Elanco Beef and Dairy Cattle Technical Consultant team
Our product lines are supported by a team of technical consultants to help you establish and achieve your herd health, economic productivity and operational sustainability goals. Learn more about our dairy and beef cattle experts.
Cattle and Feedlot Veterinary Technical Consultants
Cory Herr
Manager of the Beef Veterinary Technical Consultant group
Expertise: Feed additives, implants,drug development and regulatory.
Cory Herr has served Elanco for more than 20 years, working and managing teams within the research and development group and regulatory innovation where he has been a part of multiple product approvals and label extensions. For the past four years, he has served as manager of the beef nutritionist technical consultant group.
M. Wayne Ayers, DVM
Senior Beef Cattle Technical Consultant
Expertise: Parasiticide and insecticide management strategies.
Dr. M. Wayne Ayers is a Senior Beef Cattle Technical Consultant for Elanco Animal Health based out of Wilder, Idaho, supporting the western sales district. He earned his associate degree from Northern Montana College before going on to earn his bachelor’s degree and Doctor of Veterinary Medicine from Washington State University.
Upon graduation, Dr. Ayers owned and operated a mixed-practice clinic in Big Shady, Montana. In 2003, he joined a mixed practice in Caldwell, Idaho, which led him to the University of Idaho where he joined the faculty in 2007 as an assistant professor. He taught fourth-year veterinary students food animal production medicine and reproductive technologies. While he was at the University of Idaho, he conducted research, presenting it internationally, on Johne’s disease in sheep and goats. In 2013, Dr. Ayers returned to private practice until April 2018 when he accepted his current position with Elanco.
Dr. Ayers is an active member of the Elanco Global Sheep Council. In his current role, he conducts aftermarket research with Elanco products, contributes to research and development projects and assists manufacturing customers with research projects of their own. He has helped develop best practices strategies for Elanco's parasiticide and insecticide line of products.
T. Robin Falkner, DVM
Beef Cattle Technical Consultant
Expertise: Holistic management of feeder cattle systems for profit, people and planet outcomes.
Dr. T. Robin Falkner is a Beef Cattle Technical Consultant for Elanco Animal Health based out of Nashville, Tennessee, supporting the southeast sales district. He earned his Doctor of Veterinary Medicine from Mississippi State University.
He spent the first eight years of his veterinary career in private practice as a clinic owner focused on beef cattle and livestock markets. He served two years as an extension veterinarian at Kansas State University doing post-graduate work in ruminant nutrition and immunology, along with feeder cattle health, nutrition and management. Since 1999, he has worked with veterinarians and beef cattle operations across the country as both a private consultant and industry technical services veterinarian.
He is passionate about beef cattle, the families who care for them and the lands they graze. His expertise lies in holistic management of feeder cattle systems for profit, people and planet outcomes.
Ronald K. Tessman, DVM, Ph.D.,DACVIM, DACVPM
Beef Cattle Technical Consultant
Expertise: Bovine Respiratory Disease, antibiotics.
Dr. Ronald Tessman is a Beef Cattle Technical Consultant for Elanco Animal Health based out of Kansas City, Missouri, supporting feedyard producers. He earned his Doctor of Veterinary Medicine from Washington State University and a doctorate degree in veterinary pathology and pathobiology from the University of Missouri.
He has more than 17 years of experience and his career has included roles at Bayer Animal Health and Merial where he oversaw clinical efficacy studies crucial for the development of animal health products for farm animals. He also served as an adjunct assistant professor at the University of Missouri College of Veterinary Medicine.
Today, Dr. Tessman's role at Elanco Animal Health allows him to apply his wealth of knowledge and experience to the betterment of beef cattle production, supporting feedyard producers in Kansas City and beyond. His dedication to research, education and the development of animal health solutions continues to drive innovation and progress in the beef industry.
Jeremi W. Wurtz, DVM
Beef Cattle Technical Consultant
Expertise: Obstetrics work andreproductive services for cattle.
