Why Oats Are the Safest Grain Choice for Your Horse

I hope you find this blog post helpful! If you want a custom diet specific to your horse, click here.

P.S. We love AI, but this content is 100% human generated. 💕

Author: Dr Nerida McGilchrist | PhD Equine Nutritionist and Founder of My Happy Horse

Oats and horses are well made for one another.

Of all of the cereal grains we can feed to horses, oats are the only grain that can be fed safely without being cooked.

Why?

For a few reasons… the first is that oats contain less starch than other grains like corn or barley.

And, horses can actually digest the starch contained in oats when it is in its natural/raw form in their small intestine. Which means only small amounts of starch will be left undigested and deposited into the hindgut.

AND even if the starch does get to the hindgut, it doesn’t cause the same shift and dysbiosis of bacteria and gives rise to less lactic acid production.

All these factors combine to mean that when we feed oats, horses are able to efficiently extract the energy they contain. And the oats don’t cause a negative shift in the microbes in your horse’s hindgut.

Oats v other grains

Unlike oats, if we feed uncooked corn or barley (which contain between 55 and 70%+ starch), only about 25% of the starch they contain is digested in the small intestine.

Meaning a huge amount of starch is left undigested and will be delivered to and fermented in the hindgut. When starch gets into the hindgut, starch fermenting bacteria ferment it very quickly and cause a build-up of acid.

This acid creates a condition called hindgut acidosis.

And hindgut acidosis has all sort of negative consequences for your horse, including changes in behaviour, energy-sucking systemic inflammation and laminitis.

The balance between fibre fermenting and starch fermenting bacteria is also put out of balance… the ‘good’ fibre fermenting microbial populations are reduced (and in severe cases, wiped out completely), while the less desirable starch fermenting microbes increase in numbers.

Where, when we feed uncooked oats, most of its starch is digested in the small intestine!

(Do note however that if we cook barley and corn, especially via extrusion, they become far more digestible and very safe to feed.)

A small part of my own PhD research showed that oat grain is more digested in vitro (in a test tube) by a horse’s natural starch digesting enzymes than it was by bacterial and fungal enzymes typically used in in vitro assays. And it was far more digested in vitro compared to other raw grains.

So there is just something about oats and horses… horses are able to digest oat starch well!

Harlow, 2015 also showed that oat starch is less of a problem in the hindgut than corn starch.

This researcher incubated corn and oat starch in test tubes with faecal material from horses and found (briefly) that oat starch caused a significantly smaller increase in starch fermenting bacteria than corn starch and gave rise to lower lactic acid production.

Triple safety catch in oats

So it seems oats has a triple safety catch built in for our horses.

First, it is lower in starch than other grains.

Second, horses can digest oat starch well in their small intestine, so most of its starch appears to be digested before it reaches the hindgut.

And third, if some starch does end up in the hindgut it appears less likely to upset the hindgut microbial populations present there. Which should mean your horse is able to maintain a healthy population of the ‘good’ fibre fermenting microbes on diets containing oats.

So if you need to feed a grain and either don’t have access to or don’t like ‘cooked’ grains for some reason, go for oats, they are definitely the safest choice for your horse.

And! Horses love them!

About the Author

Dr Nerida McGilchrist

Dr Nerida McGilchrist is an Australian equine nutritionist with a PhD and over two decades of experience. As the founder of Equilize Horse Nutrition, and advisor to some of the world's largest nutrition companies, she’s built an international reputation for blending science with practical solutions. Now, she’s bringing her expertise to My Happy Horse to make advanced nutrition accessible to all.