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Equine Research and Innovation Team

Synthesizing all of the research we conduct with the nutritional information on ingredients that our labs collect daily around the world, and turning it in to products that benefit horses, is a critical job. The following individuals are responsible for leading the research, development, and trials behind every Nutrena horse feed product that goes on the market.

Roy A. Johnson, M.S. received his Bachelors and Masters degrees from the University of Minnesota, St. Paul, MN in Animal Science and Agricultural Economics.  He was an instructor and assistant professor at the University of Minnesota-Waseca for 17 years where he taught equine nutrition, management, training and evaluation.

He develops the equine feeds for Cargill Feed & Nutrition in the U.S. and has conducted seminars in Brazil, Italy and Spain for owners and veterinarians.

Jim Ward D.V.M., a 1965 graduate of Texas A&M University, is an equine Management Consultant for Cargill Inc, a position he has held since 2000.

He is a Member of the Cargill Product Development Team and the Cargill Global Equine Team and currently serves as the general manager for Millennium Farms at Moon Lake, a Thoroughbred facility in Elm Grove, LA. Under Ward’s direction, Moon Lake Farm has been the location of several feeding trials conducted in association with Cargill.

Abby Keegan, M.S., PAS received her Master of Science degree from Kansas State University in Animal Science with focus in Equine Nutrition and Extension.  Abby has been professionally consulting with equine veterinarians, farm managers and horse owners on nutrition for 14+ years.  She guest lectured at several veterinary schools; taught Equine Nutrition for the Iowa State University Master of Equine Program; spoken at the AAEP Convention Sunrise Sessions, Wellington Equestrian Festival Lunch & Learn, and taught Continuing Education courses for veterinarians in several states. 

She is currently the Equine Innovation & Application Lead for Cargill working with formulation, research and technology.

Russell Mueller, M.S., PAS received his Master of Science degree in Equine Nutrition from Kansas State and is published in the Journal of Equine Veterinary Science.  He was an annual guest instructor for the KSU Veterinary Medical Teaching Hospital Equine Clinical Nutrition Course and has presented to clinical rounds at KSU and CSU Veterinary Schools as well.  Russell has conducted equine nutrition seminars in KS, MO, TX, CO, FL, OK, WY, NM, MI, WI, MN and IA.  He is certified with the American Registry of Professional Animal Scientists and a member in good standing with the Equine Science Society.

Dr. Marty Adams is an equine nutritionist for Cargill Animal Nutrition. He was formerly the equine nutritionist and horse feed manager for Southern States Cooperative. Dr. Adams served as an assistant/associate professor at Louisiana Tech University after graduate school, and then was the equine nutritionist for Seminole Feed before taking the position at Southern States. Dr. Adams has two B.S. degrees from Missouri State University, M.S. and Ph.D. degrees from the University of Missouri (Animal Science/Equine Specialty) and an ARPAS Equine (American Registry of Professional Animal Science) certification.

Heidi Armbrust, M.S. has her Master’s Degree in Public Health with a focus in Nutrition. Heidi has taught RACE approved continual education courses for Veterinary professionals in topics that include equine nutrition, parasitology, epidemiology, animal health and nutrition, public health and zoonotic disease.