Dr. Jeremi W. Wurtz is a Beef Cattle Technical Consultant for Elanco Animal Health based out of Central City, Nebraska. He grew up on his family farm in eastern Nebraska raising corn, soybeans and Simmental cattle. He spent 12 years in mixed-animal private practice with a focus on beef cattle, including cow-calf, heifer development and stocker and feedlot. While in practice, he focused on veterinary student education, providing real-world experience and training to third- and fourth-year veterinary students. His passion lies in obstetrics work and reproductive services for cattle. His driving force is working with producers to reach their goals for livestock.
Wurtz earned his Doctor of Veterinary Medicine from Iowa State University.
Cattle and Feedlot Nutritionist Technical Consultants
Mike Brown, Ph.D.
Associate Advisor
Expertise: Feedlot cattle nutrition andmanagement, growth physiology and data analysis.
Dr. Mike Brown is an Associate Advisor with Elanco Animal Health based out of Canyon, Texas. His areas of focus include planning and monitoring research of approved products, analysis of research and customer data, development and delivery of technical and training materials, and direct in-field support for sales representatives.
Brown grew up on a crop and livestock operation in South Dakota where he began learning about animal nutrition from an early age. He earned his bachelor’s in animal science from South Dakota State University. After working at a feedyard in Nebraska and gaining additional experience in ruminant nutrition, he went on to earn his master’s and doctorate degrees in ruminant nutrition from New Mexico State University.
After completing his doctoral program, Brown joined the teaching faculty at West Texas A&M University. Serving in this role for 13 years, he led a research program on applied nutrition and management of feedlot cattle. He also served as major advisor/committee chair of 18 master's students and doctoral candidates, and authored or co-authored 38 peer-reviewed publications and book chapters along with more than 40 invited proceedings papers.
Before joining Elanco, Brown oversaw technical services of trace mineral products at Global Animal Products throughout Australia, Brazil, South Africa and the United States.
Brown is a member of the American Society of Animal Science and American Registry of Professional Animal Scientists (ARPAS), a former president of the Plains Nutrition Council and a former president of the Southern Great Plains chapter of ARPAS.
Jessica Gilreath, Ph.D.
Beef Technical Consultant
Expertise: Sustainable beefproduction, nutrition and greenhousegas emissions.
Dr. Jessica Gilreath is a Beef Technical Consultant for Elanco Animal Health based out of Texas.
Gilreath’s passion for working in the industry is rooted in her experiences growing up on her family’s farm in northwest Missouri where she gained a foundational understanding of livestock and crop production. She specializes in sustainable beef production systems and demonstrating progress in the feedlot industry, working with producers to maximize beef production while improving their operation’s environmental footprint and their net return.
Prior to joining Elanco, Gilreath worked as a sustainability engineer for Enriched Ag, bringing sustainability and grazing insights to producers. She also was a post-doctoral research associate and lecturer at Texas A&M University where she taught feedlot management and evaluated sustainable production practices in the cow-calf, stocker and feedlot sectors.
She earned a bachelor’s degree in animal science and agricultural economics as well as her master’s and doctorate degrees in animal science from Texas A&M University.
Justin Homm, Ph.D.
Beef Technical Consultant
Expertise: Feedlot nutrition and management.
Dr. Justin Homm is a Beef Technical Consultant for Elanco Animal Health based out of Lamar, Colorado, serving Colorado, Texas and Nebraska. His area of focus is feedlot nutrition and management.
Homm began his career as a technical consultant with Elanco, advising on animal nutrition and went on to work in research and data analytics for AgriBeef. He rejoined the Elanco team in 2020 and focuses on feedlot nutrition and management.
He earned his bachelor’s degree in animal nutrition from Oklahoma State University and his master’s degree in meat science from Kansas State University before earning his doctorate in animal nutrition from the University of Illinois at Urbana-Champaign.
