Horses - Diet and Nutrition/over feeding oats


Hello ma'am. may i know how come over feeding oats leads to colic?

Hello Caine,

Thank you for your question.  Over feeding any cereal grain can increase the risk of colic in horses, oats are not alone in that respect.  In fact, compared to other cereal grains oats runs a much lower risk of causing gas colics.  A horse's digestive system can only safely digest cereal grains in the stomach.  A horse's stomach is quite small for the size of the animal holding only about 2-2.5 gallons of material.  The rate of passage through the stomach can be quite quick.  Overall, this means that the stomach has only a limited capacity to digest cereal grains.  If too much cereal grain is fed in one feeding, it can pass through the stomach without being digested.  

If undigested cereal grains make it to the horse's cecum, they will be fermented by bacteria.  This fermentation process generates gas (hence gas colic) and lowers cecal pH.  If the pH of the cecum lowers too much, forage digesting bacteria can be destroyed and cause additional digestive problems.  

Even though oats are relatively digestible, 85% pre-cecal digestibility in ideal conditions, feeding too much at one time can still increase the risk of gas colics.  Having said that, oats are still a better choice of cereal grains that corn or barley which have pre-cecal digestibility levels below 30%...which means that even in ideal feeding situations 70% of unprocessed corn and barley make it to the cecum where they will be fermented.  If you have to feed a cereal grain, oats are your best choice.

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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