214 Awardee Talk: Using Nutrition to Improve Immune Competence in Horses

Abstract

Abstract Horse owners are increasingly interested in optimizing the health of their animals. In addition to targeted vaccination programs, they desire feeds and supplements that reduce inflammation or strengthen immune competence. Many nutrients and feed additives have widely recognized roles in host defense. Several of these have been evaluated in horses, including select trace minerals (Zn, Se), vitamins (E, C), amino acids (arginine, glutamine), fatty acids (omega-3, omega-6, conjugated linoleic acid), prebiotics, probiotics, postbiotics, and various non-nutritives (resveratrol, butyric acid). Collectively, the impact of these nutrients and feed additives on the status and functional capacity of the immune system have been variable. In most cases, the benefits are not realized in an already healthy horse but are demonstrable in animals under high stress (e.g., intense exercise, transport) or states of immunocompromise (e.g., inflammatory diseases, senior horses, foals). Immunonutrition research in horses is in its infancy compared to work in other livestock and humans. Yet demand from clientele managing and training horses for nutrition that addresses inflammation and gut health in horses is at an all-time high. Continued research in this area is needed but is challenged by reliance on industry funding and support, the need for non-terminal immunological variables that meaningfully reflect the impact of dietary intervention, and development of appropriate models that mimic real-world stressors yet permit greater control of external factors that contribute to variation. Nonetheless, exploration of how diet can modulate immune function remains an important area of research for maintaining the health and performance of horses under a variety of uses. Further, this area of investigation can also facilitate our understanding of nutrient requirements for horses under high levels of stress or those who are immunocompromised so that more targeted nutrition programs can be prescribed for these populations.