Sara K. Linneen, Ph.D.
Beef Cattle Technical Consultant
Expertise: Cow-calf, stocker and backgrounder cattle nutrition. Byproductand alternative feedstuff applications.
Sara Linneen is a Beef Cattle Technical Consultant for Elanco Animal Health based out of Oklahoma City, Oklahoma, supporting cattle operations as a ruminant nutritionist. She works with cattle operations and feed mills throughout the U.S. on nutrition, feed delivery, feedstuff and forage evaluation, and feed mixing. She is also responsible for technical support for sales reps and producers focused primarily in cow-calf, grazing stocker cattle and backgrounding cattle operations. With a strong interest in research, Linneen is responsible for research furthering the understanding of approved products resulting in prolific publication in peer-reviewed journals.
Linneen grew up in southern Arizona where she received her bachelor’s degree in animal science from the University of Arizona. She went on to earn her master’s degree in animal science from Kansas State University and her doctorate degree in animal science from Oklahoma State University. Prior to joining Elanco, she held positions in both academia and industry focused on livestock production, feed milling and applied research.
Nathan Pyatt, Ph.D.
Beef Technical Advisor
Expertise: Feed additives, implants, Benchmark® trends, feed mixing, feed companydistribution and farmer-feeder segment.
Dr. Nathan Pyatt is a Beef Technical Advisor for Elanco Animal Health based in Illinois supporting producers in the Upper Midwest region.
In his current role with Elanco, he conducts product research and provides technical support for customers with a focus on performance and economic improvement opportunities with Elanco feed additives, implant programs and data analytics programs, such as Benchmark®.
Pyatt grew up on a diversified livestock and crop farm in southern Illinois. Prior to joining Elanco in 2010, he worked for ADM managing feed ingredient and beef product research. He resides in Monticello, Illinois, with his wife and three sons.
He completed his bachelor’s in animal science at Illinois State University and earned his master’s and doctorate degrees in ruminant nutrition from the University of Illinois.
Frank White, Ph.D.
Beef Cattle Technical Consultant
Expertise: Beef cattle nutrition andphysiology, implants, feed mixing andfeed company manufacturing.
Dr. Frank White is a Beef Cattle Technical Consultant for Elanco Animal Health based out of Oklahoma.
He has more than 20 years of experience in cattle nutrition, physiology and health, and has working knowledge and experience with cattle industries in Colorado, Idaho, Kansas, Nebraska, New Mexico, Oklahoma, Texas and Wyoming.
He earned his bachelor’s degree in animal science from Texas Tech University before going on to earn his master’s and doctorate degrees in cattle nutrition and physiology from Oklahoma State University.
Phil Rincker, Ph.D.
Manager of the Beef Nutritionist Technical Consultant group
Expertise: Meat science, beta-agonists, beef packers, meat quality
Dr. Phil Rincker serves as a technical advisor in the beef business unit of Elanco Animal Health where he strives to bridge the gap between beef producers and packers relative to the use of safe production technologies. Phil graduated from the University of Illinois with a bachelor’s in animal science and a master’s and PhD in meat science. Before Joining Elanco in 2011, he worked several years in R&D for a major U.S. beef packer. Phil is based in Indiana; he has worked in Elanco’s swine business, beef business, and has led various technical teams.
Dairy Technical Consultants
Andrew Holloway, DVM
Dairy Technical Consultant Leader
Expertise: Calf health, nutrition and management, cow comfort, dairy sustainability.
Dr. Andrew Holloway is a Dairy Technical Consultant Leader at Elanco Animal Health based out of Maryland serving the northeastern U.S. territory.
His professional interests include calf and heifer health, nutrition and management, cow comfort and reproductive management, and sustainable production. He is committed to advancing dairy farming practices and ensuring the well-being of livestock in the region.
