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Nutrient Requirements of Horses and the NRC

When equine nutritionists want to review a horse’s diet they refer to Nutrient Requirements of Horses produced by the Committee on Nutrient Requirements of Horses and published by the National Academies Press – commonly referred to as “the NRC Requirements”.

Initially chartered by President Lincoln in 1863, “the National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council are private, nonprofit institutions that provide expert advice on some of the most pressing challenges facing the nation and the world.

“Known collectively as the National Academies, our organization produces groundbreaking reports that have helped shape sound policies, inform public opinion, and advance the pursuit of science, engineering, and medicine.”

The Committee, made up of experts in the field of equine nutrition with input from stakeholders, sponsors and public commentary, reviewed and evaluated the information in the previous edition (1989) in light of new information and advances in equine nutrition. 

Previous recommendations were clarified, and additional information was added in several areas including expanded nutrient discussions, considerations for breed differences and in-depth evaluations of other factors affecting management, nutrition and ration formulation and evaluation.

The “NRC Requirements” provide guidelines that represent the best-known available information.  Some of the requirements are based on established minimums known to prevent disease, similar to the model used in human “minimum daily requirements” while others, where there has been little or no research done with horses, has been extrapolated from other species. 

The formulas used to develop the requirements in the Daily Nutrient Requirements Table and in the online “Working Document” program can not take into consideration every nuance of breed, management, climatic or feed availability differences.  These guidelines should be used as a starting point – not a final result.

Any one who is serious about understanding equine nutrition can benefit from including a copy of Nutrient Requirements of Horses, Sixth Revised Edition in their library.  While the research evaluations can be heavy reading, the general discussions are rich in information and easy to follow.

The book - Nutrient Requirements of Horses, Sixth Revised Edition, National Academies Press, is available at

Another very readable interpretation of NRC guidelines is Understanding Equine Nutrition by Karen Briggs available at and other online bookstores.

29 December, 2011