless invaluable lessons about cattle behavior, feed milling, and general feedlot operations. This led me to a Master's program at West Texas A&M University. In addition to my graduate studies and research, I worked at the West Texas A&M Research feedlot and was a teaching assistant for Principles of Animal Science and Feeds and Feeding. I was also so fortunate to learn about agriculture internationally by completing a study-abroad assignment in Australia and New Zealand. Finally, I returned to Texas Tech University to complete a PhD program, which has been nothing short of a high-impact, hands-on, and always fascinating learning experience. We have the capacity to learn and research about nearly everything there is to know about feeding cattle, which has been the opportunity of a lifetime.

Dalton Line

Dalton LineMy name is Dalton Line, and I am originally from a small town in western Illinois. On my family's farm in Seaton, we put our skills and focus on our cow-calf and row crop operation. I was introduced to livestock production at an early age and have been captivated ever since. With my motivation for the livestock industry at an all-time high, I decided to take my next adventure to Ames, Iowa. In 2021, I graduated from Iowa State University with a Bachelor of Science in Animal Science. My focus groups were Bovine and Swine production. My interest in livestock animal production arose after being involved in the show cattle industry and working with the youth of our agricultural sector. While at Iowa State University, I was involved in Block and Bridle and undergraduate research, which helped me find my path to the American Maine-Anjou Association. With the American Maine-Anjou Association, I served a two-year term, and one of those was being voted President of the American Junior Maine-Anjou Association. From there, I could build connections across the country, which is when I decided to take the next step to further my career in the livestock production industry. I made the move to Lubbock and Texas Tech University because of the opportunities and experience that Dr. Hales has provided, along with the outstanding faculty and networking opportunities. My focus here at Texas Tech is Ruminant Nutrition and Beef Energetics, with an emphasis on Agriculture education and youth development. I hope to make an impact someday to build youth development, boost safe and educational beef practices, and enhance the beef industry.

Ashlee Hanratty

Ashlee HanrattyMy name is Ashlee Hanratty, and I am a current graduate research student under Dr. Kristen Hales. I was born and raised in Pueblo, Colorado on my family's cow-calf and row-crop operation alongside my parents and three younger siblings. Growing up I was a member of 4-H, showing market swine and beef. It was through my involvement in 4-H where I gained a great appreciation for nutrition because I realized we have the ability as producers to manipulate and influence an animal's performance and health through feed. My love for animals and the livestock industry led me to pursue a degree in Animal Science on a pre-vet track at Kansas State University. During my time in undergrad, I worked as a veterinary technician where I gained experience in the lab running blood tests, analyzing fecal samples, and aiding in routine animal care. I also had the opportunity to participate in a course-bed research project where my interest in grad school really piqued. It was through this experience in research I realized pursuing graduate school would allow me to combine my passion for nutrition and animal health with the chance to bring significant solutions to producers and the problems they face in their own operations. Once finished with my master's degree, I hope to obtain my PhD in Ruminant Nutrition and pursue a career as a consulting nutritionist. 

Nathan Long

NateI've always been grateful to have been raised in a rural setting. Growing up on my family's small commercial cow-calf operation in East Tennessee allowed me to actively get engaged with the livestock community from an early age and ultimately paved the way for me to obtain my bachelor's degree in animal science from the University of Tennessee. My undergraduate research experience in applied beef cattle nutrition and reproduction at the “real” UT piqued my interest in graduate school through the realization that I could offer producers science-based solutions to real-world problems. This realization led me here to Texas Tech to complete my master's degree in animal science where my research focused primarily on the use of metaphylactic antimicrobials at feedlot arrival and resulting antimicrobial resistance in Salmonella enterica, Escherichia coli, and Enterococcus spp. Upon completion of my Ph.D., I hope to serve as a state beef cattle extension specialist in the Southeast.


feed lot staff

Left to right: Jeff Manahan, Eric Rocha, Michael Reyna, Ric Rocha

Kirk Robinson

kirk robinsonKirk has a long history with Texas Tech University. As an undergraduate in the Department of Animal and Food Sciences, he worked on the Mericon construction crew that built the Burnett Center in 1983. He graduated with a B.S. in Animal Science in 1985 and a B.S. in Agricultural Education in 1986. After completing his B. S., he went on to teach high school for 1 year in Silverton. A few years later, from 1988 to 1990 Kirk was back at the Burnett Center, working full-time. Then from 1990 to 1991, Kirk completed an M.S. degree under the guidance of Dr. Reed Richardson in ruminant nutrition. In March of 1995, Kirk was hired by Dr. Rod Preston as the manager of the Burnett Center and in that role, he has worked with Drs. Preston, Galyean, and Hales. Throughout the years he has worked with and mentored scores of graduate and undergraduate students, many who have gone on to successful careers in the cattle feeding industry. In 2019, Kirk was presented the Masked Rider Award for excellence, leadership, and exemplary service to Texas Tech University.

Ric Rocha 

Ric was raised near Acuff, Texas and has worked at the Burnett Center since 1994. Dr. Rod Preston got to know Ric through collaborative research at Lubbock Feeders and hired him because of his keen eye for animal husbandry. Through the years Ric has been integral in the research at the Burnett Center. He continues to mentor undergraduate and graduate students on identifying sick cattle and proper implanting procedures. In 2018, Ric was presented the Masked Rider award for excellence, leadership, and exemplary service to Texas Tech University. Outside of working at the Burnett Center, Ric is active in the naval reserves.

Eric Rocha

eric rocha

Eric is a native of Idalou, Texas and grew up at the New Deal Farm. Eric has worked at the farm in some capacity since he was 16 years old. After graduating high school, Eric attended Eastern New Mexico University in Portales, NM. There he received a degree in exercise sport science in 2013. Eric began working full time for Dr. Hales in 2020. Eric is an avid crossfitter and resides in Lubbock with his son Ethan and daughter Emmy.



Jeff Manahan

jeff manahanJeff is a native of New Deal, Texas. He graduated from Texas Tech University with a B. S. in Animal Science in 2019. Jeff has always been interested in cattle and agriculture and was hired at the Burnett Center in August of 2019. Jeff is currently pursuing an M. S. in Animal Science with Dr. Hales and anticipates graduating in August 2023. Jeff raises Red Angus cows in his spare time and enjoys spending time with his family.

Burnett Center