Dr. Holloway’s passion for agriculture stems from his experience growing up on his family’s diversified farm in Maryland. He currently lives with his wife, two daughters and a plethora of various animal species in Darlington, Maryland.
He earned both his bachelor’s degree and Doctor of Veterinary Medicine from Virginia Tech.
Darren McGee, DVM
Dairy Technical Consultant
Expertise: Data analytics, nutrition, transition health, vaccines.
Dr. Darren McGee is a Dairy Technical Consultant for Elanco Animal Health based out of Starkville, Mississippi.
With over three decades of experience in the dairy industry, McGee is a seasoned dairy veterinarian and farm owner. He grew up working on his family’s dairy operation and, after completing his degree, contributed heavily to the veterinary work and financial management of his family’s herd. He then worked as a dairy technical advisor with Monsanto.
Today, McGee serves Elanco as a dairy technical consultant, where he uses his expertise to be a driving force in data analytics for the dairy industry. His passion for dairy farm data performance analysis led to his pivotal role in developing Elanco Knowledge Solutions for Dairy, providing valuable analytics and decision-making tools for dairy farmers. He also co-owns Heritage Dairy Farm, LLC, in Holly Springs, Mississippi.
He earned his Doctor of Veterinary Medicine from Mississippi State University.
Kevin Dhuyvetter, Ph.D.
Dairy Technical Adviser
Expertise: Economics, decision tools, data and analytics/statistical modeling.
Dr. Kevin Dhuyvetter is a distinguished Dairy Technical Adviser for Elanco Animal Health based in Michigan but serves producers across the U.S. He earned his doctorate degree in agricultural economics from Kansas State University.
Prior to joining Elanco’s technical team, Dhuyvetter spent 27 years at Kansas State University working as an extension specialist and research economist focusing on production economics, marketing and technology adoption.
In his current role with Elanco, Dhuyvetter’s primary focus is to analyze dairy herd health, production and economic data, analyze factors affecting the profitability of dairy operations and develop decision tools.
Sara Kvidera, Ph.D.
Dairy Technical Consultant
Expertise: Dairy farm sustainability, nutrition, gut health, research design.
Dr. Sara Kvidera is a Dairy Technical Consultant for Elanco Animal Health based in Iowa. She focuses on dairy cattle nutrition.
Kvidera found her passion for animal science growing up on a crop and cattle farm. This passion led her to Kansas State University where she earned her bachelor’s degree in animal science. While at Kansas State University, she fell in love with dairy cattle and went on to pursue her doctorate degree in ruminant nutrition from Iowa State University. Kvidera has studied and published in areas related to dairy cow metabolism, heat stress, inflammation, feed additives and gut health.
Kvidera has worked as a technical consultant in the industry since 2017 and joined Elanco’s dairy technical consultant team in 2021.
David Prentice, DVM
Dairy Technical Consultant
Expertise: Vaccines, anti-infectives, bioprotectants, colostrum.
Dr. David Prentice is a Dairy Technical Consultant for Elanco Animal Health based out of eastern Iowa, supporting Minnesota, Wisconsin, Idaho and Utah.
Dr. Prentice has more than 30 years of experience, including time as a private practice veterinarian in Iowa and California, and experience serving as a technical consultant for ABS Global and Balchem Corporation before joining Elanco.
He is a member of American Dairy Science Association and American Association of Bovine Practitioners and has served on the board of directors for the North American Intercollegiate Dairy Challenge.
He earned his bachelor’s degree and Doctor of Veterinary Medicine from Iowa State University. He also earned his master’s degree in dairy nutrition from the University of Wisconsin.
Erin Horst, Ph.D.
Dairy Technical Consultant
Expertise: Nutrition, calcium homeostasis, transition cow nutrition, research design.
Dr. Erin Horst is a Dairy Technical Consultant based out of Cottage Grove, Minnesota, supporting the southwestern U.S. Horst grew up on a swine farm near Van Horne, Iowa, and even though she was brought up around pigs, she enjoys working with ruminants. She earned her bachelor’s and doctorate degrees in animal science from Iowa State University.
