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Horses - Diet and Nutrition/horse not eating - heavy exercise


hello ma'am. how are you? a question for you.

my dad owns a filly at our local racetrack. my groom told me that whenever horses are exercised heavily, they dont eat their feed well for two to three days. may i know why?

Hello Caine,

Generally, horses who work more end up eating more.  The fact that your filly has decreased dry matter intake can be cause for concern, as it may eventually lead to weight loss and impaired performance.  There may be a few underlying factors at play, but I would start by looking at the filly's water intake and by determining if a high-starch diet is leading to overall fatigue.  Exercising horses have an additional requirement for water lost through rapid respiration and sweating while exercising.  If horses are deprived of water, or can not sufficiently rehydrate after exertion, they will eat less...especially if the feed is dry.  Ensure that the horse has unlimited access to water as soon as she has cooled down after exercise.  That is when horses are the thirstiest and likely to properly rehydrate.  High starch diets can, when a horse is exercising intensely, lend to acute fatigue in horses.  In short, the acid-base balance is tipped in extreme fatigue due in part to heavy starch loads.  Fatigue doesn't just affect the horse in her demeanor, it affects the horse at the cellular level.  This metabolic disturbance can have a deeper effect on metabolism.  Secondary to ensuring adequate water intake, ensure that the horse's diet contains a variety of energy sources that both meet its requirements and maintain a healthy metabolism.

Thanks, Corlena

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Corlena Patterson


I can help with any of your horse nutrition questions and concerns. I have been involved with horses for closing on 40 years, with a B.Sc in Animal Science and currently working on an M.Sc in Equine Science with the University of Edinburgh. I have owned my own feed store, consulted professionally as an equine nutritionist, and lectured in the fields of equine and dairy nutrition at the University level for 5 years. I have developed and currently market 'Ration-X', a ration formulation program for horses...designed for the everyday horse owner. I am happy to help in any way I can.


Experienced in developing and implementing feed programs for horses of all disciplines, creating custom horse supplements and managing inter-disciplinary equine facilities. Specialize in equine nutrition consulting.

The American Society of Equine Appraisers

'Stable Management' Handbook, Equine Canada.

M.Sc (Equine Science-current), B.Sc(Agr) Animal Science, Equine Sports Massage Therapy Certification, Farrier Certification, Equine Consultant Certification, Certified Equine Appraiser, Certified in Emergency Equine Rescue.

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