During her doctoral program, Horst studied the energetic costs of the immune system in dairy cow health and performance, and researched how dietary strategies may help improve the host’s response to infection. Her research was aimed at providing nutritionists and producers with a cost-effective approach to improve animal welfare and economic profitability.
After completing her doctoral program, Horst worked as a technical consultant with Innovative Liquids before joining the Elanco team.
Kelly Mitchell, Ph.D.
Dairy Technical Consultant
Expertise: Nutrition, rumenmicrobiology, rumen microbial fatand amino acid metabolism.
Dr. Kelly Mitchell is a Dairy Technical Consultant at Elanco Animal Health based out of Visalia, California. Growing up in Tulare, California, she developed a passion for the dairy industry by actively participating in 4-H and FFA, and gained hands-on farm experience while working on several local farms.
Mitchell earned a bachelor’s degree in animal science and a master’s degree in animal biology from the University of California, Davis. During her master's program, she conducted pioneering research on ketosis in commercial herds, supported by the Feed Industry Fellowship funded by the California Dairy Research Foundation.
She went on to earn a doctorate in nutrition from The Ohio State University where she specialized in ruminant microbiology. She joined Elanco as a technical consultant, bringing her expertise to dairy operations in California and the Pacific Northwest, aligning with her commitment to enhancing dairy cattle health and nutrition.
Pádraig Lucey
Dairy Technical Consultant
Expertise: Dairy and replacement nutrition, machine learning/statistical analysis, epidemiology and infectious disease.
Pádraig Lucey is a Dairy Technical Consultant for Elanco Animal Health based out of Tulare, California, supporting California’s western dairy territory. He earned his master’s degree in preventative medicine and is pursuing his doctorate degree in animal biology and nutrition from the University of California, Davis. He is board certified with the American College of Veterinary Preventive Medicine specializing in preventive medicine and sub-specializes in epidemiology.
Originally from Ireland, Lucey began his career as a livestock practitioner in Northern Ireland. His journey led him to the UC Davis Veterinary Medicine Teaching and Research Center where he served as a resident veterinarian in dairy production medicine for three years, providing essential veterinary care to dairy farms in California's Central Valley and mentoring senior veterinary students. In this role, Lucey and conducted award-winning calf nutrition research that was recognized by the American Dairy Science Association.
His doctoral research has earned accolades from the California Animal Nutrition Conference, and he has been published in the International Journal of Animal Biosciences.
Lucey brings his expertise and enthusiasm for preventive health in dairy production to the Elanco team, as well as a commitment to research-based interventions for animal welfare and sustainability.
Trent Westhoff
Dairy Technical Consultant
Expertise: Nutrition, management, epidemiology, research design, transition cows, colostrum
Trent Westhoff is a Dairy Technical Consultant for Elanco Animal Health. A native of Iowa, Trent grew up involved in the daily operation of his family’s dairy, swine, and row crop farm. He received his Bachelor of Science degree in animal science from Iowa State University in 2019. During his undergraduate program, Trent’s interest in research evolved while completing three internships in the dairy food manufacturing and animal nutrition industries. He went on to earn a PhD from Cornell University in 2024 focused on nutrition, metabolism, management, and epidemiology. Westhoff’s doctoral research described the epidemiology of colostrum production and identified cow, farm management, and herd-level nutritional factors associated with colostrum yield and Brix %, as an indicator of colostrum quality.
Further, his research focused on evaluating the effect of pre- and postpartum metabolizable protein supply on metabolism, the immune response, and colostrum and milk production. His research and involvement have been recognized with the L.N. Hazel University Service Award, Maynard Award, and by the American Dairy Science Association. He joined Elanco Animal Health in 2025 and is committed to improving the productivity and health of animals, producers, and dairy businesses using data-driven decisions.
